Archive-name: cvs-faq
$Revision: 2.3 $		<<== Include this in your comments
$Date: 1993/08/13 18:00:10 $

===========================================================================
== Frequently Asked Questions about CVS (The Concurrent Versions System) ==
===========================================================================

    This document attempts to answer questions posed by users of CVS.

    CVS installers, administrators and maintainers looking for info on
    system setup should read the section entitled "Installing CVS".


    Disclaimer:

	Though every attempt has been made to ensure the veracity of the
	following material, no responsibility is assumed for any use, or
	for any consequences resulting from any use, of the information
	contained herein.  No guarantee of suitability for any purpose
	is offered or implied.  Nothing in this document may be assumed
	to represent the employers of its contributors.

	I also might have slipped in a whopper or two to see if you are
	paying attention.  ;-)  In other words, don't bet the house on
	anything you read here unless you have checked it out yourself.



    Send questions and answers (along with additions to, subtractions
    from, and divisions of existing questions -- no multiplications,
    square roots, or transcendental functions, my cabinet is full of them)
    to the author, who wrote all unattributed text: (Does it always
    feel strange to refer to oneself in the third person?)

		David G. Grubbs <dgg@think.com>


    To help readers of previous versions of this document, I will annotate
    each question with a change marker

    Change markers:  Column 1 will contain a:

	'-'	for a Question that has changed.
	'='	for an Answer that has changed.
	'#'	for an entry with changes to both Question and Answer.
	'+'	for a newly added Question and Answer.


    The markers indicate significant changes in content between major
    revision numbers.  Trivial changes, such as question reordering or
    spelling and grammar corrections are not marked.  If I need to delete
    a question, I'll move it to a "Deleted" section for a few revisions.
    Deletions will arise when new versions of CVS are released.  In the
    long run, any question that can be answered by "get the latest
    release" will be deleted.

    The minor revision number will change frequently.  If a minor revision
    change is large enough, I'll add a change marker.  At major revision
    changes the markers will be cleared and set again, based on the latest
    minor revision of the previous major revision.
    


    Editorial comments are delimited by pairs of "[[" & "]]".  They
    contain either references to the (usually unfinished) nature of the
    FAQ entry itself or version-specific comments to be removed (or
    altered) when new revisions of CVS are released.

    You may redistribute this as long as you don't take statements out
    of context.  Keep it together along with the revision number.


============================================
==  Section 0	====	Introduction	====
============================================

The questions in this document come from many sources in many forms.  Some
are simple, some verbose.  A few are difficult, but all of them have been
asked of the author at one time or another.  Some questions are really
three or more different problems rolled into one plaintive cry for help.
Others reveal one of the bugs or weaknesses of CVS.

CVS addresses some difficult problems to which there are no perfect
solutions.  CVS also changes over time as new features are required.

Therefore, the questions are about a complicated moving target.

Though in most cases I've tried to provide the simplest answer I can
think of, some of the *questions* are difficult to follow.  If you
aren't using CVS regularly, don't expect to understand everything.

A Frequently Asked Questions document is not a substitute for the man page
or any other documentation.  It is an attempt to answer questions.

You should also keep in mind that FAQs are not really intended to be
read in their entirety like a text book.  You should use "grep" or
your editor's search capability to hunt for keywords and read the
sections you need.


Questions are divided into five numbered Sections.  Sections are divided
into lettered sub-sections.  The questions are numbered sequentially
within each sub-section, though they are in no particular order.


	1. What is CVS?
	   A. What is CVS?  What's it for?  Why CVS?
	   B. Where do I find it?  Where can I find Help?
	   C. How does CVS differ from other similar software?
	   D. What do you mean by .  .  .? (Definitions)

	2. User Tasks
	   A. Getting Started
	   B. Common User Tasks
	   C. Less Common User Tasks
	   D. General Questions

	3. Commands
	   A. through P.  One section for each CVS command.

	4. Advanced Topics
	   A. Installing CVS
	   B. Setting up and Managing the Repository
	   C. Branching
	   D. Tricks of the Trade
	   E. Weirdness
	   F. Related Software
	   G. Other Systems

	5. Past & Future
	   A. Contributors.
	   B. Bugs and Patches
	   C. Development

	6. Table of Contents


Final note:

	Except for the "Past & Future" section, all answers in this
	document refer to the latest released version of CVS: 1.3.


============================================
==  Section 1	====	What is CVS?	====
============================================

----------------
-- Section 1A --	What is CVS?  What's it for?  Why CVS?
----------------

 **** Questions:

 1A.1	What does CVS stand for?  Can you describe it in one sentence?
 1A.2	What is CVS for?  What does it do for me?
 1A.3	How does CVS work?
=1A.4	What is CVS useful for?
=1A.5	What is CVS *not* useful for?
=1A.6	Why isn't it called OSCO (Online Source COntrol)?


 **** Answers:

 1A.1	What does CVS stand for?  Can you describe it in one sentence?

	"CVS" is an acronym for the "Concurrent Versions System".

	CVS is a "Source Control" or "Revision Control" tool
	designed to keep track of changes to files made by groups of
	developers working on the same files, allowing them to
	stay in sync with each other as each individual chooses.


 1A.2	What is CVS for?  What does it do for me?

	CVS is used to keep track of collections of files in a shared
	directory, called "The Repository".  Each collection of files
	can be given a "module" name, which is used to "checkout"
	that collection.

	After checkout, files can be modified (using your favorite
	editor), "committed" back into the Repository and compared
	against earlier revisions.  Collections of files can be
	"tagged" with a symbolic name for later retrieval.

	You can add new files, remove files you no longer want, ask for
	information about sets of files in three different ways,
	produce patch "diffs" from a base revision and merge the
	committed changes of other developers into your working files.


 1A.3	How does CVS work?

	CVS stores its files in a directory hierarchy, called the
	Repository, which is separate from the user's working directory.

	Files in the Repository are stored in a format dictated by the
	RCS commands CVS uses to do much of its real work.  RCS files
	are standard byte-stream files with an internal format described
	by keywords stored in the files themselves.

	To begin work, you execute the "checkout" command, handing it
	a module or directory you want to work on.  CVS copies each file
	in the specified module or directory out of the Repository and
	into a sub-directory created in your current directory.

	You may then modify files in the new sub-directory, building them
	into output files and testing the results.  When you want to make
	your changes available to other developers, you "commit" them back
	into the Repository.

	Other developers can check out the same files at the same time.
	To merge the committed work of others into your working files
	you use the "update" command.  When your merged files build
	and test correctly, you may commit the merged result.  This
	method is referred to as "copy-modify-merge", which does not
	require locks on the source files.

	At any time, usually at some milestone, you can "tag" the
	committed files, producing a symbolic name that can be handed
	to a future "checkout" command.  A special form of "tag"
	can produce a branch in development, as usually happens at
	"release" time.

	When you no longer plan to modify or refer to your local copy
	of the files, they can be removed.


=1A.4	What is CVS useful for?

	CVS is intended to be useful for three major activities:

	1. Multiple developers

	   The major advantage of using CVS over the older and simpler
	   tools like RCS or SCCS is that it allows multiple developers
	   to work on the same sources at the same time.

	   The shared Repository provides a rendezvous point for
	   committed sources that allows developers a fair amount of
	   flexibility in how often to publish (via the "commit"
	   command) changes or include work committed by others (via the
	   "update" command).


	2. Vendor releases

	   If you are making changes to a product distributed by someone
	   else, the CVS feature, called the Vendor Branch, allows you
	   to combine local modifications with vendor releases.

	   I have found this most useful when dealing with sources from
	   three major classes of source vendor:

		a. Large companies who send you tapes full of the latest
		   release (e.g. Unix OS vendors, database companies).

		b. Public Domain software which *always* requires work.

		c. Pseudo-Public sources which require medium amounts of
		   work.  (e.g. GNU programs, X, etc.)


	3. Branches

	   Aside from the "Vendor Branch", there are three kinds of
	   "branches in development" that CVS can support:

	   a. Your working directory can be treated as a private branch.

	   b. A Development branch can be shared by one or more developers. 

	   c. At release time, a branch is usually created for bug fixes.

	   (See 1D.9 and Section 4C for more info on branches.)

	   Although, at this writing, CVS's branch support is a bit
	   primitive, CVS was designed to allow you to create branches,
	   work on them for while and merge them back into the main
	   line of development.  Arbitrary sharing and merging between
	   branches is not currently supported.


=1A.5	What is CVS *not* useful for?

	CVS is not a build system.

	    Though the structure of your Repository and modules file
	    interact with your build system (e.g. Makefiles), they are
	    essentially independent.

	    CVS does not dictate how you build anything.  It merely stores
	    files for retrieval in a tree structure you devise.

	    CVS does not dictate how to use disk space in the checked
	    out working directories.  If you write your Makefiles or
	    scripts in every directory so they have to know the relative
	    positions of everything else, you wind up requiring the entire
	    Repository to be checked out.  That's simply bad planning.

	    If you modularize your work, and construct a build system
	    that will share files (via links, mounts, VPATH in Makefiles,
	    etc.), you can arrange your disk usage however you like.

	    But you have to remember that *any* such system is a lot of
	    work to construct and maintain.  CVS does not address the
	    issues involved.  You must use your brain and a collection
	    of other tools to provide a build scheme to match your plans.

	    Of course, you should place the tools created to support such
	    a build system (scripts, Makefiles, etc) under CVS.


	CVS is not a substitute for management.

	    Your managers and project leaders are expected to talk to
	    you frequently enough to make certain you are aware of
	    schedules, merge points, branch names and release dates.  If
	    they don't, CVS can't help.

	    CVS is an instrument for making sources dance to your tune.
	    But you are the piper and the composer.  No instrument plays
	    itself or writes its own music.


	CVS is not a substitute for developer communication.

	    When faced with conflicts within a single file, most
	    developers manage to resolve them without too much effort.
	    But a more general definition of "conflict" includes problems
	    too difficult to solve without communication between
	    developers.

	    CVS cannot determine when simultaneous changes within a single
	    file, or across a whole collection of files, will logically
	    conflict with one another.  Its concept of a "conflict" is
	    purely textual, arising when two changes to the same base file
	    are near enough to spook the merge (i.e. "diff3") command.

	    CVS does not claim to help at all in figuring out non-textual
	    or distributed conflicts in program logic.

	    For example: Say you change the arguments to function X
	    defined in file A.  At the same time, someone edits file B,
	    adding new calls to function X using the old arguments.  You
	    are outside the realm of CVS's competence.

	    Acquire the habit of reading specs and talking to your peers.


	CVS is not a configuration management system.

	    CVS is a source control system.  The phrase "configuration
	    management" is a marketing term, not an industry-recognized
	    set of functions.

	    A true "configuration management system" would contain
	    elements of the following:

		* Source control.
		* Dependency tracking.
		* Build systems (i.e. What to build and how to find
		  things during a build.  What is shared?  What is local?)
		* Bug tracking.
		* Automated Testing procedures.
		* Release Engineering documentation and procedures.
		* Tape Construction.
		* Customer Installation.
		* A way for users to run different versions of the same
		  software on the same host at the same time.

	    CVS provides only the first.


=1A.6	Why isn't it called OSCO (Online Source COntrol)?

	Better discount?  CVS is shorter?  (The international audience
	requires an explanation: Both CVS and OSCO are the names of large
	chains of Pharmacies (drug stores) in the U.S.)



----------------
-- Section 1B --	Where do I find CVS?  Where can I find Help?
----------------

 **** Questions:

 1B.1	How do I get more information about CVS?
 1B.2	Is there an archive of CVS material?
 1B.3	How do I get a copy of the latest version of CVS?
 1B.4	Is there any other documentation?  How about tutorials?
 1B.5	Is there a mailing list devoted to CVS?  How do I get on it?
 1B.6	What prayers are appropriate for each of the major denominations
	(e.g. 20's, 50's, 100's) when issuing complex CVS commands?
+1B.7	How do I get files out of the archive if I don't have FTP?


 **** Answers:

=1B.1	How do I get more information about CVS?

	1. The first thing you should do is read the man page.

	2. Type "cvs -H" for general help or "cvs -H command" for
	   command-specific help.

	3. Read the original CVS paper (in the source tree, under "doc").
	   It describes the purpose of CVS and some of its workings.  Note
	   that some of the emphasis (especially on multiple vendors
	   providing the same sources) is out of date.

	4. Read the man pages for RCS.

	5. Read the source code.

	6. Look in the "doc" directory in the FTP archive described
	   below.

	7. Read the gnu.cvs.info newsgroup.

	8. If you don't get the newsgroup, you can join the info-cvs
	   mailing list, described below.


 1B.2	Is there an archive of CVS material?

	An anonymous FTP area has been set up.  It contains many of the
	CVS files you might want, including documentation, patches and
	the latest release.

		ftp think.com
		>>> User:	anonymous
		>>> Passwd:	<Your Internet address>
		cd /pub/cvs
		get README
		get Index

	The README has more (and more up-to-date) information.  The Index
	contains a terse list of what is in the archive.


+1B.3	How do I get files out of the archive if I don't have FTP?

	Use one of the FTP<->Email servers.  These are the ones
	I've been told about:


	1. To use DEC's ftpmail service, type

		echo 'send help' | mail ftpmail@decwrl.dec.com
	   
	   which will send you a message telling you how to use Email to
	   retrieve files from FTP archives.


	2. If you are on BITNET, use Princeton's BITFTP server.  Type

		echo 'send help' | mail bitftp@pucc.princeton.edu

	   (It is likely that only BITNET addresses can use this one.)


	3. Other possibilities I've heard of from the net:
	   (Try the one closest to you.)

		ftpmail@sunsite.unc.edu
		ftpmail@cs.arizona.edu
		ftpmail@cs.uow.edu.au
		ftpmail@doc.ic.ac.uk


 1B.4	How do I get a copy of the latest version of CVS?

	The latest released version of CVS and all the programs it
	depends on should be available through anonymous FTP on any FSF
	archive.  The main FSF archive is at "prep.ai.mit.edu".  There is
	another archive at UUNET and other large Internet sites.

		Program(s)	Latest revision
		-----------	-----------------------
		CVS		1.3
		RCS		5.6.0.1
		GNU diff	2.3

	The GNU version of diff is suggested by both the RCS and CVS
	configuration instructions because it works better than the
	standard version.  If you plan to use dbm in the modules file, you
	might also want to pick up the GNU dbm library.

	It is a good idea not to accept the versions of CVS, RCS or diff
	you find lying on your system unless you have checked out their
	provenance.  Using inconsistent collections of tools can cause you
	more trouble than you probably want.

	The FTP archive mentioned above should contain the latest official
	release of CVS, some official and unofficial patches and possibly
	complete patched versions of CVS in use somewhere.


 1B.5	Is there any other documentation?  How about tutorials?

	Take a look at the "doc" sub-directory in the FTP archive.
	You should find a growing collection of additional CVS
	documentation there.

	Other sources:

	     1. Per Cederqvist's Texinfo manual.

		The latest version of the Texinfo manual written by Per
		Cederqvist is included in the "doc" area mentioned
		above.


	     2. Gray Watson's cvs_tutorial.

		There is a version of this document in the "doc" area.

	     3. Apparently there is at least one project at O'Reilly (on
		RCS/SCCS) that will include some info about CVS.


	[[Anything else?]]


#1B.6	Is there a mailing list or Usenet newsgroup devoted to CVS?
	How do I find them?

	An Internet mailing list named "info-cvs" grew out of the private
	mailing list used by the CVS 1.3 alpha testers in early 1992.  An
	associated Usenet newsgroup named "gnu.cvs.info" was created in
	August, 1993.

	The newsgroup and the mailing list are bidirectionally gatewayed,
	meaning that you only need access to one of them.  Anything sent
	to the mailing list will be automatically posted to "gnu.cvs.info"
	and anything posted to the newsgroup will be automatically mailed
	to "info-cvs".
 
	First try the newsgroup, since it is generally easier to read (and
	manage) than a mailing list.   Ask your system administrator
	whether you get the "gnu" hierarchy.  If so, select a newsreader
	and dive in.

	If you don't get any form of Usenet News (or don't get the "gnu"
	hierarchy), you can add yourself to the mailing list by sending an
	Email message to:

		info-cvs-request@prep.ai.mit.edu

	(Don't forget the "-request" or you'll send a message to the
	 whole list, some of whom are capable of remote execution.)

	Mail to the whole list should be sent to:

		info-cvs@prep.ai.mit.edu

	An archive of the mailing list and the newsgroup might appear
	someday in the CVS FTP archive.


 1B.7	What prayers are appropriate for each of the major denominations
	(e.g. 20's, 50's, 100's) when issuing complex CVS commands?

	Only what the traffic will allow, in small, unmarked bills
	delivered to me, Ralph Icebag, in a plain brown wrapper, by a
	brown-shoed square, in the dead of night.  (Apologies to
	Firesign Theater.)



----------------
-- Section 1C --	How does CVS differ from other similar software?
----------------

This section attempts to list programs purporting to cover some of the
same territory as CVS.  [[These are very sparsely documented here.  If you
know something about one of these tools, how about trying to flesh out an
entry or two?]]


 **** Questions:

=1C.1	How does CVS differ from RCS?
 1C.2	How does CVS differ from SCCS?
=1C.3	How does CVS differ from ClearCase?
=1C.4	How does CVS differ from TeamWare?
 1C.5	How does CVS differ from SunPro?
 1C.6	How does CVS differ from Aegis?
 1C.7	How does CVS differ from Shapetools?
+1C.8	How does CVS differ from TeamNet?
+1C.9	How does CVS differ from ProFrame?
+1C.10	How does CVS differ from CaseWare/CM?
+1C.11	How does CVS differ from Sublime?


 **** Answers:


=1C.1	How does CVS differ from RCS?

	CVS uses RCS to do much of its work and absolutely all the work
	of changing the underlying RCS files in the Repository.

	RCS comprises a set of programs designed to keep track of changes
	to individual files.  Of course, it also allows you to refer to
	whole sets of files on the command line, but groups are
	manipulated by iterating over those files.  There is no pretense
	of combined interaction between the files.

	CVS's main intent is to provide a set of grouping functions that
	allow you to treat a collection of RCS files as a single object.
	Of course, CVS also has to do a lot of iteration, but it tries
	its best to hide that it is doing so.  In addition, CVS has some
	truly group-oriented facets, such as the modules file and the CVS
	administrative files that refer to a whole directory or module.

	One group aspect that can be a bit confusing is that a CVS branch
	is not the same as an RCS branch.  To support a CVS branch, CVS
	uses "tags" (what RCS calls "symbols") and some local state,
	in addition to RCS branches.

	Other features offered by CVS that are not supported directly by
	RCS are

	     1. Automatic determination of the state of a file, (e.g.
		modified, up-to-date with the Repository, already tagged
		with the same string, etc.)  which helps in limiting the
		amount of displayed text you have to wade through to
		figure out what changed and what to do next.

	     2. A copy-modify-merge scheme that avoids locking the files
		and allows simultaneous development on a single file.

	     3. Serialization of commits.  CVS requires you to merge all
		changes committed (via "update") since you checked out
		your working copy of the file.  Although it is still
		possible to commit a file filled with old data, it is less
		likely than when using raw RCS.

	     4. Relatively easy merging of releases from external Vendors.



 1C.2	How does CVS differ from SCCS?

	SCCS is much closer to RCS than to CVS, so some of the previous
	entry applies.

	You might want to take a look at Walter Tichy's papers on RCS,
	which are referred to in the RCS man pages.

	[[More info here?]]


=1C.3	How does CVS differ from ClearCase?

	ClearCase is a client-server CASE tool for version management,
	configuration management, and process management.  ClearCase
	is an evolution of the popular DSEE tools, formerly available
	on HP/Apollo platforms.  ClearCase includes an X/Motif GUI,
	command-line interface, and C programmer API, and is currently
	available on Sun, HP, and SGI platforms.

	ClearCase uses a special Unix filesystem type, called "mfs"
	for "multi-version file system".  Conceptually, mfs adds
	another dimension to the regular Unix filesystem.  The new
	axis is used to store the different versions of files.  Each
	user makes a "view" into the file database by creating a
	special mfs mountpoint on their machine.  Each view has a set
	of flexible selection rules that specify the particular
	version of each file to make visible in that view.  You can
	think of a "view" as a workarea in CVS, except that the files
	don't really exist on your local disk until you modify them.
	This type of filesystem is sometimes called "copy-on-write"
	and conserves disk space for files that are read-only.
	Another advantage is that a view is "tranparent" in the sense
	that all of the files in a "view" appear to be regular Unix
	files to other tools and Unix system calls.  An extended
	naming convention allows access to particular versions of a
	file directly: "test.cc@@/main/bugfix/3" identifies the third
	version of test.c on the bugfix branch.

	ClearCase supports both the copy-modify-merge model of CVS and
	the checkin/checkout development model with file locking.
	Directories are versionable objects as well as files.  A
	graphical n-way merge tool is provided.  Like CVS, ClearCase
	supports branches, symbolic tags, and delta compression.
	ASCII as well as binary files are supported, and converters
	from RCS, SCCS, DSEE formats are also included.

	A make-compatible build facility is provided that can identify
	common object code and share it among developers.  A build
	auditing feature automatically records file dependencies by
	tracking every file that is opened when producing a derived
	object, thus making explicit Makefiles unnecessary.  Pre- and
	post-event triggers are available for most ClearCase
	operations to invoke user programs or shell scripts.
	User-defined attributes can be assigned to any version or
	object.  Hyperlinks between versioned objects can record their
	relationship.

	For more information, contact:

	  Atria Software, Inc.
	  24 Prime Park Way
	  Natick, MA 01760
	  info@atria.com

	  (508) 650-1193 (phone)
	  (508) 650-1196 (fax)

				Contributed by Steve Turner
			[extracted from the ClearCase 1.1.1 documentation]


=1C.4	How does CVS differ from TeamWare?

	TeamWare is a configuration management tool from Sun
	Microsystems.

	For more information, contact:

	  SunExpress, Inc.
	  P.O. Box 4426
	  Bridgeton, MO 63044-9863
	  (800)873-7869


 1C.5	How does CVS differ from SunPro?

	SunPro is advertised as the successor to "SCCS".

	[[Need more info here.]]


 1C.6	How does CVS differ from Aegis?

	Aegis appears to be a policy-setting tool that allows you to use
	other sub-programs (make, RCS, etc.) to implement pieces of the
	imposed policy.

	The initial document seems to say that most Unix tools are
	inadequate for use under Aegis.

	It is not really similar to CVS and requires a different mindset.

	[[Need more info here.]]


 1C.7	How does CVS differ from Shapetools?

	Shapetools includes a build mechanism (called Shape, not
	surprisingly) that is aware of the version mechanism, and some
	dependency tracking.  It is based on a file system extension
	called Attributed File System, which allows arbitrary-sized
	"attributes" to be associated with a file.  Files are versioned in
	a manner similar to RCS.  Configurations are managed through the
	Shapefile, an extension of the Makefile syntax and functionality.
	Shape includes version selection rules to allow sophisticated
	selection of component versions in a build.

	Shapetools' concurrency control is pessimistic, in contrast to
	that of CVS.  Also, there's very limited support for branching and
	merging.  It has a built-in policy for transitioning a system from
	initial development to production.

				Contributed by Don Dwiggins


+1C.8	How does CVS differ from TeamNet?

	TeamNet is a configuration management tool from TeamOne.

	For more information, contact:

	  TeamOne
	  710 Lakeway Drive, Ste 100
	  Sunnyvale, CA 94086
	  (800) 442-6650

				Contributed by Steve Turner


+1C.9	How does CVS differ from ProFrame?

	ProFrame is a new system integration framework from IBM.
	ProFrame is compliant with the CFI (CAD Framework Initiative)
	industry standards, including the Scheme extension language.

	ProFrame consists of three major components: (1) the Process
	Manager that automates your local design methodology (2) the
	Design Data Manager handles configuration management, and (3)
	Inter-tool Communication to provide a communication path among
	tools running on heterogeneous servers.

	The Design Data Manager(2) is probably the appropriate
	component to compare to CVS.  The Design Data Manager provides
	version control with checkin/checkout capability,
	configuration management, and data dependency tracking.  A
	graphical data selection interface is provided.  Using this
	interface, you may create and manipulate objects and hierarchy
	structures, view the revision history for an object, and view
	and assign attributes to a design object.

	The ProFrame server currently runs only on RS600, but clients
	may be a wide variety of Unix platforms.  Contact IBM for the
	latest platform information.

	For more information, contact:

	  IBM
	  EDA Marketing and Sales
	  P.O. Box 950, M/S P121
	  Poughkeepsie, NY 12602
	  (800) 332-0066


				Contributed by Steve Turner
			[extracted from the ProFrame 1.1.0 datasheet]	


+1C.10	How does CVS differ from CaseWare/CM?

	CaseWare/CM is a software configuration management product
	from CaseWare, Inc.  CaseWare/CM may be customized to support
	a wide variety of methodologies, including various phases of
	the software lifecycle, and different access rights for users.

	A GUI is provided to view version histories and
	configurations.  A merge tools is also included.  CaseWare
	supports type-specific lifecycles, which allows different types
	of files to move through different lifecycles.  Also provided
	is a build facility to support automatic dependency analysis,
	parallel, distributed, and remote builds, and variant
	releases.

	CaseWare/CM has been integrated with other CASE tools,
	including FrameMaker, ALSYS Ada, CodeCenter/Object Center, HP
	SoftBench, and Software Through Pictures.  CaseWare also
	offers CaseWare/PT, a problem tracking system to integrate
	change requests with configuration management.

	Multiple vendors and operating systems are supported.

	For more information, contact:
	
	  CaseWare, Inc.
	  108 Pacifica, 2nd Floor
	  Irvine, CA  92718-3332
	  (714) 453-2200 (phone)
	  (714) 453-2276 (fax)

				Contributed by Steve Turner
			[extracted from the CaseWare/CM data sheet]


+1C.11	How does CVS differ from Sublime?

	Produced by AT&T.

	[[Need more info here.]]


----------------
-- Section 1D --	What do you mean by . . .? (Definitions)
----------------

 **** Questions:

#1D.1	What are "The Repository", "$CVSROOT" and "CVSROOT"?
 1D.2	What is an RCS file?
 1D.3	What is a working file?
 1D.4	What is a working directory (or working area)?
 1D.5	What is "checking out"?
=1D.6	What is a revision?
 1D.7	What is a "Tag"?
=1D.8	What are "HEAD" and "BASE"?
=1D.9	What is a Branch?
=1D.10	What is "the trunk"?
=1D.11	What is a module?
+1D.12	What does "merge" mean?


 **** Answers:


#1D.1	What are "The Repository", "$CVSROOT" and "CVSROOT"?

	The Repository is a directory tree containing the CVS
	administrative files and all the RCS files that constitute
	"imported" or "committed" work.  The Repository is kept in a
	shared area, separate from the working areas of all developers.

	Users of CVS must set their "CVSROOT" environment variable to the
	absolute pathname of the head of the Repository.  Most command
	line interpreters replace an instance of "$CVSROOT" with the value
	of the "CVSROOT" environment variable.  By analogy, in this
	document "$CVSROOT" is used as shorthand for "the absolute
	pathname of the directory at the head of the Repository".

	One of the things found in $CVSROOT is a directory named CVSROOT.
	It contains all the "state", the administrative files, that CVS
	needs during execution.  The "modules", "history", "commitinfo",
	"loginfo" and other files can be found there.


 1D.2	What is an RCS file?

	A file, usually ending in ",v", containing the source text and
	the revision history for all committed revisions of a source
	file.  It is stored separately from the working files, in a
	directory hierarchy, called the Repository.

	RCS is the "Revision Control System" that CVS uses to manage
	individual files.


 1D.3	What is a working file?

	A disk file containing a checked-out copy of a source file that
	earlier had been placed under CVS.  If the working file has been
	edited, the changes since the last committed revision are
	invisible to other users of CVS.


 1D.4	What is a working directory (or working area)?

	The "checkout" command creates a tree of working directories,
	filling them with working files.  A working directory always
	contains a sub-directory named ./CVS containing information
	about working files and the location of the directory within the
	Repository that was used to create the working directory.

	A working directory is the place where you work and the place
	from which you "commit" files.


 1D.5	What is "checking out"?

	"Checking out" is the act of using the "checkout" command to
	copy a particular revision from a set of RCS files into your
	working area.  See the "checkout" command in Section 3C.


=1D.6	What is a revision?

	A "revision" is a version of a file that was "committed" (or
	"checked in", in RCS terms) some time in the past.  CVS (and
	RCS) can retrieve any file that was committed by specifying its
	revision number or its "tag" (or symbolic name, in RCS terms).

	In CVS, a "tag" is more useful than a revision number.  It usually
	marks a milestone in development represented by different revision
	numbers in different files, all available as one "tagged"
	collection.

	Sometimes the word "revision" is used as shorthand for "the file
	you get if you retrieve (via "checkout" or "update") the given
	revision from the Repository."


 1D.7	What is a "Tag"?

	A "Tag" is a symbolic name, a synonym or alias for a
	particular revision number in a file.  The CVS "tag" command
	places the same "Tag" on all files in a working directory,
	allowing you to retrieve those files by name in the future.


=1D.8	What are "HEAD" and "BASE"?

	BASE and HEAD are built-in tags that don't show up in the "log"
	or "status" listings.  They are interpreted directly by CVS.

	"HEAD" refers to the latest revision on the current branch in the
	Repository.  The current branch is either the main line of
	development, or a branch in development created by placing a
	branch tag on a set of files and checking out that branch.

	"BASE" refers to the revision on the current branch you last
	checked out, updated, or committed.  If you have not modified
	your working file, "BASE" is the committed revision matching it.

	Most of the time BASE and HEAD refer to the same revision.  They
	become different for two reasons:

	1. Someone else changed HEAD by committing a new revision of your
	   file to the Repository.  You can pull BASE up to equal HEAD by
	   executing "update".

	2. You moved BASE backward by executing "checkout" or "update"
	   with the option "-r <rev/tag>" or "-D <date>".  CVS records a
	   sticky tag and moves your files to the specified earlier
	   revision.  You can clear the sticky tag and pull BASE up to
	   equal HEAD by executing "update -A".


=1D.9	What is a Branch?

	Any mechanism that allows one or more developers to modify a
	physically separate copy of a file without affecting anyone other
	than those working on the branch.

	There are four kinds of branches CVS deals with:

	1. The Vendor Branch.

	   A single vendor branch is supported.  The "import" command
	   takes a sequence of releases from a source code vendor (called
	   a "vendor" even if no money is involved), placing them on a
	   special "Vendor" branch.  The Vendor branch is considered part
	   of the "Main line" of development, though it must be merged
	   into locally modified files on the RCS Main branch before the
	   "import" is complete.

	   See Section 3H ("import").

	2. Your Working directory.

	   A checked-out working directory, can be treated like a private
	   branch.  No one but you can touch your files.  You have
	   complete control over when you include work committed by
	   others.  However, you can't commit or tag intermediate versions
	   of your work.

	3. A Development branch.

	   A group of developers can share changes among the group,
	   without affecting the Main line of development, by creating a
	   branch.  Only those who have checked-out the branch see the
	   changes committed to that branch.  This kind of branch is
	   usually temporary, collapsing (i.e. merge and forget) into the
	   Main line when the project requiring the branch is completed.

	   You can also create a private branch of this type, allowing an
	   individual to commit (and tag) intermediate revisions without
	   changing the Main line.  It should be managed exactly like a
	   Development Branch -- collapsed into the Main line and
	   forgotten when the work is done.

	4. A Release branch.

	   At release time, a branch should be created marking what was
	   released.  Later, small changes (sometimes called "patches")
	   can be made to the release without including everything else on
	   the Main line of development.  You avoid forcing the customer
	   to accept new, possibly untested, features added since the
	   release.  This is also the way to correct bugs found during
	   testing in an environment where other developers have continued
	   to commit to the Main line while you are testing and packaging
	   the release.

	   Although the internal format of this type of branch (branch tag
	   and RCS branches) is the same as in a development branch, the
	   purpose and the way it is managed are different.  The major
	   difference is that the branch is Permanent.  Once you let a
	   release out the door to customers, or to the next stage of
	   whatever process you are using, you should retain forever the
	   branch marking the release.

	   Since the branch is permanent, you cannot incorporate the
	   branch fixes into the Main line by "collapsing" (merging and
	   forgetting) the release branch.  For large changes to many
	   files on the release branch, you will have to perform a branch
	   merge using "update -j <rev> -j <rev>".  (See 4C.7)

	   The most common way to merge small changes back into Main line
	   development is to make the change in both places
	   simultaneously.  This is faster than trying to perform a
	   selective merge.

	See 1D.12 (merges) and Section 4C, on Branching for more info.


=1D.10	What is "the trunk"?

	Another name for the RCS Main Branch.  The RCS Main Branch is
	related, but not equivalent, to both the CVS Main branch and what
	developers consider to be the Main line of development.
	See 3H.3 and Section 4C on Branching.


=1D.11	What is a module?

	In essence, a module is a name you hand to the "checkout" command
	to retrieve one or more files to work on.  It was originally
	intended to be a simple, unique name in the "modules" file
	attached to a directory or a subset of files within a directory.

	The module idea is now a somewhat slippery concept that can be
	defined in two different ways:

	A. A module is an argument to "checkout".  There are three types:

	   1. An entry in the modules file.  A "module" name as described
	      in 'B.' below.

	   2. A relative path to a directory or file in the Repository.

	   3. A mixed-mode string of "modulename/relative-path".
	      Everything up to the first slash ('/') is looked up as a
	      module.  The relative path is appended to the directory
	      associated with the module name and the resulting path is
	      checked out as in #2 above.


	B. A module is a unique (within the file) character string in the
	   first column of the modules file.  There are five types:

	   1. A name for a directory within the Repository that
	      allows you to ignore the parent directories above it.

	      Example:

		  emacs  gnu/emacs


	   2. A name for a subset of the files within such a directory.

	      Example:

		  ls	unix/bin Makefile ls.c


	      The 2nd through Nth strings in the above must be *files*.
	      No directories, no relative pathnames.  To checkout more
	      than one directory by a single name, use an alias as
	      described in #5 below.


	   3. A relative pathname to a directory within the Repository
	      which, when checked out, creates an image of part of the
	      Repository structure in your current directory.

	      Example:

		  gnu/emacs -o /emacs.helper gnu/emacs

	      The files checked out are exactly the same as the files you
	      would get if the path weren't even in the modules file.  The
	      only reason to put this kind of relative pathname into the
	      modules file is to hook one of the helper functions onto it.


	   4. A relative pathname to a single file within the Repository
	      which, when checked out, creates something you probably
	      don't want:  It creates a directory by the name of the file
	      and puts the file in it.

	      Example:

		  gnu/emacs/Makefile -o /emacs.helper gnu/emacs Makefile

	      The file checked out is the same as what you would get if
	      you handed the relative pathname to the "checkout" command.
	      But it puts it in a strange place.  The only reason to do
	      this is to hook a helper function onto a specific file name.


	   5. An alias consisting of a list of any of the above, including
	      other aliases.

	      Example:

		  my_work  -a  emacs gnu/bison unix/bin/ls.c


	Another way to look at it is that the modules file is simply
	another way to "name" files.  The hierarchical directory
	structure provides another.  You should use whatever turns out to
	be simplest for your development group.

	      
	As an example, say you want to keep track of three programs, and
	want to be allowed to check out any combination of one, two or all
	three at a time.  Here are most of the combinations I can think
	of.  Experiment and choose what you want -- you won't need every
	possibility.


	# All directories in "world", even ones added later.
	world		world

	# All three programs by name.  They checkout into local dir.
	prog123	-a	prog1 prog2 prog3

	# All three programs by name.  They checkout into "world" subdir.
	wprog123 -a	wprog1 wprog2 wprog3

	# Individual progs checkout into dirs named "prog1", etc.
	prog1		world/prog1
	prog2		world/prog2
	prog3		world/prog3

	# Individual progs checkout into dirs named "world/prog1", etc.
	wprog1	-a	world/prog1
	wprog2	-a	world/prog2
	wprog3	-a	world/prog3

	# Pairs that checkout into local dir.
	prog12	-a	prog1 prog2
	prog13	-a	prog1 prog3
	prog23	-a	prog2 prog3

	# Pairs that checkout into world subdir.
	# Instead of using the wprog aliases, we could use "world/prog9"
	wprog12	-a	wprog1 wprog2
	wprog13	-a	wprog1 wprog3
	wprog23	-a	wprog2 wprog3


+1D.12	What does "merge" mean?

	A merge is a way of combining changes made in two independent
	copies of the same "base" file.  There are always three files
	involved in a merge: the original, or "base", file and two
	copies of that base file modified in different ways.

	Humans aren't very good at handling three things at once, so the
	terminology dealing with merges can become strained.  One way to
	think about it is that all merges are performed by inserting the
	difference between a base revision and a later revision (committed
	by someone else) into your working file.  Both the "later"
	revision and your working file are presumed to have started life
	as a copy of the "base" revision.

	In CVS, there are three main types of "merge":

	1. The "update" command automatically merges revisions committed
	   by others into your working file.  In this case, the three
	   files involved in the merge are:

		Base:    The revision you originally checked out.
		Later:   A revision committed onto the current branch
			 after you checked out the Base revision.
		Working: Your working file.  The one lying in the working
			 directory containing changes you have made.

	2. The "update -j <branch_tag>" command merges a whole branch into
	   your working file, which is presumed to be on the Main line of
	   development.

		See 4C.6

	3. The "update -j <rev> -j <rev>" merges the difference between
	   two specific revisions on some other branch (though the two
	   revisions are usually on the same branch) into your working
	   directory.

		See 4C.7




==========================================
==  Section 2	====	User Tasks    ====
==========================================

----------------
-- Section 2A --	Getting Started
----------------

 **** Questions:

 2A.1	What is the first thing I have to know?
 2A.2	Where do I work?
=2A.3	What does CVS use from my environment?
 2A.4	OK, I've been told that CVS is set up, my module is named
	"ralph" and I have to start editing.  What do I type?
 2A.5	I have been using RCS for a while.  Can I convert to CVS without
	losing my revision history?  How about converting from SCCS?


 **** Answers:

 2A.1	What is the first thing I have to know?

	Your organization has assigned one or more persons to understand,
	baby-sit and administer both the CVS programs and the data
	Repository.  I call these persons Repository Administrators.
	They will have set up a Repository and "imported" files into it.

	If you don't believe anyone has this responsibility, or you are
	just testing CVS, then *you* are the Repository Administrator.

	If you are a normal user of CVS ask your Repository Administrator
	what module you should check out.

	Then you can work.

	If you *are* the Repository Administrator, you will want to read
	everything you can get your hands on, including this FAQ.  Source
	control issues can be difficult, especially when you get to
	branches and release planning.  Expect to feel stupid for a few
	days/weeks.

	No tool in the universe avoids the need for intelligent
	organization.  In other words, there are all sorts of related
	issues you will probably have to learn.  Don't expect to dive in
	without any preparation, stuff your 300 Megabytes of sources into
	CVS and expect to start working.  If you don't prepare first, you
	will probably spend a few sleepless nights.


 2A.2	Where do I work?

	Wherever you have disk space.  That's one of the advantages of
	CVS: you use the "checkout" command to copy files from the
	Repository to your working directory, which can be anywhere you
	have the space.

	Your local group might have conventions for where to work.
	Ask your peers.


=2A.3	What does CVS use from my environment?

	You must set two environment variables.  Some shells share these
	variables with local shell variables using a different syntax.
	You'll have to learn how your shell handles them.

	Variable	Value (or action)
	---------	---------------------
	CVSROOT		Absolute pathname of the head of your Repository.

	PATH		Normally set to a list of ':'-separated directory
			pathnames searched to find executables.  You must
			make sure "cvs" is in one of the directories.
			If your CVS installation set the RCSBIN directory
			to null (""), then the RCS commands also must be
			somewhere in your PATH.


	Optional variables: (Used if set, but ignored otherwise.)

	Variable	Value (or action)
	---------	---------------------
	CVSEDITOR	The name of your favorite fast-start editor
			program.  You'll be kicked into your editor to
			supply revision comments if you don't specify them
			via -m "Log message" on the command line.
			[Note:	This is not in 1.3 -- It should appear in
				the next release.]

	EDITOR		Used if CVSEDITOR doesn't exist.  If EDITOR
			doesn't exist, CVS uses a configured constant,
			usually, "vi".

	CVSREAD		Sets files to read-only on "checkout".

	RCSBIN		Changes where CVS finds the RCS commands.

	CVSIGNORE	Adds to the ignore list.  See Section 2D.


	Other variables used by CVS that are normally set upon login:

	Variable	Value (or action)
	---------	---------------------
	LOGNAME		Used to find the real user name.

	USER		Used to find the real user name if no LOGNAME.

	HOME		Used to determine your home directory, if set.
			Otherwise LOGNAME/USER/getuid() are used to find
			your home directory from the passwd file.


 2A.4	OK, I've been told that CVS is set up, my module is named
	"ralph" and I have to start editing.  What do I type?

		cvs checkout ralph
		cd ralph

	And hack away.


 2A.5	I have been using RCS for a while.  Can I convert to CVS without
	losing my revision history?  How about converting from SCCS?

	If you are asking such questions, you are not a mere user of CVS,
	but one of its Administrators!  You should take a look at Section
	4A, "Installing CVS" and Section 4B, "Setting up and Managing
	the Repository".


----------------
-- Section 2B --	Common User Tasks
----------------

What I consider a "common user task" generally involves combinations
of the following commands:

	add, checkout, commit, diff, log, status, tag, update


Conventions in this section:

     1. Before each CVS command, you are assumed to have typed a "cd"
	command to move into a writable working directory.

     2. All further "cd" commands specified in the examples are assumed
	to start in the above working directory.

     3. Unless a point is being made about multiple instances, all modules
	are named <module>, all tags are named <tag> (branch tags are
	named <branch_tag>) and all files are named <file>.

	The checkout command will take a relative path name in place
	of a module name.  If you use a relative pathname in place of
	<module>, you should use the same relative path every place
	you see <module> in that example.


 **** Questions:

#2B.1	What is the absolute minimum I have to do to edit a file?
=2B.2	If I edit multiple files, must I type "commit" for each one?
 2B.3	How do I get rid of the directory that "checkout" created?
=2B.4	How do I find out what has changed?
=2B.5	I just created a new file.  How do I add it to the Repository?
=2B.6	How do I merge changes made by others into my working directory?
 2B.7	How do I label a set of revisions so I can retrieve them later?
 2B.8	How do I checkout an old release of a module, directory or file?
 2B.9	What do I have to remember to do periodically?


 **** Answers:


#2B.1	What is the absolute minimum I have to do to edit a file?

	Tell your Repository Administrator to create a module covering the
	directory or files you care about.  You'll find out that the
	module name is named <module>.  Then type:

		cvs checkout <module>
		cd <module>
		emacs <file>	      # Isn't Emacs a synonym for editor?
		cvs commit <file>

	If you don't use modules (in my opinion, a mistake), you can check
	out a directory by substituting its relative path within the
	Repository for <module> in the example above.

	To check out a single file, you'll have to change the "cd
	<module>" to "cd to the parent of the file named in <module>".


=2B.2	If I edit multiple files, must I type "commit" for each one?

	No.  You can do them all at once by name or by directory.
	See 3D.2.


 2B.3	How do I get rid of the directory that "checkout" created?

	Change your directory to be the same as when you executed the
	"checkout" command and type:

		cvs release -d <module>


	The current version of CVS does not detect foreign directories
	(i.e. ones that weren't created by CVS) in your working
	directory and will destroy them.

	If you don't care about keeping "history", and you don't care to
	plan ahead to a more completely implemented "release" command, you
	can just remove it.  That's "rm -rf <module>" under Unix.


=2B.4	How do I find out what has changed?

	There are many ways to answer this.

	To find out what you've changed in your current working directory
	since your last commit, type:

		cvs diff

	To find out what other people have added (to your branch) since
	you last checked out or updated, type:

		cvs diff -r BASE -r HEAD

	To look at a revision history containing the comments for all
	changes, you can use the "log" command.

	You can also use "history" to trace a wide variety of events.


=2B.5	I just created a new file.  How do I add it to the Repository?

	The "update" command will display files CVS doesn't know about in
	your working directory marked with a '?' indicator.

		? <file>

	To add <file> to the Repository, type:

		cvs add <file>
		cvs commit <file>


=2B.6	How do I merge changes made by others into my working directory?

	If you are asking about other branches, see Section 4C on
	"Branching".  You will have to use the "update -j" command.

	Retrieving changes made to the Repository on the *same* branch you
	are working on is the main purpose of the "update" command.  The
	"update" command tries to merge work committed to the Repository
	by others since you last executed "checkout", "update" or "commit"
	into your working files.

	For a single file, there are five possible results when you type
	the "update" command:

	1. If neither you nor others have made changes to <file>, "update"
	   will print nothing.

	2. If you have made no changes to a file, but others have, CVS
	   will replace your working file with a copy of the latest
	   revision of that file in the Repository.  You will see:

		U <file>

	   You might want to examine the changes (using the CVS "diff"
	   command) to see if they mesh with your own in related files.

	3. If you have made changes, but others have not, you will see:

		M <file>

	   Nothing happened except you were told that you have a modified
	   file in your directory.

	4. If both you and others have made changes to a file, but in
	   different sections of the file, CVS will merge the changes
	   stored in the Repository since your last "checkout", "update"
	   or "commit" into your working file.  You will see:

		RCS file: /Repository/module/<file>
		retrieving revision 1.X
		retrieving revision 1.Y
		Merging differences between 1.X and 1.Y into <file>
		M <file>

	   If you execute "diff" before and after this step, you should
	   see the same output.  This is one of the few times the
	   otherwise nonsensical phrase "same difference" means something.


	5. If both you and others have made changes to the same section of
	   a file, CVS will merge the changes into your file as in #4
	   above, but it will leave conflict indicators in the file.
	   You will see:

		RCS file: /Repository/module/<file>
		retrieving revision 1.X
		retrieving revision 1.Y
		Merging differences between 1.X and 1.Y into <file>
		rcsmerge warning: overlaps during merge
		cvs update: conflicts found in <file>
		C <file>

	   This is a "conflict".  The file will contain strange-looking
	   text marking the overlapping text.

	   You must examine the overlaps with care and resolve the
	   problem without removing all previous work.



 2B.7	How do I label a set of revisions so I can retrieve them later?

	To "tag" the BASE revisions (the ones you last checked out,
	updated, or committed) you should "cd" to the head of the working
	directory you want to tag and type:

		cvs tag <tag>

	It recursively walks through your working directory tagging the
	BASE revisions of all files.

	To "tag" the latest revision on the Main branch in the
	Repository, you can use the following from anywhere:
	(No "cd" is required -- it works directly on the Repository.)

		cvs rtag <tag> <module>


 2B.8	How do I checkout an old release of a module, directory or file?

	Module names and directories are simply ways to name sets of
	files.  Once the names are determined, there are 6 ways to specify
	which revision of a particular file to check out:

	1. By tag or symbolic name, via the "-r <tag>" option.

	2. By date, via the "-D <date>" option.

	3. By branch tag (a type of tag with a magic format), via the
	   "-r <branch_tag>" option.

	4. By date within a branch, via the "-r <branch_tag>:<date>"
	   option.

	5. By an explicit branch revision number, which refers to the
	   latest revision on the branch.  This isn't really an "old"
	   revision, from the branch's perspective, but from the user's
	   perspective the branch might have been abandoned in the past.

	6. An explicit revision number.  Though this works, it is almost
	   useless for more than one file.


	You type:

		cvs checkout <option-specified-above> <module>
		cd <module>


 2B.9	What do I have to remember to do periodically?

	You should execute "cvs -n update" fairly often to keep track of
	what you and others have changed.  It won't change anything -- it
	will just give you a report.

	Unless you are purposely delaying the inclusion of others' work,
	you should execute "update" once in a while and resolve the
	conflicts.  It is not good to get too far out of sync.

	It is assumed that your system administrators have arranged for
	editor backup and Unix temp files (#* and .#*) to be deleted after
	a few weeks.  But you might want to look around for anything else
	that is ignored or hidden.  Try "cvs -n update -I !" to see all
	the ignored files.

	If you are the Repository Administrator, see 4B.17.


----------------
-- Section 2C --	Less Common User Tasks
----------------

What I consider a "less common user task" generally involves one or
more of the following commands:

	history, import, export, rdiff, release, remove, rtag


 **** Questions:

 2C.1	Can I create sub-directories in my working directory?
 2C.2	How do I add new sub-directories to the Repository?
 2C.3	How do I remove a file I don't need?
=2C.4	How do I rename a file?
 2C.5	How do I make sure that all the files and directories in my
	working directory are really in the Repository?
=2C.6	How do I create a branch?
=2C.7	How do I modify the modules file?  How about the other files in
	the CVSROOT administrative area?
+2C.8	How do I split a file into pieces, retaining revision histories?


 **** Answers:


 2C.1	Can I create sub-directories in my working directory?

	Yes, but the "update" command will traverse them, wasting a lot
	of time.  You can't currently ignore directories but if a
	directory has no ./CVS administrative directory, nothing will
	happen to it during an "update".

	On the other hand "release -d" will delete it without warning.


 2C.2	How do I add new sub-directories to the Repository?

	The "add" command will work on directories.  You type:

	    mkdir <dir>
	    cvs add <dir>

	It will respond:

	    Add directory /Repos/<dir> to the Repository (y/n) [n] ?

	If you type a 'y', you will create both a directory in the
	Repository and a ./CVS administrative directory within the local
	<dir> directory.


 2C.3	How do I remove a file I don't need?

	(See the questions in Section 4B on removing files from the
	 Repository.)

	You type:

		rm <file>
		cvs remove <file>

	CVS registers the file for removal.  To complete the removal, you
	must type:

		cvs commit <file>

	CVS moves the file to the Attic associated with your working
	directory.  Each directory in the Repository stores its deleted
	files in an Attic sub-directory.  A normal "checkout" doesn't
	look in the Attic, but if you specify a tag, a date or a
	revision, the "checkout" (or "update") command will retrieve
	files from the Attic with that tag, date or revision.


=2C.4	How do I rename a file?

	CVS does not offer a way to rename a file in a way that CVS can
	track later.  See Section 4B for more information.

	Here is the best way to get the effect of renaming, while
	preserving the change log:

	   1. Copy the RCS (",v") file directly in the Repository.

		cp $CVSROOT/<odir>/<ofile>,v $CVSROOT/<ndir>/<nfile>,v

	   2. Remove the old file using CVS.

	      By duplicating the file, you will preserve the change
	      history and the ability to retrieve earlier revisions of the
	      old file via the "-r <tag/rev>" or "-D <date>" options to
	      "checkout" and "update".

		cd <working-dir>/<odir>
		rm <ofile>
		cvs remove <ofile>
		cvs commit <ofile>

	   3. Retrieve <newfile> and remove all the Tags from it.

	      By stripping off all the old Tags, the "checkout -r" and
	      "update -r" commands won't retrieve revisions Tagged before
	      the renaming.

		cd <working-dir>/<ndir>
		cvs update <nfile>
		cvs log <nfile>			# Save the list of Tags
		cvs tag -d <tag1> <nfile>
		cvs tag -d <tag2> <nfile>
		. . .


	This technique can be used to rename files within one directory or
	across different directories.  You can apply this idea to
	directories too, as long as you apply the above to each file and
	don't delete the old directory.

	Of course, you have to change the build system (e.g. Makefile) in
	your <working-dir> to know about the name change.


 2C.5	How do I make sure that all the files and directories in my
	working directory are really in the Repository?

	Normally, you only need to be notified of files you forgot to
	"add".  A simple "update", or "cvs -n update" (which won't modify
	your working directory) will display non-added files preceded by a
	'?'  indicator.  To recover, "add" and "commit" them.

	To verify that all your directories are in the Repository, you
	have to go look.  Though CVS traverses all directories, it
	produces no output for directories not backed up by a Repository
	directory.

	By default many patterns of files are ignored.  If you create a
	file named "core" or a file ending in ".o", it is usually
	ignored.  If you really want to see all the files that aren't in
	the Repository, you can use a special "ignore" pattern to say
	"ignore no files".  Try executing: (You may have to quote or
	backwhack (i.e. precede by '\') the '!' in your shell.)

		cvs -n update -I !

	The above command will display not only the normal 'M'odified,
	'U'pdate and 'C'onflict indicators on files within the
	Repository, but it will also display each file not in the
	Repository preceded by a '?' character.

	The '-n' option will not allow "update" to alter your working
	directory.


=2C.6	How do I create a branch?

	Type this in your working directory:

		cvs tag -b <branch_tag>

	and you will create a branch.  No files have real branches in them
	yet, but if you move onto the branch by typing:

		cvs update -r <branch_tag>

	and commit a file in the normal way:

		cvs commit <file>

	then a branch will be created in the underlying <file>,v file and
	the new revision of <file> will appear only on that branch.

	See Section 4C, on Branching.


=2C.7	How do I modify the modules file?  How about the other files in
	the CVSROOT administrative area?

	A module named "modules" has been provided in the default modules
	file, so you can type:

		cvs checkout modules
		cd modules

	Another module named CVSROOT has been provided in the default
	modules file, covering all the administrative files.  Type:

		cvs checkout CVSROOT
		cd CVSROOT

	Then you can edit your files, followed by:

		cvs commit

	If you use the provided template for the "modules" file, both the
	CVSROOT and the "modules" module will have the "mkmodules" program
	as a "commit helper".

	After a file is committed in these modules the "mkmodules"
	command will convert all the files CVSROOT directory within the
	Repository into a form that is usable by CVS.


+2C.8	How do I split a file into pieces, retaining revision histories?

	If you and a coworker find yourselves repeatedly committing the
	same file, but never for changes in the same area of the file, you
	might want to split the file into two or more pieces.  If you are
	both changing the same section of code, splitting the file is of
	no use.  You should talk to each other instead.

	If you decide to split the file, here's a suggestion.  In many
	ways, it is similar to multiple "renamings" as described in
	2C.4 above.

	Say you want to split <fileA>, which already in the Repository,
	into three pieces, <fileA>, <fileB> and <fileC>.

	   1. Copy the RCS (",v") files directly in the Repository,
	      creating all the new files.

		cp $CVSROOT/<path>/<fileA>,v $CVSROOT/<path>/<fileB>,v
		cp $CVSROOT/<path>/<fileA>,v $CVSROOT/<path>/<fileC>,v
		cvs update <fileB> <fileC>

	   2. Then remove all the <tags> from the new files by using:

		cvs log <fileB> <fileC>	      # Save the list of <tag?>
		cvs tag -d <tag1> <fileB> <fileC>
		cvs tag -d <tag2> <fileB> <fileC>
		. . .

	   3. Edit and commit all three copies of the same file into three
	      distinct files.  This is a hand-editing job, not something
	      CVS can handle.  [From experience, I'd suggest making sure
	      that only one copy of each line of code exists among the
	      three files, except for "include" statements, which must be
	      duplicated.  And make sure the code compiles.]

		emacs <fileA> <fileB> <fileC>
		cvs commit <fileA> <fileB> <fileC>


	As in the "rename" case, by duplicating the files, you'll preserve
	the change history and the ability to retrieve earlier revisions.

	Also, as in the "rename" case, you can apply this idea to
	directories too, by changing <path> to <pathA>, <pathB> and
	<pathC> in the example.

	Of course, you have to change your build system (e.g. Makefile).



----------------
-- Section 2D --	General Questions
----------------

 **** Questions:

=2D.1	How do I see what CVS is trying to do?
 2D.2	If I work with multiple modules, should I check them all out and
	commit them occasionally?  Is it OK to leave modules checked out?
 2D.3	What is a "sticky" tag? What makes it sticky? How do I loosen it?
 2D.4	How do I get an old revision without updating the "sticky tag"?
=2D.5	What operations disregard sticky tags?
=2D.6	Is there a way to avoid reverting my Emacs buffer after
	committing a file?  Is there a "cvs-mode" for Emacs?
 2D.7	How does conflict resolution work?  What *really* happens if two
	of us change the same file?
 2D.8	How can I tell who has a module checked out?
#2D.9	Where did the .#<file>.1.3 file in my working directory come from?
 2D.10	What is this "ignore" stuff?
 2D.11	Why does .cvsignore not ignore directories?
 2D.12	Is it safe to interrupt CVS using Control-C?
 2D.13	How do I turn off the "admin" command?
 2D.14	How do I turn off the ability to disable history via "cvs -l"?
 2D.15	How do I keep certain people from accessing certain directories?


 **** Answers:


=2D.1	How do I see what CVS is trying to do?

	The '-t' option on the main "cvs" command will display every
	external command (mostly RCS commands and file deletions) it
	executes.  When combined with the '-n' option, which prevents the
	execution of any command that might modify a file, you can see
	what it will do before you let it fly.  The '-t' option will *not*
	display every internal action, only calls to external programs.

	To see a harmless example, try typing:

		cvs -nt update

	Some systems offer a "trace" command that will display all system
	calls as they happen.  This is a *very* low-level interface, but
	it can be useful.

	The most complete answer is to read the source, compile it
	with the '-g' option and execute it under a debugger.


 2D.2	If I work with multiple modules, should I check them all out and
	commit them occasionally?  Is it OK to leave modules checked out?

	The simple answers are "Yes."

	There is no reason to remove working directories, other than to
	save disk space.  As long as you have committed the files you
	choose to make public, your working directory is just like any
	other directory.

	CVS doesn't care whether you leave modules checked out or not.
	The advantage of leaving them checked out is that you can quickly
	visit them to make and commit changes.


 2D.3	What is a "sticky" tag? What makes it sticky? How do I loosen it?

	When you execute "update -r <tag>", CVS remembers the <tag>.  It
	has become "sticky" in the sense that until you change it or
	remove it, the tag is remembered and used in references to the
	file as if you had typed "-r <tag>" on the command line.

	It is most useful for a <branch_tag>, which is a sticky tag
	indicating what branch you are working on.

	A revision number ("-r <rev-number>") or date ("-D <date>") can
	also become sticky when they are specified on the command line.

	A sticky tag, revision or date remains until you specify another
	tag, revision or date the same way.  The "update -A" command
	moves back to the Main branch, which has the side-effect of
	clearing all sticky items on the updated files.

	The "checkout" command creates sticky tags, revisions and dates
	the same way "update" does.

	Also, the '-k' option records a "sticky" keyword option that
	is used in further "updates until "update -A" is specified.


 2D.4	How do I get an old revision without updating the "sticky tag"?

	Use the '-p' option to "pipe" data to standard output.  The
	command "update -p -r <tag/rev>" sends the selected revision to
	your standard output (usually the terminal, unless redirected).
	The '-p' affects no disk files, leaving a "sticky tag" unaltered
	and avoiding all other side-effects of a normal "update".

	If you want to save the result, you can redirect "stdout" to a
	file using your shell's redirection capability.  In most shells
	the following command works:

	    cvs update -p -r <tag/rev> filename > diskfile


=2D.5	What operations disregard sticky tags?

	The functions that routinely disregard sticky tags are:

	     1. Those that work directly on the Repository or its
		administrative files:

		admin	rtag	log	status	remove	history

	     2. Those that take Tags or revisions as arguments and ignore
		everything else: (They also never *set* a sticky tag.)

		rdiff	import	export

	     3. The "release" command itself ignores sticky tags, but it
		calls "cvs -n update" (which *does* pay attention to a
		sticky tag) to figure out what inconsistencies exist in
		the working directory.  If no discrepancies exist between
		the files you originally checked out (possibly marked by a
		sticky tag) and what is there now, "release -d" will
		delete them all.

	     4. The "tag" command, which works on the revision lying in
		the working directory however it got there.  That the
		revision lying there might happen to have a sticky tag
		attached to it is not the "tag" command's concern.


	The main function that *does* read and write sticky tags is the
	"update" command.  You can avoid referring to or changing the
	sticky tag by using the '-p' option, which sends files to your
	terminal, touching nothing else.

	The "checkout" command sets sticky tags when checking out a new
	module and it acts like "update" when checking out a module into
	an existing directory.

	The "diff" and "commit" commands use the sticky tags, unless
	overridden on the command line.  They do not set sticky tags.  (In
	the future, "commit" might set a sticky branch tag on a newly
	added file.)  Note that you can only "commit" to a file checked
	out with a sticky tag, if the tag identifies a branch.

	There are really two types of sticky tags, one attached to
	individual files (in the ./CVS/Entries file) and one attached to
	each directory (in the ./CVS/Tag file).  They can differ.

	The "add" command doesn't pay attention to anything -- it just
	registers the desire to add a new file.  When a newly added file
	is `committed", CVS *should* use the "directory tag" to determine
	what branch to commit it to and set the corresponding sticky tag.
	Unfortunately, it doesn't work correctly in CVS 1.3.  See 4C.8.


=2D.6	Is there a way to avoid reverting my Emacs buffer after
	committing a file?  Is there a "cvs-mode" for Emacs?

	See Section 4F.1


 2D.7	How does conflict resolution work?  What *really* happens if two
	of us change the same file?

	While editing files, there is no conflict.  You are working on
	separate virtual branches of development contained in your working
	directories.  When one of you decides to commit the file, the
	other may not commit the same file until "update" has merged the
	two together.

	Say you both check out rev 1.2 of <file>.  Your coworker commits
	revision 1.3.  When you try to commit your file, CVS says:

		cvs commit: Up-to-date check failed for `<file>'

	You must merge your coworker's changes into your working file by
	typing:

		cvs update <file>

	which will produce the output described in 2B.6.

	After you resolve any overlaps caused by the merging process, you
	may then commit the file.

	Yes, the first one who commits can cause the other some work.

	Yes, between the time you execute "update" and "commit", someone
	else may have committed a later revision of <file>.  You will have
	to execute "update" again to merge the new work before
	committing.  Most organizations don't have this problem.  If you
	do, you might consider splitting the file.


 2D.8	How can I tell who has a module checked out?

	If you "checkout" module names (not relative pathnames) and you
	use the release command, the "history" command will display who
	has what checked out.  It is advisory only; it can be circumvented
	by using the '-l' option on the main "cvs" command.


#2D.9	Where did the .#<file>.1.3 file in my working directory come from?

	It was created during an "update" when CVS merged changes from the
	Repository into your modified working file.

	It serves the same purpose as any "backup" file: saving your bacon
	often enough to be worth retaining.  It is invaluable in
	recovering when things go wrong.

	Say Developers A (you) and B check out rev 1.3 of file <file>.
	You both make changes -- different changes.  B commits first, so
	<file>,v in the Repository contains revisions up through 1.4.

	At this point, there are 5 (yes, five) versions of the file of
	interest to you:

	1. Revision 1.3		   (What you originally checked out.)
	2. Revision 1.4		   (What you need from developer B.)
	3. Your old working file.  (Before the update.)
	4. Your new working file.  (After the merge caused by "update".)
	5. Revision 1.5		   (Which you will commit shortly.)

	In the case where your working file was not modified, #1 and #3
	will be the same, as will #2 and #4.  In this degenerate case,
	there is no need to create #5.  The following assumes that your
	working file was modified.

	If the merge executed by the "update" caused no overlaps, #4
	and #5 will be the same.  But you might then make changes before
	committing, so the difference between #4 and #5 might be more
	than just the correction of overlaps.  In general, though, you
	don't need #4 after a commit.

	But #3 (which is the one saved as ".#<file>.1.3") holds all of
	your work, independent of B's work.  It could represent a major
	effort that you couldn't afford to lose.  If you don't save it
	somewhere, the merge makes #3 *disappear* under a potential
	rat's nest of conflicts caused by overlapping changes.

	I have been saved a few times, and others I support have been
	saved hundreds of times, by the ability to "diff <original file>
	<original file with only my work added>", which can be done in the
	example above by the Unix shell command:

		cvs update -p -r 1.3 <file> | diff - .#<file>.1.3

	The assumption is that the ".#" files will be useful far beyond
	the "commit" point, but not forever.  You are expected to run
	the "normal" Unix cleanup script from "cron", which removes "#*"
	and ".#*" files older than a some period chosen by your
	sysadmin, usually ranging from 7 to 30 days.

	A question was raised about the need for #3 after #5 has been
	committed, under the assumption that you won't commit files until
	everything is exactly as you like them.

	This assumes perfect humans, which violates one of the Cardinal
	rules of Software Engineering: Never assume any form of discipline
	on the part of the users of software.  If restrictions are not
	bound into the software, then you, the toolsmith, have to arrange
	a recovery path.

	In other words, I've seen every possible variety of screwup you
	can imagine in #5.  There is no way to make assumptions about
	what "should" happen.  I've seen #5 filled with zeros because of
	NFS failures, I've seen emacs core dumps that leave #5 in an
	unreasonable state, I've seen a foolish developer uppercase the
	whole file (with his "undo" size set low so he couldn't undo it)
	and decide that it would be less work to play with the
	uppercased file than to blow it away and start over.  I've even
	seen committed files with conflict markers still in them.

	There are all sorts of scenarios where having #3 is incredibly
	useful.  You can move it back into place and try again.


 2D.10	What is this "ignore" stuff?

	The "update" and "import" commands use collections of Unix
	wildcards to skip over files matching any of those patterns.

	You may add to the built-in ignore list by adding wildcards to
	the following places:  (They are read in this order.)

	1. In a file named "cvsignore" in $CVSROOT/CVSROOT.

	   A Repository Administrator uses this to add site-specific
	   files and patterns to the built-in ignore list.

	2. In a file named ".cvsignore" in your home directory.

	   For user-specific files.  For example, if you use "__" as
	   your default junk file prefix, you can put "__*" in your
	   .cvsignore file.

	   People who play around in the X tree might want to put
	   "Makefile" in their ignore list, since they are all
	   generated and usually don't end up in the Repository.

	3. In the CVSIGNORE environment variable.

	   For session-specific files.

	4. Via the '-I' option on "import" or "update" commands.

	   For this-command-only files.

	5. In a file named ".cvsignore" within each directory.

	   The contents of a ".cvsignore" file in each directory is
	   temporarily added to the ignore list.  This way you can ignore
	   files that are peculiar to that directory, such as executables
	   and other files without known suffix patterns.

	In any of the 5 places listed above, a single '!' character nulls
	out the ignore list.  A Repository administrator can use this to
	override, rather than enhance, the built-in ignore list.  A user
	can choose to override the system-wide ignore list.  For example,
	if you place "! *.o *.a" in your .cvsignore file, only *.o *.a
	files, plus any files a local-directory .cvsignore file, are
	ignored.


 2D.11	Why does .cvsignore not ignore directories?

	Ignore lists are intended to be per-directory wildcards matching
	various patterns.  They are matched against file names, not
	directory names or relative paths ('/' is an invalid character in
	an ignore list).  I suppose it could be extended, but as it
	stands, it only works on files.

	This might change in the future.


 2D.12	Is it safe to interrupt CVS using Control-C?

	It depends on what you mean by "safe".  ("Ah," said Arthur,
	"this is obviously some strange usage of the word *safe* that I
	wasn't previously aware of." -- Hitchhiker's Guide to the Galaxy)

	You won't hurt the underlying RCS files and if you are executing a
	command that only *reads* data, you will have no cleanup to do.

	But you may have to hit Control-C repeatedly to stop it.  CVS uses
	the Unix "system" routine which blocks signals in the CVS parent
	process.  A single Control-C during "system" will only halt the
	child process, usually some form of RCS command.

	If you don't hit another Control-C while the CVS process has
	control, it is likely to continue onto the next task assuming that
	the earlier one did its job.  It is not enough to hit two
	Control-C's.  You might simply kill two child processes and not
	interrupt CVS at all.  Depending on the speed of your processor,
	your terminal and your fingers, you might have to hit dozens of
	Control-C's to stop the damn thing.


	Executing a CVS command, such as "commit" or "tag" that writes
	to the files is a different matter.

	Since CVS is not a full-fledged database, with what database
	people call "commit points", merely stopping the process will
	not place you back in the starting blocks.  CVS has no concept of
	an "atomic" transaction or of "backtracking", which means that
	a command can be half-executed.

	First, you will usually leave lock files that you have to go clean
	up in the Repository.

	Example1:

		If you interrupt a multi-file "commit" in the middle of
		an RCS checkin, RCS will leave the file either fully
		checked-in or in its original state.  But CVS might have
		been half-way through the list of files to commit.  The
		directory or module will be inconsistent.

		To recover, you must remove the lock files, then decide
		whether you want to back out or finish the job.

		To back out, you'll have to apply the "admin -o"
		command, very carefully, to remove the newly committed
		revisions.  This is usually a bad idea, but is
		occasionally necessary.

		To finish, you can simply retype the same commit command.
		CVS will figure out what files are still modified and
		commit them.  It helps that RCS doesn't leave a file in an
		intermediate state.


	Example2:

		If you interrupt a multi-file "tag" command, you have a
		problem similar, but not equivalent, to interrupting a
		"commit".  The RCS file will still be consistent, but
		unlike "commit", which only *adds* to the RCS file, "tag"
		can *move* a tag and it doesn't keep a history of what
		revision a tag used to be attached to.

		Normally, you have little choice but to re-execute the
		command and allow it to tag everything consistently.

		You might be able to recover by applying a raw "rcs -n" to
		the Repository, or by using the equivalent: "cvs admin".


	Halting a new "checkout" should cause no harm.  If you don't want
	it, "release" (or rm -rf) it.  If you do want it, re-execute the
	command.

	Halting "update" half-way will give you some strange collection
	of files and revisions.  You'll have to examine the output from
	the command and take a look at each file that was modified.  Good
	Luck.



 2D.13	How do I turn off the "admin" command?

	In the current revision, you'd have to edit the source code.


 2D.14	How do I turn off the ability to disable history via "cvs -l"?

	In the current revision, you'd have to edit the source code.


 2D.15	How do I keep certain people from accessing certain directories?

	If you don't try to run CVS set[ug]id, you can use Unix groups and
	permissions to limit access to the Repository.

	If you only want to limit "commit" commands, you can write a
	program to put in the "commitinfo" file.  In the "contrib"
	directory, there is a script called "cvs_acls.pl" that implements
	a form of access control.


========================================
==  Section 3	====	Commands    ====
========================================

This section contains questions that are easily recognized to be about a
single command, usually of the form: "Why does the 'xyz' command do this?"

Questions about "missing" features and side-effects not attributable to a
particular command are in Section 2D, "General Questions".

I won't provide patches here that are longer than a few lines.  Patches
referred to in this section are available in the FTP archive described
toward the beginning of this document.


----------------
-- Section 3A --	"add", "ad", "new"
----------------

 **** Questions:

 3A.1	What is "add" for?
 3A.2	How do I add a new file to the branch I'm working on?
 3A.3	Why did my newly added file end up in the Attic?
 3A.4	How do I put a new file on the Main Branch and branch off from
	there onto my default branch?


 **** Answers:

 3A.1	What is "add" for?

	To add a new directory to the Repository or to register the
	desire to add a new file to the Repository.

	The directory is created immediately, after verification, while
	the desire to add the file is recorded in the local ./CVS
	administrative directory.  To really add the file to the
	Repository, you must then "commit" it.


 3A.2	How do I add a new file to the branch I'm working on?

	See 4C.8


 3A.3	Why did my newly added file end up in the Attic?

	Your new file is placed in the Attic if it is added onto a side
	branch without ever showing up on the trunk.

	If the file were in the main Repository area, it would show up
	when the Main branch is checked out.  You didn't commit it onto
	the Main branch -- only onto the side branch.


 3A.4	How do I put a new file on the Main Branch and branch off from
	there onto my default branch?

	See 4C.8



----------------
-- Section 3B --	"admin", "adm", "rcs"
----------------

 **** Questions:

 3B.1	What is "admin" for?
 3B.2	Wow!  Isn't that dangerous?
=3B.3	What would I normally use "admin" for?
=3B.4	What should I avoid when using "admin"?
-3B.5	How do I restrict the "admin" command?  The -i flag in the modules
	file can restrict commits.  What's the equivalent for "admin"?
+3B.6	I backed out a revision with "admin -o" and committed a
	replacement.  Why doesn't "update" retrieve the new revision?


 **** Answers:


 3B.1	What is "admin" for?

	To provide direct access to the underlying "rcs" command, which
	is not documented in this FAQ


 3B.2	Wow!  Isn't that dangerous?

	Yes.

	Though you can't hurt the internal structure of an RCS file using
	its own "rcs" command, you *can* change the underlying RCS
	files using "admin" in ways that CVS can't handle.

	If you feel the need to use "admin", create some test files
	with the RCS "ci" command and experiment on them with "rcs"
	before blasting any CVS files.


=3B.3	What would I normally use "admin" for?

	Normally, you wouldn't use admin at all.  In unusual
	circumstances, experts can use it to set up or restore the
	internal RCS state that CVS requires.

	You can also use the '-o' (for "outdate") option to remove
	revisions you don't care about.  This has its own problems, such
	as leaving dangling Tags and confusing the "update" command.


=3B.4	What should I avoid when using "admin"?

	Never use "admin" to alter branches (using the '-b' option), which
	CVS takes very seriously.  If you change the default branch, CVS
	will not work as expected.  If you create new branches without
	using the "tag -b" command, you may not be able to treat them as
	CVS branches.

	Don't try to use the '-l' option, which will lock RCS files.
	See 4D.7 for a cautionary scenario.

	The "admin -o <file>" allows you to delete revisions, usually a
	bad idea.  You should commit a correction rather than back out a
	revision.  Outdating a revision is prone to all sorts of problems:

	1. Discarding data is always a bad idea.  Unless something in the
	   revision you just committed is a threat to your job or your
	   life, (like naming a function "<boss's name>_is_a_dweeb", or
	   including the combination to the local Mafioso's safe in a C
	   comment), just leave it there.  No one cares about simple
	   mistakes -- just commit a corrected revision.

	2. The time travel paradoxes you can cause by changing history
	   are not worth the trouble.  Even if CVS can't interfere with
	   your parents' introduction, it *can* log commits in at least
	   two ways (history and loginfo).  The reports now lie -- the
	   revision referred to in the logs no longer exists.

	3. If you used "import" to place <file> into CVS, outdating all
	   the revisions on the Main branch back to and including revision
	   1.2 (or worse, 1.1), will produce an invalid CVS file.

	   If the <file>,v file only contains revision 1.1 (and the
	   connected branch revision 1.1.1.1), then the default branch
	   must be set to the Vendor branch as it was when you first
	   imported the file.  Outdating back through 1.2 doesn't restore
	   the branch setting.  Despite the above admonition against it,
	   "admin -b" is the only way to recover:

		cvs admin -b1.1.1 <file>

	4. Although you can't outdate a physical (RCS) branch point
	   without removing the whole branch, you *can* outdate a revision
	   referred to by a magic branch tag.  If you do so, you will
	   invalidate the branch.

	5. If you "outdate" a tagged revision, you will invalidate all
	   uses of the <tag>, not just the one on <file>.  A tag is
	   supposed to be attached to a consistent set of files, usually a
	   set built as a unit.  By discarding one of the files in the
	   set, you have destroyed the utility of the <tag>.  And it
	   leaves a dangling tag, which points to nothing.

	6. And even worse, if you commit a revision already tagged, you
	   will alter what the <tag> pointed to without using the "tag"
	   command.  For example, if revision 1.3 has <tag> attached to it
	   and you "outdate" the 1.3 revision, <tag> will point to a
	   nonexistent revision.  Although this is annoying, it is nowhere
	   near as much trouble as the problem that will occur when you
	   commit to this file again, recreating revision 1.3.  The old
	   tag will point to the new revision, a file that was not in
	   existence when the <tag> was applied.  And the discrepancy is
	   nearly undetectable.


	If you don't understand the above, you should not use the admin
	command at all.


-3B.5	How do I restrict the "admin" command?  The -i flag in the modules
	file can restrict commits.  What's the equivalent for "admin"?

	At this writing, to disable the "admin" command, you will have
	to change the program source code, recompile and reinstall.


+3B.6	I backed out a revision with "admin -o" and committed a
	replacement.  Why doesn't "update" retrieve the new revision?
	   
	CVS is confused because the revision in the ./CVS/Entries file
	matches the latest revision in the Repository *and* the timestamp
	in the ./CVS/Entries file matches your working file.  CVS believes
	that your file is "up-to-date" and doesn't need to be updated.

	You can cause CVS to notice the change by "touch"ing the file.
	Unfortunately what CVS will tell you is that you have a "Modified"
	file.  If you then "commit" the file, you will bypass the
	normal CVS check for "up-to-date" and will probably commit the
	revision that was originally removed by "admin -o".

	Changing a file without changing the revision number confuses CVS
	no matter whether you did it by replacing the revision (using
	"admin -o" and "commit" or raw RCS commands) or by applying an
	editor directly to a Repository (",v") file.  Don't do it unless
	you are absolutely certain no one has the latest revision of the
	file checked out.

	The best solution to this is to institute a program of deterrent
	flogging of abusers of "admin -o".

	The "admin" command has other problems."  See 3B.4 above.


----------------
-- Section 3C --	"checkout", "co", "get"
----------------

 **** Questions:

 3C.1	What is "checkout" for?
 3C.2	What is the "module" that "checkout" takes on the command line?
 3C.3	Isn't a CVS "checkout" just a bunch of RCS checkouts?
 3C.4	What's the difference between "update" and "checkout"?
 3C.5	Why can't I check out a file from within my working directory?
 3C.6	How do I avoid dealing with those long relative pathnames?
 3C.7	Can I move a checked-out directory?  Does CVS remember where it
	was checked out?
#3C.8	How can I lock files on checkout the way RCS does?
+3C.9	What is "checkout -s"?  How is it different from "checkout -c"?


 **** Answers:

 3C.1	What is "checkout" for?

	To acquire a copy of a module (or set of files) to work on.

	All work on files controlled by CVS starts with a "checkout".


 3C.2	What is the "module" that "checkout" takes on the command line?

	It is a name for a directory or a collection of files in the
	Repository.  It provides a compact name space and the ability to
	execute before and after helper functions based on definitions in
	the modules file.

	See 1D.11.


 3C.3	Isn't a CVS "checkout" just a bunch of RCS checkouts?

	Like much of CVS, a similar RCS concept is used to support a CVS
	function.  But a CVS checkout is *not* the same as an RCS
	checkout.

	Differences include:

	1. CVS does not lock the files.  Others may access them at the
	   same time.

	2. CVS works best when you provide a name for a collection of
	   files (a module or a directory) rather than an explicit list of
	   files to work on.

	3. CVS remembers what revisions you checked out and what branch
	   you are on, simplifying later commands.



 3C.4	What's the difference between "update" and "checkout"?

	The "checkout" and "update" differ in the following ways:

	1. The "checkout" command always creates a directory, moves into
	   it, then becomes equivalent to "update -d".

	2. The "update" does not create directories unless you add the
	   '-d' option.

	3. "Update" is intended to be executed within a working directory
	   created by "checkout".  It doesn't take a "module" or
	   "directory" argument, but figures out what Repository files to
	   look at by reading the ./CVS administrative directory.

	4. The two commands generate completely different types of records
	   in the "history" file.

	The two commands are equivalent in nearly all other respects.


 3C.5	Why can't I check out a file from within my working directory?

	You normally check out a module or directory, not a file.  And you
	normally do it only once at the beginning of a project.

	After the initial "checkout", you can use the "update" command
	to retrieve any file you want within the checked-out directory.
	There is no need for further "checkout" commands.

	If you want to retrieve another module or directory to work on,
	you must provide names for both where to find it in the Repository
	and where to put it on disk.  The "modules" file and your
	current directory supply two pieces of naming information.  While
	inside a checked-out working directory, the CVS administrative
	information provides most of the rest.

	You should be careful not to confuse CVS with RCS and use
	"checkout" in the RCS sense.  An RCS "checkout" (which is
	performed by the RCS "co" command) is closer to a "cvs update"
	than to a "cvs checkout".


 3C.6	How do I avoid dealing with those long relative pathnames?

	This question has also been phrased:

	    How do I avoid all those layers of directories on checkout?
	or
	    Why do I have to go to the top of my working directory and
	    checkout some long pathname to get a file or two?


	This type of question occurs only among groups of people who
	decide not to use "modules".  The answer is to use "module".

	When you hand the "checkout" command a relative pathname, rather
	than a module name, all directories in the path are created,
	maintaining the same directory hierarchy as in the Repository.
	The same kind of environment results if you specify a "module"
	that is really an alias expanding into a list of relative
	pathnames rather than a list of module names.

	If you use "module" names, "checkout" creates a single
	directory by the name of the module in your current directory.
	This "module" directory becomes your working directory.

	The "module" concept combines the ability to "name" a collection
	of files with the ability to structure the Repository so that
	consistent sets of files are checked out together.  It is the
	responsibility of the Repository Administrators to set up a
	modules file that describes the software within the Repository.

	I consider it unfortunate that CVS sprouted the ability to check
	out relative pathnames without more extensive and flexible
	support for "modules."


 3C.7	Can I move a checked-out directory?  Does CVS remember where it
	was checked out?

	Yes and Yes.

	The ./CVS/Repository file in each working directory contains a
	pathname pointing to the matching directory within the
	Repository.  The pathname is either absolute or relative to
	$CVSROOT, depending on how you configured CVS.

	When you move a checked-out directory, the CVS administrative
	files will move along with it.  As long as you don't move the
	Repository itself, or alter your $CVSROOT variable, the moved
	directory will continue to be usable.

	CVS remembers where you checked out the directory in the
	"history" file, which can be edited, or even ignored if you
	don't use the "working directory" information displayed by the
	"history" command.


#3C.8	How can I lock files on checkout the way RCS does?

	Think about why you want that ability.  RCS locking is there to
	keep people from breaking individual files.  CVS does the same
	task a different way.  If you are only looking for the consistency
	aspect, then you should just forget about locking.  For normal
	development, there is no need for CVS to lock anything.

	If you want to restrict access to parts of the Repository, see
	the question in Section 4B on "Limiting Access".


+3C.9	What is "checkout -s"?  How is it different from "checkout -c"?

	The '-c' and '-s' options to "checkout" both cause the modules
	file to appear on standard output, but formatted differently.

	"checkout -c" lists the modules file alphabetized by the module
	name.  It also prints all data (including options like '-a' and
	"-o <prog>") specified in the modules file.

	"checkout -s" lists the modules file sorted by "status" field,
	then by module name.  The status field was intended to allow you
	to mark modules with strings of your choice to get a quick sorted
	report based on the data you chose to put in the status fields.  I
	have used it for priority ("Showstopper", etc as tied into a bug
	database), for porting status ("Ported", "Compiled", etc.  when
	porting a large collection of modules), for "assignee" (the person
	responsible for maintenance), and for "test suite" (which
	automatic test procedure to run for a particular module).

	[[CVS 1.3 fails to handle all the flags you can put into the
	modules file.  The '-l' switch in particular causes "checkout -c"
	to dump core on some systems.]]


----------------
-- Section 3D --	"commit", "ci", "com"
----------------

 **** Questions:

 3D.1	What is "commit" for?
=3D.2	If I edit ten files, do I have to type "commit" ten times?
 3D.3	Explain: cvs commit: Up-to-date check failed for `<file>'
 3D.4	What happens if two people try to "commit" conflicting changes?
 3D.5	I committed something and I don't like it.  How do I remove it?
=3D.6	Explain: cvs commit: sticky tag `V3' for file `X' is not a branch
=3D.7	Why does "commit -r <branch_tag>" put new files in the attic?
+3D.8	Why does "commit -r <rev>" ignore <rev> on an added file?


 **** Answers:

 3D.1	What is "commit" for?

	To store new revisions in the Repository, making them visible
	to other users.


=3D.2	If I edit ten files, do I have to type "commit" ten times?

	No.  The "commit" command will take multiple filenames on the
	command line and commit them all with the same log message.
	If the file is unchanged, CVS will skip it.

	Like all CVS commands, "commit" will work on the whole directory
	by default.  Just type "cvs commit" to tell CVS to commit all
	modified files (i.e. the files that "update" would display
	preceded by 'M') in the current directory and in all
	sub-directories.


 3D.3	Explain: cvs commit: Up-to-date check failed for `<file>'

	You may not "commit" a file if your BASE revision (i.e. the
	revision you last checked out, committed or retrieved via
	"update") doesn't match the HEAD revision (i.e the latest revision
	on your branch, usually the Main Branch).

	In other words, someone committed a revision since you last
	executed "checkout", "update" or "commit".  You must now execute
	"update" to merge the other person's changes into your working
	file before "commit" will work.  You are thus protected (somewhat)
	from a common form of race condition in source control systems,
	where a second checkin of minor changes from the same base file
	obliterates the changes made in the first.

	Normally, the "update" command's auto-merge should be followed
	by another round of building and testing before the "commit".


 3D.4	What happens if two people try to "commit" conflicting changes?

	Conflicts can occur only when two developers check out the same
	revision of the same file and make changes.  The first developer
	to commit the file has no chance of seeing the conflict.  Only the
	second developer runs into it, usually when faced with the
	"Up-to-date" error explained in the previous question.

	There are two types of conflicts:

	1. When two developers make changes to the same section of code,
	   the auto-merge caused by "update" will print a 'C' on your
	   terminal and leave "overlap" markers in the file.

	   You are expected to examine and clean them up before committing
	   the file.  (That may be obvious to *some* of you, but . . .)

	2. A more difficult problem arises when two developers change
	   different sections of code, but make calls to, or somehow
	   depend on, the old version of each other's code.

	   The auto-merge does the "right" thing, if you view the file
	   as a series of text lines.  But as a program, the two
	   developers have created a problem for themselves.

	   This is no different from making cross-referential changes in
	   *separate* files.  CVS can't help you.  In a perfect world, you
	   would each refer to the specification and resolve it
	   independently.  In the real world you have to talk/argue, read
	   code, test and debug until the combined changes work again.

	Welcome to simultaneous development.


 3D.5	I committed something and I don't like it.  How do I remove it?

	Though you *can* use the "admin -o" (synonym: "rcs -o") command to
	delete revisions, unless the file you committed is so embarrassing
	that the need to eradicate it overrides the need for being
	careful, you should just grab an old version of the file ("update
	-p -r <previous-rev>" might help here) and commit it on top of the
	offending revision.

	See Section 3B on "admin".


=3D.6	Explain: cvs commit: sticky tag `V3' for file `X' is not a branch

	The message implies two things:

	     1. You created your working directory by using "checkout -r
		V3", or you recently executed "update -r V3".

	     2. The tag named V3 is not a branch tag.


	CVS remembers any "-r <tag/rev>" arguments handed to the
	"checkout" or "update" commands.  This is the "sticky" part.  The
	<tag/rev> is recorded as the CVS working branch, which is the
	branch to which "commit" will add a new revision.

	Branch tags are created when you use the -b switch on the "tag" or
	"rtag" commands.  Branch tags are magic tags that don't create a
	physical branch, but merely mark the revision to branch from when
	the branch is needed.  The first commit to a magic branch creates
	a physical branch in the RCS files.

	You can commit onto the end of the Main Trunk, if you have no
	sticky tag at all, or onto the end of a branch, if you have a
	sticky branch tag.  But you can't commit a file that has a sticky
	tag not pointing to a branch.  CVS assumes a sticky Tag or
	Revision that does not refer to a branch is attached to the middle
	of a series of revisions.  You can't squeeze a new revision
	between two others.  Sticky dates also block commits since they
	never refer to a branch.


	Scenario1:

	    If you don't want a branch and were just looking at an old
	    revision, then you can move back to the Main Branch by typing:

		cvs update -A {optional files, default is whole directory}


	Scenario2:

	    If you really wanted to be on a branch and made an earlier
	    mistake by tagging your branch point with a non-branch tag,
	    you can recover by adding a new branch tag to the old
	    non-branch tag:

		    cvs rtag -b -r <oldtag> <newtag> <module>

	    (It was not a big mistake.  Branch-point tags can be useful.
	     But the <newtag> must have a different name.)

	    If you don't know the <module> name or don't use "modules",
	    you can also use "tag" this way:

		    cvs update -r <oldtag>
		    cvs tag -b <newtag> .

	    Then, to put your working directory onto the branch, you type:

		    cvs update -r <newtag>


	    You can't delete <oldtag> before adding <newtag>, and I would
	    not advise deleting the <oldtag> at all, because it is useful
	    in referring to the branch point.  If you must, you can delete
	    the non-branch tag by:

		    cvs rtag -d <oldtag> <module>
		or
		    cvs tag -d <oldtag> .


	Scenario3:

	    If you made the same mistake as in Scenario2, but really want
	    <oldtag> to be the name of your branch, you can execute a
	    slightly different series of commands to rename it and move
	    your working directory onto the branch:

		    cvs rtag -r <oldtag> <branch_point_tag> <module>
		    cvs rtag -d <oldtag> <module>
		    cvs rtag -b -r <branch_point_tag> <oldtag> <module>

	    Then, if you really must, delete the <branch_point_tag>:

		    cvs rtag -d <branch_point_tag> <module>


	Note:	The unwieldy mixture of "tag" and "rtag" is mostly
		because you can't specify a revision (-r <tag>) to the
		"tag" command.

	See 4C.3 for more details.


=3D.7	Why does "commit -r <branch_tag>" put new files in the attic?

	This was a design choice.  The Attic is a way to keep track of
	files that are no longer on the Main Branch, or ones that were
	*never* on the Main Branch.

	If the file doesn't already exist on the Main branch, committing
	it directly to the BRANCH will stuff it into the Attic.  Such
	files are skipped over when checking out the Main Branch because
	the file isn't on that branch.

	If it didn't go into the Attic, you would be committing the new
	file to the Main branch in addition to the Branch you are working
	on.  This is an undesirable side-effect.

	The file can be retrieved by using the "-r <branch_tag>" option on
	a "checkout" or "update" command.

	See Section 4C, on Branching, for many more details.


+3D.8	Why does "commit -r <rev>" ignore <rev> on an added file?

	The sequence 

		cvs add <file>
		cvs commit -r <rev> <file>

	does not commit the new file <file> with revision <rev> as you
	might expect.  For newly added files (for which "update" would
	display an 'A') the '-r' option is assumed to be a branch tag.  If
	<rev> is numeric, it is ignored.  This might or might not be
	changed in future revisions of CVS, but for now, the following
	commands will allow you to set the revision of the file: (with
	some restrictions)

		cvs add <file>
		cvs commit <file>
		cvs commit -r <rev> <file>

	The first commit causes CVS to look for the highest main branch
	major number in all files in the directory.  Normally it is '1',
	but if you have a file of revision 3.27 in your directory, CVS
	will find the '3' and create revision 3.1 for the first rev of
	<file>.  Normally, the first revision is 1.1.

	As long as <rev> is higher than the initial (calculated as in the
	above) revision, the second commit will work as expected and force
	a second commit even if the file hasn't changed, setting the file
	revision to <rev>.


----------------
-- Section 3E --	"diff", "di", "dif"
----------------

 **** Questions:

 3E.1	What is "diff" for?
=3E.2	Why did "diff" display nothing when I know there are later
	committed revisions in the Repository?
#3E.3	How do I display what changed in the Repository since I last
	executed "checkout", "update" or "commit"?
=3E.4	How do I display the difference between my working file and what
	I checked in last Thursday?
=3E.5	Why can't I pass the --unified option to "diff"?


 **** Answers:

 3E.1	What is "diff" for?

	To display the difference between your working file and a
	committed revision:

		cvs diff -r <tag/rev> <file>

	or between two committed revisions:

		cvs diff -r <tag1/rev1> -r <tag2/rev2> <file>

	Without explicit file names, it "diffs" the whole directory.

	Without explicit revision numbers, it "diffs" your working file
	against the BASE revision, which is the one last checked out,
	updated or committed.

	In the examples above, "-D <date>" may be substituted wherever
	"-r <tag/rev>" appears.  The revision a <date> refers to is the
	revision that existed on that date.


=3E.2	Why did "diff" display nothing when I know there are later
	committed revisions in the Repository?

	By default, "diff" displays the difference between your working
	file and the BASE revision.  If you haven't made any changes to
	the file since your last "checkout", "update" or "commit" there is
	no difference to display.

	To display the difference between your working file and the latest
	revision committed to your current branch, type:

		cvs diff -r HEAD <file>


#3E.3	How do I display what changed in the Repository since I last
	executed "checkout", "update" or "commit"?

	A special tag (interpreted by CVS -- it does not appear in the Tag
	list) named "BASE" always refers to the revision you last checked
	out, updated or committed.  Another special tag named "HEAD"
	always refers to the latest revision on your working branch.

	To compare BASE and HEAD, you type:

		cvs diff -r BASE -r HEAD <file>


=3E.4	How do I display the difference between my working file and what
	I checked in last Thursday?

		cvs diff -D "last Thursday" <file>

	where "last Thursday" is a date string.  To be more precise, the
	argument to the '-D' option is a timestamp.  Many formats are
	accepted.  See the man page under "-D date_spec" for details.


=3E.5	Why can't I pass the --unified option to "diff"?

	There are a few reasons:

	1. CVS passes through only arguments it knows about, because a few
	   arguments are captured and interpreted.

	2. CVS only parses single character '-X' arguments, not the FSF
	   long options.

	3. If you didn't configure RCS and CVS to use the GNU version of
	   diff, long options wouldn't work even if future versions of CVS
	   acquire the ability to pass them through.


	Most of the long options have equivalent single-character options,
	which do work.  The "--unified" option is equivalent to '-u' in
	revisions of GNU diff since 1.15.



----------------
-- Section 3F --	"export", "exp", "ex"
----------------

 **** Questions:

 3F.1	What is "export" for?
=3F.2	Why does it remove the RCS keywords so I can't use the "ident"
	command on the source files?
=3F.3	Can I override the '-kv' flag CVS passes to RCS?
=3F.4	Why the hell not?
 3F.5	Why does "export -D" check out every file in the Attic?


 **** Answers:

 3F.1	What is "export" for?

	"export" checks out a copy of a module in a form intended for
	export outside the CVS environment.  The "export" command produces
	the same directory and file structure as the "checkout" command,
	but it doesn't create "CVS" sub-directories and it removes all the
	RCS keywords from the files.


=3F.2	Why does it remove the RCS keywords so I can't use the "ident"
	command on the source files?

	It removes the RCS keywords, so that if the recipient of the
	exported sources checks them into another set of RCS files (with
	or without CVS), and then makes modifications through RCS or CVS
	commands, the revision numbers that they had when you exported
	them will be preserved.  (That ident no longer works is just an
	unfortunate side effect.)
    
	The theory is that you are exporting the sources to someone else
	who will make independent changes, and at some point you or they
	will want to know what revisions from your Repository they started
	with (probably to merge changes, or to try to decide whether to
	merge changes).

	A better way to handle this situation would be to give them their
	own branch of your Repository.  They would need to remember to
	checkin the exported sources with RCS IDs intact (ci -k) so that
	their changes would get revision numbers from the branch, rather
	than starting at 1.1 again.  Perhaps a future version of CVS will
	provide a way to export sources this way.

				Contributed by Dan Franklin


=3F.3	Can I override the '-kv' flag CVS passes to RCS?

	Not in CVS 1.3.  Maybe later.


=3F.4	Why the hell not?

	Export is intended for a specific purpose -- to remove all trace
	of revision control on the way *out* of CVS.  Maybe in the future
	CVS will allow the -kv default to be overridden.


 3F.5	Why does "export -D" check out every file in the Attic?

	See the explanation of the same problem with "update -D"
	contained in section 5B.



----------------
-- Section 3G --	"history", "hi", "his"
----------------

 **** Questions:

 3G.1	What is "history" for?
 3G.2	Of what use is it?
 3G.3	What is this, Big Brother?
 3G.4	I deleted my working directory and "history" still says I have
	it checked out.  How do I fix it?
 3G.5	So I *can* edit the History file?
 3G.6	Why does the history file grow so quickly?
 3G.7	What is the difference between "cvs history -r <tag/rev>" and
	"cvs history -t <tag>"?
 3G.8	Why does "cvs history -c -t <tag>" fail to print anything?
 3G.9	"cvs history -a -o" only printed one line for each checked-out
	module.  Shouldn't it print all the directories where the
	modules are checked out?
=3G.10	I can't figure out "history", can you give me concrete examples?


 **** Answers:

 3G.1	What is "history" for?

	To provide information difficult or impossible to extract out of
	the RCS files, such as a "tag" history or a summary of module
	activities.


 3G.2	Of what use is it?

	I have found it useful in a number of ways, including:

	1. Providing a list of files changed since

	   - A tagged release.
	   - Yesterday, last Thursday, or a specific date.
	   - Someone changed a specific file.

	2. Providing a list of special events:

	   - Files added or removed since one of the above events.
	   - Merge failures since one of the above events.  (Where did the
	     conflicts occur?)
	   - Has anyone (and who) grabbed the revision of this file I
	     committed last week, or are they still working blind?

	3. Telling me how often a file/directory/module has been changed.

	4. Dumping a summary of work done on a particular module,
	   including who last worked on it and what changed.

	5. Displaying the checked-out modules and where they are being
	   worked on.

	6. To tell me what users "joe" and "malcolm" have done this week.


 3G.3	What is this, Big Brother?

		War is Peace.
		Freedom is Slavery.
		Ignorance is Strength.

	Normally manager types and those with the power to play Big
	Brother don't care about this information.  The Software Engineer
	responsible for integration usually wants to know who is working
	on what and what changed.  Use your imagination.


 3G.4	I deleted my working directory and "history" still says I have
	it checked out.  How do I fix it?

	In later versions of CVS, you can use the '-f' option which
	forcibly adds a "release" record to the history file.  If your
	version of "release" doesn't have the '-f' option, you have
	to edit the $CVSROOT/CVSROOT/history file.

	You can remove the last 'O' line in the history file referring
	to the module in question or add an 'F' record.


 3G.5	So I *can* edit the History file?

	Yes, but if you are using history at all, you should take a little
	care not to lose information.  I normally use Emacs on the file,
	since it can detect that a file has changed out from under it.
	You could also copy and zero out the history file, edit the copy
	and append any new records to the edited copy before replacing it.


 3G.6	Why does the history file grow so quickly?

	It stores 'U' records, which come in handy sometimes when you
	are tracking whether people have updated each other's code
	before testing.  There should (and probably will sometime) be a
	way to choose what kinds of events go into the history file.

	The contributed "cln_hist.pl" script will remove all the 'U'
	records, plus matching pairs of 'O' and 'F' records during
	your normal clean up of the history file.


 3G.7	What is the difference between "cvs history -r <tag/rev>" and
	"cvs history -t <tag>"?

	The '-t' option looks for a Tag record stored by "rtag" in the
	history file and limits the search to dates after the last <tag>
	of the given name was added.

	The '-r' option was intended to search all files looking for the
	<tag> in the RCS files.  It takes forever and needs to be
	rewritten.


 3G.8	Why does "cvs history -c -t <tag>" fail to print anything?

	You have been using "tag" instead of "rtag".  The "tag" command
	currently doesn't store a history record.  This is another remnant
	of CVS's earlier firm belief in "modules".


 3G.9	"cvs history -a -o" only printed one line for each checked-out
	module.  Shouldn't it print all the directories where the
	modules are checked out?

	Not as designed.

	Command			Question it is supposed to answer.
	----------------	------------------------------------------
	cvs history -o		What modules do I have checked out?
	cvs history -a -o	<same for all users>

	cvs history -o -w	What working directories have I created
				and what modules are in them?
	cvs history -a -o -w	<same for every user>

	The -o option chooses the "checked out modules" report, which is
	the default history report.


=3G.10	I can't figure out "history", can you give me concrete examples?

	Default output selects records only for the user who executes the
	"history" command.  To see records for other users, add one or
	more "-u user" options or the '-a' option to select *all* users.

	To list (for the selected users):	Type "cvs history" and:

	* Checked out modules:			-o    (the default)
	* Files added since creation:		-x A
	* Modified files since creation:	-c
	* Modified files since last Friday:	-c -D 'last Friday'
	* Modified files since TAG was added:	-c -t <tag>
	* Modified files since TAG on files:	-c -r <tag>
	* Last modifier of file/Repository X?	-c -l -[fp] X
	* Modified files since string "str":	-c -b str
	* Tag history:	(Actually "rtag".)	-T
	* History of file/Repository/module X:	-[fpn] X
	* Module report on "module":		-m module


----------------
-- Section 3H --	"import", "im", "imp"
----------------

 **** Questions:

=3H.1	What is "import" for?
=3H.2	How am I supposed to use "import"?
=3H.3	Why does import put files on a branch?  Why can't you put it on
	the Main Trunk and let me work on a branch?
 3H.4	Is there any way to import binary files?
=3H.5	Why does "import" corrupt some binary files?
 3H.6	How do I keep "import" from expanding all the $\Revision$ strings
	to be 1.1.1.1?
#3H.7	I imported some files for the Yarg compiler that compiles files
	with a suffix of ".yarg" and whose comment prefix is "YARG> ".
	When I check them out, they will no longer compile because they
	have this junk in them.  Why?
 3H.8	How do I make "import" save the timestamps on the original files?
 3H.9	Why didn't "import" ignore the directories I told it to?
 3H.10	Why can't I "import" 3 releases on different branches?
 3H.11	What do I do if the Vendor adds or deletes files between releases?
 3H.12	What about if the Vendor changes the names of files or
	directories, or rearranges the whole structure between releases?
 3H.13	I thought "import" was for Vendor releases, why would I use it
	for code of my own?  Do I have to use import?
=3H.14	How do I import a large Vendor release?
+3H.15	Explain: ERROR: cannot create link to <file>: Permission denied


 **** Answers:

=3H.1	What is "import" for?

	The "import" command is a fast way to insert a whole tree of files
	into CVS.

	The first "import" to a particular file within the Repository
	creates an RCS file with a single revision on the "Vendor branch."
	Subsequent "import"s of the same file within the Repository append
	a new revision onto the Vendor branch.  It does not, as some seem
	to believe, create a new branch for each "import".  All "imports"
	are appended to the single Vendor branch.

	If the file hasn't changed, no new revision is created -- the new
	"Release-Tag" is added to the previous revision.

	After the import is finished, files you have not changed locally
	are considered to have changed in the "Main line of development".
	Files you *have* changed locally must have the new Vendor code
	merged into them before they are visible on the "Main line".

		See 4C.6 and 4C.15


=3H.2	How am I supposed to use "import"?

	Create a source directory containing only the files you want to
	import.  Make sure you clean up any cruft left over from previous
	builds or editing.  You want to make sure that the directory
	contains only what you want to call "source" from which everything
	else is built.

	"cd" into your source directory and type:

	    cvs import -m "Message" <repos> <Vendor-Tag> <Release-Tag>


	where <repos> is a relative directory pathname within the
	Repository.

	For example, if the FSF, CVS, Make and I are still active in the
	year 2015, I'll import version 89.53 of GNU make this way:

	    cvs import -m "GNUmake V89.53" gnu/make GNU GNUMAKE_89_53

	See 3H.14 for more details.


=3H.3	Why does import put files on a branch?  Why can't you put it on
	the Main Trunk and let me work on a branch?

	Design choice.  If you don't like the Vendor branch, you can use
	the RCS "ci" command to generate all the RCS (",v") files and move
	them into the Repository directly.

	Note that the CVS "Main Branch" and the RCS Main Trunk are not the
	same.  Placing files on the Vendor Branch doesn't keep you from
	creating a development branch to work on.

	See Section 4C, on Branching.


 3H.4	Is there any way to import binary files?

	See 4D.1 on Binary files.


=3H.5	Why does "import" corrupt some binary files?

	The RCS "co" command, when it is invoked by a CVS "checkout" or
	"update" (or after a "commit") command, searches for and expands a
	list of keywords within the file.  They are documented in the RCS
	"co" man page.  Strings such as "$\Id$" (or "$\Id:"), or
	"$\Revision$" (or "$\Revision:") are altered to the include the
	indicated information.

	[[Note: The keywords should appear in the text without the '\'
	  character I have inserted to *avoid* expansion here.  The only
	  real RCS keywords in this document are at the top of the file,
	  where I store the Revision and Date.]]

	If RCS keyword strings show up in a binary file, they will be
	altered unless you set the '-ko' option on the RCS files to tell
	RCS to keep the original keyword values and not to expand new
	ones.  After "import", you can set the '-ko' option this way:

		cvs admin -ko <file>
		rm <file>
		cvs update <file>

	See 4D.1 on Binary files.


 3H.6	How do I keep "import" from expanding all the $\Revision$ strings
	to be 1.1.1.1?

	If you want to leave old RCS keywords as they are, you can use the
	'-ko' trick described above.  In the future, "import" might
	sprout a '-ko' option of its own, so you don't have to execute two
	commands.


#3H.7	I imported some files for the Yarg compiler that compiles files
	with a suffix of ".yarg" and whose comment prefix is "YARG> ".
	When I check them out, they will no longer compile because they
	have this junk in them.  Why?

	YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>
	YARG> $\Log:
	# Revision 1.3  1998/03/03  00:16:16  bubba
	# What is 2+2 anyway?
	#
	# Revision 1.2  1998/03/03  00:15:15  bubba
	# Added scorekeeping.
	YARG>
	YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>YARG>


	Well bubba, "Yarg" hasn't hit the big time yet.  Neither RCS nor
	CVS know about your suffix or your comment prefix.  So you have
	two choices:

	1. Check out the Yarg-less module, and tell all the files about
	   your comment prefix.  Visit each directory and type:

		cvs admin -c"YARG> " *.yarg

	   If *all* files in the whole directory tree are Yarg files,
	   you can use this instead:

		cvs admin -c"YARG> " .

	   Then save any changes you made, remove all the "*.yarg" files
	   and grab new copies from the Repository:

		rm *.yarg  (or: find . -name '*.yarg' -exec rm {} ';')
		cvs update

	   It might be faster to remove the whole directory and check it
	   out again.
		
	2. Change the import.c file in the CVS sources and add the .yarg
	   suffix, along with the "YARG> " comment prefix to the
	   "comtable" array.

	   If you ever plan to add new files with $\Log in them, you
	   should also go into the RCS sources and make the same change in
	   the table contained in the "rcsfnms.c" file.

	   Then delete the imported files from the Repository and
	   re-"import" the sources. 


 3H.8	How do I make "import" save the timestamps on the original files?

	In the released CVS 1.3, there is no way.  In the coming patch
	release, there will supposedly be a '-d' option to save the dates
	of the files rather than the current date.

	See 4D.8 for more details.


 3H.9	Why didn't "import" ignore the directories I told it to?

	See 2D.11.


 3H.10	Why can't I "import" 3 releases on different branches?

	I'll bet you typed something like this:

		cd /src/blasto.v2
		cvs import -b 1.1.2  VENDOR2 Version2
		cd /src/blasto.v3
		cvs import -b 1.1.3  VENDOR3 Version3
		cd /src/blasto.v4
		cvs import -b 1.1.4  VENDOR4 Version4

	This is wrong, or at least it won't help you much.  You have
	created three separate Vendor branches, which is probably not
	what you wanted.

	Earlier versions of CVS, as described in Brian Berliner's Usenix
	paper, tried to support multiple Vendor branches on the theory
	that you might receive source for the *same* program from multiple
	vendors.  It turns out that this is very rare, whereas the need to
	branch in *your* development, for releases and for project
	branches, is much greater.

	So the model now is to use a single vendor branch to contain a
	series of releases from the same vendor.  Your work moves along
	on the Main Trunk, or on a CVS branch to support a real
	"branch in development".

	To set this up, you should type this instead of the above:

		cd /src/blasto.v2
		cvs import VENDOR Version2
		cd /src/blasto.v3
		cvs import VENDOR Version3
		cd /src/blasto.v4
		cvs import VENDOR Version4


 3H.11	What do I do if the Vendor adds or deletes files between releases?

	Added files show up with no extra effort.  To handle "removed"
	files, you should always compare the tree structure of the new
	release against the one you have in your Repository.  If the
	Vendor has removed files since the previous release, go into a
	working directory containing your current version of the sources
	and "remove" (followed by "commit" to make it really take effect)
	each file that is no longer in the latest release.

	Using this scheme will allow you to "checkout" any version of
	the vendor's code, with the correct revisions and files, by
	using "checkout -r Version[234]".


 3H.12	What about if the Vendor changes the names of files or
	directories, or rearranges the whole structure between releases?

	Currently CVS can't handle this cleanly.  It requires
	"renaming" a bunch of files or directories.

	See 4B.9 on "renaming" for more details.

	What I generally do is to close the Repository for a while and
	make changes in both the Repository and in a copy of the vendor
	release until the structure matches, then execute the import.

	If you ever have to check out and build an old version, you may
	have to use the new, or completely different Makefiles.


 3H.13	I thought "import" was for Vendor releases, why would I use it
	for code of my own?  Do I have to use import?

	For code you produce yourself, "import" is a convenience for
	fast insertion.  It is not necessary.  You can just as easily
	checkin all the files using the RCS "ci" command and move the
	resulting ",v" files into the Repository.

	See Section 4B, on Setting up and Managing the Repository.


=3H.14	How do I import a large Vendor release?

	When the sum of the changes made by the Vendor and the changes
	made by local developers is small, "import" is not a big
	problem.  But when you are managing a large Repository, any care
	taken up front will save you time later.

	First read the following, then, before executing "import", see the
	questions in Section 4C dealing with branch merges and Vendor
	branch merges.


	1. The first step is to make sure the structure of the new files
	   matches the structure of the current Repository.

	   Run "find . -print | sort" on both trees and "diff" the output.

	2. Alter the "source" tree until the "diff" (of the list of
	   filenames, not of the whole trees) shows that the directory
	   structures are equivalent.

	   The "comm" command, if you have it, can help figure out what
	   has been added or deleted between releases.

	3. If they deleted any files, you can handle them cleanly with
	   "cvs remove".  The command "comm -23 files.old files.new" will
	   show you a list of files that need to be removed.

	4. If they renamed any files, see 4B.9 on renaming files.

	5. When you have dealt with removed and renamed files, then you
	   can execute the import:

	   cd <new source>
	   cvs import -m "Message" <repos> <VendorTag> <ReleaseTag>

	   Where

	   Message	is the log message to be stored in the RCS files.

	   <repos>	is a relative path to a directory within the
			Repository.  The directory <new source> must be at
			the same relative level within the new sources as
			the <repos> you give is within the Repository.  (I
			realize this is not obvious.  Experiment first.)

	   <VendorTag>	is a Tag used to identify the Vendor who sent you
			the files you are importing.  All "imports" into
			the same <repos> *must* use the same VendorTag.
			You can find it later by using the "log" command.

	   <ReleaseTag>	is a Tag used to identify the particular release
			of the software you are importing.  It must be
			unique and should be mnemonic -- at least include
			the revision number in it.  (Note: you can't use
			'.' characters in a Tag.  Substitute '_' or '-'.)

	6. *SAVE* the output from the import command.

	7. There will be six categories of files to deal with.
	   (Actually there are eight, but you have already dealt with
	   "removed" and "renamed" files.)

	   If this is the first "import" into a given <repos> directory,
	   only the first three of these ('I', 'L' and 'N') can occur.


	   a. Ignored file.

		CVS prints:	I filename

		You'll need to examine it to see if it *should* have been
		ignored.  Alternatively, you can examine every file in the
		"find" at the beginning and use the "import -I !"
		option to avoid ignoring anything.


	   b. Symbolic link.

		CVS prints:	L linkname

		Links are "ignored", but you'll probably want to create
		a "checkout helper" function to regenerate them.


	   c. New file.

		CVS prints:	N filename

		CVS creates a new file in the Repository.  You don't
		have to do anything to the file, but you might have to
		change Makefiles to refer to it.


	   d. A file unchanged by the Vendor since its last release.

		CVS prints:	U filename

		CVS will notice this and simply add the new ReleaseTag
		to the latest rev on the Vendor branch.

		No work will be needed by you, whether you have changed
		the file or not.  No one will notice anything.

	   e. A file changed by the Vendor, but not by you.

		CVS prints:	U filename

		CVS should add the file onto the vendor branch and
		attach the Release Tag to it.

		When you next execute "update" in any working directory
		you'll get the new revision.


	   f. A file changed by both the Vendor and by you.

		CVS prints:	C filename

		These are the trouble files.  For each of these files
		(or in groups -- I usually do one directory at a
		time), you must execute:

		    cvs update -j <PreviousReleaseTag> -j <ReleaseTag>

		It will print either 'M' (if no overlaps) or 'C', if
		overlaps.  If a 'C' shows up, you'll need to edit the
		file by hand.

		Then, for every file, you'll need to execute"cvs commit".

		See the part of Section 4C dealing with branch merges.


+3H.15	Explain: ERROR: cannot create link to <file>: Permission denied

	This error appears when you try to execute a second (or later)
	"import" into the same module from a directory to which you don't
	have write access.

	The "link error" is caused by a feature purposely added to
	speed up the import.

	Though the error message is somewhat strange, it indicates that
	"import" is supposed to be executed only in writable directories.


----------------
-- Section 3I --	"log", "lo", "rlog"
----------------

 **** Questions:

=3I.1	What is "log" for?
 3I.2	How do I extract the log entries between two revisions?
=3I.3	How do I extract the log entries on a whole branch?
=3I.4	How do I generate ChangeLogs from RCS logs?
=3I.5	Why does "log" tell me a file was committed exactly 5 hours later
	than I know it was?


 **** Answers:

=3I.1	What is "log" for?

	To provide an interface to the RCS "rlog" command, which displays
	information about the underlying RCS files, including the revision
	history and Tag (what RCS calls "symbol") list.


 3I.2	How do I extract the log entries between two revisions?

	If both <rev1> and <rev2> are on the same branch, you can get
	what you are looking for with:

		cvs log -r<rev1>:<rev2> <file>

	If either <rev1> or <rev2> contain '-' characters, it will
	complain and fail due to RCS's continued support of '-' as an
	alternate range character.

	<rev1> and <rev2> can be tag/symbol names, but they have to be
	on the same branch, whether they are numeric or symbolic.


=3I.3	How do I extract the log entries on a whole branch?

		cvs log -r<rev> <file>

	where <rev> must be a branch revision (one with an even number
	of dots) or a *non-branch* tag on a branch revision.  Non-branch
	tags on a branch revision are not normally attached by CVS, to add
	one you will have to explicitly tag a physical branch number
	within each file.  Since these branch numbers are almost never the
	same in different files, this command is not all that useful.


 3I.4	How do I generate ChangeLogs from RCS logs?

	A program called rcs2log is distributed as part of GNU Emacs 19.
	This program should also appear in the CVS FTP archive.


=3I.5	Why does "log" tell me a file was committed exactly 5 hours later
	than I know it was?

	I can tell by this question that you were working in a time zone
	that is 5 hours behind GMT (e.g. the U.S. East Coast in winter).

	RCS file dates are stored in GMT to allow users in different time
	zones to agree on the meaning of a timestamp.  At first glance
	this doesn't seem necessary, but many companies use distributed
	file systems, such as NFS or AFS, across multiple timezones.

	Some standard form must be used.  GMT, as the "grid origin", is an
	obvious candidate.  The only other reasonable choice is to put the
	timezone information in all the time stamps, but that changes the
	RCS file format incompatibly, a step which has been avoided in the
	last few RCS releases.


----------------
-- Section 3J --	"patch", "pa", "rdiff"
----------------

 **** Questions:

 3J.1	What is "patch" for?
 3J.2	Why does "patch" include files from the Attic when I use '-D'?
 3J.3	How do I make "patch" produce a patch for one or two files?
	It seems to work only with modules.


 **** Answers:

 3J.1	What is "patch" for?

	To produce a "diff" between tagged releases to be handed to the
	"patch" command at other sites.  This is the standard way that
	source patches are distributed on the network.


 3J.2	Why does "patch" include files from the Attic when I use '-D'?

	See the explanation of the same problem with "update -D"
	contained in section 5B.


 3J.3	How do I make "patch" produce a patch for one or two files?
	It seems to work only with modules.

	Patch is intended for producing patches of whole modules between
	releases to be distributed to remote sites.  Instead of "patch",
	you can use the "diff" command with the '-c' context option:

	     cvs diff -c -r <rev/tag> -r <rev/tag> <file1> . . .

	The patch command will be able to merge such a "diff" into the
	remote source files.

	If the version of "diff" you are using supports the '-u' option,
	to produce the more compact "Unidiff" format, the latest
	revisions of the patch command understand that too.



----------------
-- Section 3K --	"release", "re", "rel"
----------------


 **** Questions:

 3K.1	What is "release" for?
 3K.2	Why does release -d delete directories within my directory that
	weren't ever in the CVS Repository?
 3K.3	Why can't I reverse a "cvs checkout path/name/subdir" with a
	"cvs release path/name/subdir" without an "unknown module name"?
 3K.4	Why can't I "release" portions of a checked out directory?  I
	should be able to "release" any file or sub-directory within
	my working directory.
 3K.5	I removed the tree that I was about to start working on.  How do I
	tell cvs that I want to release it if I don't have it anymore?
 3K.6	Why doesn't "release -d module" reverse a "checkout module"?
 3K.7	Why can't I release a module renamed with "cvs checkout -d"?


 **** Answers:

 3K.1	What is "release" for?

	To register that a module is no longer in use.  It is intended
	to reverse the effects of a "checkout" by adding a record to
	the history file to balance the checkout record and by
	optionally allowing you to delete the checked-out directory
	associated with the module name.


 3K.2	Why does release -d delete directories within my directory that
	weren't ever in the CVS Repository?

	A simplistic implementation.  (I can say this -- I wrote it.)

	The "release" function was written under the assumptions that the
	"module name" is a first class, unavoidable interface to the
	Repository, allowing no way to retrieve anything other than by
	module name and a module is a self-contained entity with no
	foreign directories allowed.  Though it is easier to program that
	way, many users of CVS believe the modules support to be too
	primitive to allow such a limitation.

	Since "release" was written, other parts of CVS broke those
	assumptions.  It will be upgraded slightly in the next release and
	rewritten in the future.


 3K.3	Why can't I reverse a "cvs checkout path/name/subdir" with a
	"cvs release path/name/subdir" without an "unknown module name"?

	Again, "release" is too primitive.  It believes, truly
	*believes* in modules, not relative paths.  I can't *believe*
	how many times I've been asked this.  It was a hack of the
	moment with a particular use in mind.  I had no idea it was
	going to cause so much trouble.  I'll *fix* it already!  :-)


 3K.4	Why can't I "release" portions of a checked out directory?  I
	should be able to "release" any file or sub-directory within
	my working directory.

	Again, "release" believes in modules.  Breaking it into bits
	wasn't part of the plan.  In the future, "release" might become
	sophisticated enough to handle both the reversal of a "checkout"
	and the deletion of random portions of the working directory, but
	it isn't that way now.


 3K.5	I removed the tree that I was about to start working on.  How do I
	tell cvs that I want to release it if I don't have it anymore?

	See 3G.4.


 3K.6	Why doesn't "release -d module" reverse a "checkout module"?

	It does, if you are using "module" in a way that "release"
	expects: a non-alias string in the left column of the "modules"
	database.

	If "module" is really an alias, or if you are using a relative
	path in the place of "module", or if you renamed the directory
	with the -d option in the modules file or on the "checkout"
	command line, then the current version of "release" won't work.

	Future versions of "release" will probably fix most of these.


 3K.7	Why can't I release a module renamed with "cvs checkout -d"?

	The current version of "release" doesn't know how to track the
	renaming option ('-d') of the "checkout" command.  It will
	probably be fixed in the future.



----------------
-- Section 3L --	"remove", "rm", "delete"
----------------

 **** Questions:

 3L.1	What is "remove" for?
 3L.2	Why doesn't "remove" work on directories when it appears to try?
 3L.3	I don't like removing files.  Is there another way to ignore them?
 3L.4	I just removed a file.  How do I resurrect it?
 3L.5	Why doesn't "remove" delete the file?  Instead, it prints:
	cvs remove: no files removed; use `rm' to remove the file first


 **** Answers:

 3L.1	What is "remove" for?

	To remove a file from the working branch.  It removes a file from
	the main branch by placing it in an "Attic" directory.


 3L.2	Why doesn't "remove" work on directories when it appears to try?

	Oversight.  It should be able to delete an empty directory, but
	you still don't have a way to remember when it was there and when
	it disappeared to allow the "-D <date>" option to work.

	You'll have to remove the working directory and the matching
	directory in the Repository.


 3L.3	I don't like removing files.  Is there another way to ignore them?

	There's no reason to be hasty in using the "remove" command.

	If there is a way to ignore files in your build procedures, I'd
	just do that.  Later, when you decide that the files are really
	ancient, you can execute a "remove" command to clean up.

	The CVS "ignore" concept can't ignore files already in CVS.


 3L.4	I just removed a file.  How do I resurrect it?

	If you executed  "remove", but haven't typed "commit" (you can
	tell this by the 'R' notation that "update" prints next to the
	file), you can execute "add" to reverse the "remove".

	If you followed the "remove" with a "commit", you'll have
	to move it back out of the Attic by hand:

	I use something like this: (csh-like syntax)

		set repos = `cat CVS/Repository`
		mv $repos/Attic/filename,v $repos/filename,v

	(If you use relative paths in your Repository files, that first
	line becomes: set repos = $CVSROOT/`cat CVS/Repository`)

	While a file is in the Attic, you can't "add" another file by
	the same name.	To add such a file you either have to move it by
	hand as in the above, or delete it from the Attic.

	The main reason for the Attic is to retain files with tags in
	them.  If you execute: "update -r <oldtag>", files with <oldtag>
	attached to some revision will be taken from the normal Repository
	area and from the Attic.  That's why you can't "add" a file with
	the same name.  "remove" only moves a file off the main branch, it
	doesn't obliterate it.


 3L.5	Why doesn't "remove" delete the file?  Instead, it prints:
	cvs remove: no files removed; use `rm' to remove the file first

	Design choice.  Unix software written within last decade, usually
	requires an extra verification step, such as answering a question
	or adding a flag on the command line.  CVS currently requires that
	you delete the file first.

	Future versions of CVS might contain a '-f' switch that deletes
	the existing file without complaining.


----------------
-- Section 3M --	"rtag", "rt", "rfreeze"
----------------

(See the "tag" section below for questions in common with "rtag".)


 **** Questions:

 3M.1	What is "rtag" for?
 3M.2	Why would you use "rtag"?  It assumes a static Repository.


 **** Answers:

 3M.1	What is "rtag" for?

	To add a symbolic label (a "tag") to the last committed revisions
	of a module directly in the Repository.


 3M.2	Why would you use "rtag"?  It assumes a static Repository.

	Though the "tag" command is more useful in marking the
	revisions you have in a particular working directory, "rtag" is
	much handier for whole-Repository actions, which occur at major
	release boundaries.



----------------
-- Section 3N --	"status", "st", "stat"
----------------

 **** Questions:

=3N.1	What is "status" for?
 3N.2	Why does "status" limit the File: at the top to 17 characters?
+3N.3	Shouldn't the status "Needs Checkout" be "Needs Update"?


 **** Answers:

=3N.1	What is "status" for?

	To display the status of files, including the revision and branch
	you are working on and the existence of "sticky" information.


 3N.2	Why does "status" limit the File: at the top to 17 characters?

	Designed that way to line up with other data.  You can find the
	whole filename in the line beginning with "RCS version:", which is
	not limited in length.


+3N.3	Shouldn't the status "Needs Checkout" be "Needs Update"?

	Probably.  Maybe in future revisions.



----------------
-- Section 3O --	"tag", "ta", "freeze"
----------------

 **** Questions:

 3O.1	What is "tag" for?
=3O.2	What is the difference between "tag" and "rtag"?
=3O.3	Why does "tag -b" not put a tag on the Branch Point revision?
	How do I refer to the Branch Point?
-3O.4	So "tag" labels a bunch of files.  What do you use a Tag for?
 3O.5	How do I get "tag" and "rtag" to send mail the way "commit" does?
 3O.6	Why can't "tag" handle the '-r' option that "rtag" takes?
-3O.7	After a "tag <tag>" in my working directory, why doesn't "checkout
	-r <tag>" somewhere else produce copy of my current files?
#3O.8	Why doesn't "tag" write a history record the way "rtag" does?


 **** Answers:

 3O.1	What is "tag" for?

	To add a symbolic label (a "tag") to the RCS files last checked
	out, updated or committed in a working directory.


=3O.2	What is the difference between "tag" and "rtag"?

	The end result of both commands is that a <tag>, or symbolic name,
	is attached to a particular revision of a collection of files.

	The differences lie in:

	1. The collection of files they work on.

	    "rtag" works on the collection of files referred to by a
	    "module" name, as defined in the "modules" file.

	    "tag" works on files and directories in the current working
	    directory.

	    Both commands recursively follow directory hierarchies within
	    the named files and directories.

	2. The revisions they choose to tag.

	    "rtag" places a tag on the latest committed revision of
	    each file on the branch specified by the '-r' option.  By
	    default it tags the Main Branch.

	    "tag" places a tag on the BASE (i.e. last checked out, updated
	    or committed) revision of each file found in the working
	    directory.

	3. A different set of command line options.

	   For example, "rtag" takes a "-r <oldtag>" option to retag an
	   existing tag.  The "tag" command does not.

	4. How it is logged.

	   Currently "rtag" records the <tag> and the module in the
	   "history" file, while "tag" does not.


=3O.3	Why does "tag -b" not put a tag on the Branch Point revision?
	How do I refer to the Branch Point?

	Design decision.  If everything works perfectly, the "update -j"
	command will do the merge you need and you don't need to check up
	on it by playing with the branch point revision.

	The '-b' option attaches a magic branch tag to allow CVS later to
	figure out the branch point.  The actual revision that <tag> is
	attached to does not exist.  References to the branch tag are
	equivalent to references to the latest revision on the branch.

	There is no way to refer to the branch point without adding a
	non-branch tag.  See 4C.3 on Creating a Branch.


-3O.4	So "tag" labels a bunch of files.  What do you use a Tag for?

	You use it to "checkout" the labeled collection of files as a
	single object, referring to it by name.

	Anywhere a revision number can be used a Tag can be used.  In fact
	tags are more useful because they draw a line through a collection
	of files, marking a development milestone.

	The way to think about a Tag is as a curve drawn through a matrix
	of filename vs. revision number.  Consider this:

	Say we have 5 files (in some arbitrary modules, some may be in 2
	or more modules by name, some may be in 2 or more modules because
	of the Repository tree structure) with the following revisions:

		file1	file2	file3	file4	file5

		1.1	1.1	1.1	1.1  /--1.1*	  <-*-	<tag>
		1.2*-	1.2	1.2    -1.2*-
		1.3  \-	1.3*-	1.3   /	1.3
		1.4	     \	1.4  /	1.4
			      \-1.5*-	1.5
				1.6

	At some time in the past, the '*' versions were tagged.  Think
	of the <tag> as a handle attached to the curve drawn through the
	tagged revisions.  When you pull on the handle, you get all the
	tagged revisions.  Another way to look at it is that you draw a
	straight line through the set of revisions you care about and
	shuffle the other revisions accordingly.  Like this:

		file1	file2	file3	file4	file5

				1.1
				1.2
			1.1	1.3			  _
		1.1	1.2	1.4	1.1		 /
		1.2*----1.3*----1.5*----1.2*----1.1	(--- <-- Look here
		1.3		1.6	1.3		 \_
		1.4			1.4
					1.5

	I find that using these visual aids, it is much easier to
	understand what a <tag> is and what it is useful for.


 3O.5	How do I get "tag" and "rtag" to send mail the way "commit" does?

	The "commit" command is supported by two files ("commitinfo"
	and "loginfo") not used by other commands.  To do logging the
	same way for "tag" and "rtag" would require another file like
	loginfo, which currently doesn't exist.

	The "rtag" command requires a "module" entry, which can specify a
	"tag" program using the "-t programname" option on the module
	line.

	There is no equivalent support for "tag".


 3O.6	Why can't "tag" handle the '-r' option that "rtag" takes?

	Oversight.  The answer is probably "Fixed in a Future Release."


-3O.7	After a "tag <tag>" in my working directory, why doesn't "checkout
	-r <tag>" somewhere else produce copy of my current files?

	The only reason this would fail, other than misspelling the <tag>
	string, is that you didn't "commit" your work before "tagging" it.
	Only committed revisions may be tagged.  Modified files are not
	marked for later tagging.


#3O.8	Why doesn't "tag" write a history record the way "rtag" does?

	The "rtag" command was originally intended to place major
	"release" tags onto modules.  The "tag" functionality was
	developed to *move* the more significant tag when slight changes
	to individual files sneaked in after the release tag was stamped
	onto the Repository.

	The significant event was the "rtag", which was recorded in the
	"history" file for the "history -T" option to work.

	It turns out that "tag" is more useful than "rtag", so the model
	has changed.  Future revisions of CVS will probably store both
	kinds of tags in the history file.



----------------
-- Section 3P --	"update", "up", "upd"
----------------

 **** Questions:

 3P.1	What is "update" for?
=3P.2	What do 'U', 'M' and 'C' mean when I type "update"?  Are they
	different for "cvs -n update"?
 3P.3	What's the difference between "update" and "checkout"?
=3P.4	Why don't I get new files when I execute "update"?
#3P.5	Why does "update" say 'M' both for plain modified files and for
	successful (i.e. conflict-free) merges?  Aren't they different?
=3P.6	After a merge ("update" or "update -j"), why doesn't CVS remember
	the conflict and not allow you to commit the result until the
	conflict is resolved?
 3P.7	Is there a feature to tell me what I have changed, added and
	removed without changing anything?
=3P.8	Why does "cvs update" not flag directories that are not in the
	Repository as it does with new files?
 3P.9	Why are all my files deleted when I execute "update"?


 **** Answers:

 3P.1	What is "update" for?

	The "update" command is by far the most important command and is
	probably also the most used command.

	It has five purposes:  (And many options.)

	1. To display the status of your working files.

	   Though a plain "update" also displays the status, it does so
	   after possibly altering your working directory.  To see the
	   status of your working files without changing anything, type:

		cvs -n update {optional list of files}


	2. To merge changes made to the branch you are working on into
	   your working files.

	   Each working directory is attached to a branch, usually the
	   Main branch.  To merge changes made on your working branch by
	   other people into your working files, type:

		cvs update {optional list of files}


	3. To merge changes made to another branch into the branch you are
	   working on (your "working branch").

	   If you want to grab a whole branch, from the branch point,
	   which is assumed to be on the Main Branch, to the end of the
	   branch, you type:

		cvs update -j <branch_tag> {optional files}

	   If you want to grab the changes made between two tags or
	   revisions, you type:

		cvs update -j <tag1/rev1> -j <tag2/rev2> {optional files}

	   (If you are working with a single file, the Tags could also be
	    revisions numbers.  Unless you take really unusual care to
	    match revision numbers across different files (a waste of time
	    given the way Tags work), using revision numbers in places of
	    the Tags for multiple files would be meaningless.)


	4. To move your working directory to another branch.

	   A working directory is presumed to be attached to (or working
	   on) a particular branch, usually the Main branch.  To alter
	   what CVS believes to be your working branch, you "move" to that
	   branch.

	   To move to a tagged branch, type:

		cvs update -r <branch_tag> {optional files}

	   To move to the Main Branch, type:

		cvs update -A {optional files}


	5. To retrieve old revisions of files.

	   This option is similar to 4 above but you are not restricted to
	   using a <branch_tag>.  You may specify any revision or Tag with
	   '-r' and get the specified revision or the tagged revision:

		cvs update -r <tag/rev> {optional files}

	   Or you may specify any date with '-D':

		cvs update -D <date> {optional files}

	   The '-p' option sends the revisions to standard output
	   (normally your terminal) rather than setting the "sticky" tag
	   and changing the files.


=3P.2	What do 'U', 'M' and 'C' mean when I type "update"?  Are they
	different for "cvs -n update"?

	"cvs update" merges changes made to the Repository, since your
	last "checkout", "update" or "commit", into your working files.
	You can think of it as "changing your BASE revision."

	"cvs update" prints lines beginning with:

	'U'	after replacing your unmodified file with a different
		revision from the Repository.

	'M'	for two different reasons:

		1. for files you have modified that have not changed in
		   the Repository.

		2. after a merge, if it detected no conflicts.

	'C'	after a merge, if it detected conflicts.

		You will need to remove the conflicts by editing the file.
		Conflicts are surrounded by <<<<< and >>>>> markers.


	"cvs -n update" shows what it *would* do, rather than doing it.
	Or, another way of looking at it, "cvs -n update" displays the
	relationship between your current BASE revisions and the latest
	revisions in the Repository.

	"cvs -n update" prints lines beginning with:

	'U'	for files you have not modified that have changed in the
		Repository.

	'M'	for files you have modified that have not changed in the
		Repository.

	'C'	for files you have modified that have also been changed in
		the Repository.


	See 4C.6 for what the letters mean when merging in from another
	branch.  The output is almost the same for a normal update if you
	consider the Repository as the branch and your working directory
	as the "trunk".


 3P.3	What's the difference between "update" and "checkout"?

	See 3C.4 above.


=3P.4	Why don't I get new files when I execute "update"?

	There are six reasons for nothing to happen during an "update":

	1. Nothing on your branch changed in the Repository.

	   If no one has committed anything to the branch you are working
	   on (normally the Main branch) since the last time you executed
	   "checkout", "update" or "commit", nothing will happen.

	   It's like shouting "xyzzy" or "plugh" in the wrong room.

	2. You have a "sticky" non-branch <tag> or <date> attached to the
	   working files you are trying to "update".

	   At some time in the past you checked out or updated your
	   directory with the "-r <tag>" or "-D <date>" option.  Until you
	   do it again with a different tag or date, or go back to the
	   Main Branch with "update -A", you will never again see any
	   updates.

	3. The ./CVS/Entries.static file exists and you are expecting a
	   new file.

	   If your ./CVS administrative directory contains a file named
	   Entries.Static, no files will be checked out that aren't
	   already in the Entries or Entries.Static file.

	4. You forgot to use the '-d' option and are looking for new
	   directories.

	   If you execute "update" without the '-d' option, it will not
	   create new directories that have been added to the Repository.

	5. You typed "update" instead of "cvs update".

	   And now your disk caches are furiously being flushed by
	   multiple update daemons, destroying performance and proving to
	   management that you need more CPU power.  :-)

	6. Someone backed out the revision CVS thought you had in your
	   working directory, then committed a "replacement".  CVS is now
	   confused because the revision in the Repository matches the
	   revision CVS thinks you already have.  See 3B.6.


#3P.5	Why does "update" say 'M' both for plain modified files and for
	successful (i.e. conflict-free) merges?  Aren't they different?

	A design choice.  Yes, they are different internally, but that
	shouldn't matter.  Your files are in the same condition after the
	"update" as they were before -- a "diff" will display only your
	modifications.  And you are expected to continue onward with the
	normal cycle of "emacs" (a synonym for "edit" in most of the
	civilized world) and "commit".


=3P.6	After a merge ("update" or "update -j"), why doesn't CVS remember
	the conflict and not allow you to commit the result until the
	conflict is resolved?

	Maybe in a future release.  There is a "sticky_conflict" patch you
	might want to look at in the CVS FTP archive.


 3P.7	Is there a feature to tell me what I have changed, added and
	removed without changing anything?

	The command "cvs -n update" will do exactly that.


=3P.8	Why does "cvs update" not flag directories that are not in the
	Repository as it does with new files?

	Design choice or oversight, take your pick.  Directories are
	handled specially.  You can aim "update" at any random directory
	and "update" will traverse the whole directory tree beneath it,
	looking for CVS administrative directories.  When it finds one,
	"update" will perform its "normal" function.

	Maybe a future release will notice a directory not under CVS,
	print a '?' and skip over it.


 3P.9	Why are all my files deleted when I execute "update"?

	You probably executed "update -r <tag>" some time ago, then
	removed <tag> from the Repository files.  "update -r <tag>" will
	delete a file that doesn't contain <tag>.

	A way to fix this is to "cd" into your working directory and
	type:

		cvs update -A

	If you don't want the latest revisions on the Main (or Vendor)
	Branch, then decide what Tag (normal or branch) you want and type:

		cvs update -r <the_tag_you_want>

	Another way to make files disappear is to execute "update -D
	<date>" where <date> is before the date stamped onto the first
	revision in the RCS file.



===============================================
==  Section 4	====	Advanced Topics    ====
===============================================

----------------
-- Section 4A --	Installing CVS
----------------

 **** Questions:

#4A.1	What do I have to do before I install CVS?
 4A.2	How do I configure the CVS programs?
=4A.3	What do I have to install?
-4A.4	How do I work around the merge problems in GNU diff version 2.1
	or later?


 **** Answers:

#4A.1	What do I have to do before I install CVS?

	1. You must decide where to set up a Repository.

	   Though you can construct a Repository tree structure using
	   links and mount points, there must be a single copy of each
	   real file across your entire organization.  You may not "rdist"
	   files and expect to edit both copies.

	   CVS does not support a truly distributed Repository.  You can
	   have multiple Repositories, but each one must be mounted (not
	   copied or "rdist"ed) from a single place onto all machines
	   where it will be used.

	   Initially, a Repository takes about same amount of disk space
	   as the sources you want to put into it, plus a bit of overhead
	   for the RCS files.

	   See Section 4B.  For multiple Repositories, see 4D.14.

	2. You need a directory in everyone's $PATH variable where you can
	   install all the executables.  /usr/local/bin is a common place.

	3. You need some helper tools besides CVS such as "RCS" and a
	   good set of "diff" and "diff3" programs.  See 1B.3 for
	   suggestions.

	4. Make sure you have versions of all the programs mentioned in
	   the "cvs/src/config.h" file.

	5. Though you can probably muddle along without it, you should
	   appoint one or more "Repository Administrators" who will be
	   responsible for maintaining the Repository structure,
	   administrative files and the "modules" interface.

	   Someone at your site should probably be on the info-cvs mailing
	   list.  See 1B.5.


 4A.2	How do I configure the CVS programs?

	1. You should certainly start by reading the README file, the
	   INSTALL files and possibly the Makefiles and "cvsinit" program.

	2. Edit the "config.h" file in the "src" directory.

	   Read it carefully.

	   You will need to specify a number of site-specific pieces of
	   information including the names of a number of functions.

	   Hint1:  You really want to set the DIFF macro to use your
		   version of the GNU diff program with the '-a' option.
		   Ours is set to "gdiff -a".

	   Hint2:  You want to use RCS 5.5 or greater and set the
	   	   "HAVE_RCS5" macro.

	3. Execute the ./configure command.

	4. Type "make".


=4A.3	What do I have to install?

	1. Install the "cvs" executable and "mkmodules" from the CVS
	   sources.  (The man page is useful too.)

	2. Make sure you have versions of all the programs mentioned in
	   the config.h file, most of which are included in a standard
	   Unix system.

	3. Unless you plan to reimplement RCS [:-)], you must install RCS.

	4. Create the Repository (which you planned out in 4A.1) with the
	   "cvsinit" command at the top of the CVS sources.

	5. You'll need to edit the Repository control files created by
	   "cvsinit".

	6. Install any helper programs mentioned in the modules file.


-4A.4	How do I work around the merge problems in GNU diff version 2.1
	or later?

	See 4D.11.


----------------
-- Section 4B --	Setting up and Managing the Repository
----------------

 **** Questions:

=4B.1	What do I do first?  How do I create a Repository?
=4B.2	What are those files in $CVSROOT/CVSROOT?
 4B.3	Is there any other state stored in the Repository besides in the
	$CVSROOT/CVSROOT directory?
 4B.4	How do I put sources into the Repository?
=4B.5	What file permissions should I use on (and in) the Repository?
=4B.6	How do I structure my Repository?
=4B.7	How do I manage the modules file?
 4B.8	Why would anyone use "modules"?  They are too restrictive.  I
	want to be able to select just the files I want to edit.
=4B.9	How do I rename a file or directory?  What are the consequences?
=4B.10	What are "Attic" directories?
 4B.11	Is it OK to remove anything from the Repository?
 4B.12	Can I convert to CVS from RCS without losing my revision history?
=4B.13	Can I move RCS files with branches in them into the Repository?
=4B.14	Can I use raw RCS commands on the Repository?
 4B.15	How do I convert from SCCS to RCS?
=4B.16	How do I limit access to the Repository?
=4B.17	What are the Repository Administrator's responsibilities?
 4B.18	How do I move the whole Repository?
+4B.19	How do I change permissions on a file in the Repository by using
	a CVS command?  (i.e. without using "chmod 777 $CVSROOT/dir/file")


 **** Answers:


=4B.1	What do I do first?  How do I create a Repository?

	First, install all the programs. (See Section 4A.)

	Then create a Repository by executing "cvsinit", which works only
	from within the head of the CVS source directory.  (It needs files
	from the distribution to work.)

	If you want a very primitive Repository and don't want to save a
	history log, refer to modules, or use any of the "info" files for
	logging, pre-commit checks, or editing templates, you can dispense
	with "cvsinit" entirely.  I would advise executing it.

	The cvsinit program will create a short modules file containing
	the module named "CVSROOT".  Execute:

		cvs checkout CVSROOT

	and read the information stored in the files that are checked out.

	You will certainly want to add modules of your own.  Edit the
	"modules" file and add lines to describe the items you want to
	"checkout" by module name.  Here's a short list that could be
	used for storing a small number of GNU and PD sources:

		local	local

		gnu	local/gnu
		emacs	local/gnu/emacs
		cvs	local/gnu/cvs

		public	local/public
		pdprog1	local/public/pdprog1
		pdprog2	local/public/pdprog2

		test	test
		junk	test/junk


	When you are done editing, "commit" the modules file.  If you
	configured CVS to use "dbm", you might have to edit and commit the
	modules file twice, in order to change the pathname of the
	mkmodules program in the modules file.

	Try using the "import" command to insert the "junk" module
	and play around until you are comfortable.



=4B.2	What are those files in $CVSROOT/CVSROOT?

	There are seven Repository control (or "database") files of
	interest in the CVSROOT directory:

	1. commitinfo	contains two columns: 1. a regular expression to
			match against pathnames within the Repository and
			2. a <command> to execute for matching pathnames.

			When you execute "commit", CVS passes the
			Repository pathname for each directory (and the
			files to commit within that directory) to
			<command>.  If <command> exits with a non-zero
			status, the commit is blocked.

			A <command> associated with a pathname of
			"DEFAULT" is executed if nothing else matches.
			Every <command> associated with a pathname of
			"ALL" is executed separately.

	2. rcsinfo	contains the same first column as commitinfo, but
			the second column is a template file for
			specifying the log entry you are required to enter
			for each commit.

			"DEFAULT" and "ALL" work the same as in the
			commitinfo file.

	3. editinfo	contains the same two columns as commitinfo, but
			the <command> in the second column is intended to
			do some consistency checking on the commit log.

			"DEFAULT" works as in commitinfo.

	4. loginfo	contains the same two columns as commitinfo, but
			the <command> is expected to read a log message
			from its standard input.  The <command> can do
			anything it wants with the log information, but
			normally it is appended to a log file or sent to
			mailing lists.

			"DEFAULT" & "ALL" work the same as in commitinfo.

	5. cvsignore	contains "ignore" patterns that are added to the
			built-in ignore list.  See 2D.10.

	6. history	contains a stream of text records, one for each
			event that the "history" command is interested
			in.  Though the contents of the history file can
			be read, it is intended to be read and displayed
			by the "history" command.

	7. modules	contains the "modules" database.  See 1D.11, 2C.7,
			4B.7 and 4B.8 for more details.


 4B.3	Is there any other state stored in the Repository besides in the
	$CVSROOT/CVSROOT directory?

	Only in the RCS files.  The Repository holds exactly two things:
	the tree of RCS files (each usually ending in ",v") and the
	CVSROOT directory described above.


 4B.4	How do I put sources into the Repository?

	There are three main ways to put files in the Repository:

	1. Use the "import" command described in Section 3H.

	   This method is the fastest way to put trees of new code into
	   the Repository and the *only* way to handle source releases
	   from a 3rd party software vendor.

	2. Use "add" followed by "commit".

	   This is how to add new files and directories to the Repository,
	   one at a time.

	3. You can move RCS files directly into the Repository.

	   It would probably be a good idea to create directories to hold
	   them.


=4B.5	What file permissions should I use on (and in) the Repository?

	If you run a completely open environment (which usually means that
	you don't have, or don't want to waste, the time to deal with it):

	   - Set all directory permissions to 777.

	   - Have everyone set their umasks to 0.

	   (BTW, I don't suggest this.  It am merely reporting it.)


	If you are a normal Unix shop and want to use groups effectively:

	   - Set all the directory permissions in the Repository to 775.
	     (If you are using a system that handles both System V and BSD
	      filesystems, you might have to set the permissions to 2775.)

	   - Change all the groups on the directories to match the groups
	     you want to write to various directories.

	   - Make sure every user is in the appropriate groups.

	   - Have everyone set their umask to 002.


	If you don't want non-group members to even read the files, do the
	above, but change:

	   - Repository directory permissions to 770. (or 2770)

	   - umasks to 007.


	If you work in an environment where people can't be trusted to
 	set their "umask" to something reasonable, you might want to set
 	the umask for them:

		mv /usr/local/bin/cvs /usr/local/bin/cvs.real
		cat > /usr/local/bin/cvs
		#!/bin/sh
		umask 2		# Or whatever your site standard is.
		exec /usr/local/bin/cvs.real ${1+"$@"}
		^D

	[[Future versions of CVS might sprout a "umask" configuration
	variable.]]


=4B.6	How do I structure my Repository?

	The Repository holds your software.  It can be all interrelated
	or it can be a bunch of separately managed directories.

	How you break a whole system down into its component parts, while
	defining interfaces between them, is one aspect of "Software
	Engineering", a discipline that requires the study of dozens of
	strange and wonderful areas of the computer and management worlds.

	CVS provides a way to keep track of changes to individual files,
	a way to "tag" collections of files, and a way to "name"
	collections of files and directories.  That's all.  Everything
	else is in the way you apply it.

	In other words, you should structure your Repository to match your
	needs, usually tied in with the other tools you use to build,
	install and distribute your work.  Common needs include the
	ability to:

	  - mount (or automount) directories from different
	    places in your organization.
	  - check out just what you need and no more.
	  - check out multiple sections in a fixed relation to each other.
	  - check out large sections to match the assumptions built into
	    your build system. (Makefiles?)

	In my opinion, you should start small and keep everything in one
	tree, placing each major sub-system into a separate directory.
	Later, when you know what you are doing, you can make it more
	sophisticated.


=4B.7	How do I manage the modules file?

	An equivalent question might be, "How do I structure my sources?"
	This can be a difficult question in that it is not purely
	technical.

	Generally you want to think about what pieces of your system need
	to be checked out together, built as one system or tagged
	consistently.  You should certainly make module names that
	correspond to complete, buildable collections that you would tag
	and release as one "product".  It is also convenient to create
	module names for small sections containing files that will usually
	be worked on at the same time by the same person.

	Once you have defined the structure of your work, you can usually
	see how to lay it out in a Repository.  After that the modules
	file is easy.  You set up module names and aliases to match what
	you need to check out by name.  If you like relative directories,
	it is possible, but not recommended, to work completely without a
	modules file.  See 1D.11 and 2C.7.


 4B.8	Why would anyone use "modules"?  They are too restrictive.  I
	want to be able to select just the files I want to edit.

	Any form of structure is restrictive.  If you believe that total
	chaos is a viable working paradigm, or if you believe you can keep
	track of the interrelations between all portions of your
	Repository in your head, then you can do what you please.

	If you believe that systems of files require management and
	structure, then the "modules" idea is very useful.  It is a way
	to impose a naming scheme on a tree of files, a naming scheme that
	can be simpler than a large list of relative pathnames.

	The "modules" file represents a published interface to the
	Repository set up by your Repository Administrator.  If s/he did a
	creditable job, the modules offered will be internally consistent
	and will smoothly interact with the rest of your environment.


=4B.9	How do I rename a file or directory?  What are the consequences?

	In CVS 1.3 there is no single CVS "rename" command.

	See 2C.4 for the suggested way to rename a file or directory.

	The rest of this section covers some of the consequences of
	renaming.

	A "renaming database" has been proposed that would keep track
	of name changes so that "update -r <tag>" would continue to
	work across the renaming.  But as it stands, you have to pick
	one of the following options:

	1. Use the technique described in 2C.4.  (For each file, duplicate
	   the file in the Repository, "remove" the old version so it
	   winds up in the Attic and strip all Tags off the new version.)

	   - "update -r <tag>" produces the correct files.

	   - The duplicated revision history can be slightly misleading.

	   - A plain (i.e. without the "-r <tag>") "checkout" or "update
	     -d" will create directories "renamed" this way, but you can
	     delete it and a plain "update" won't bring it back.


	2. Move the files and directories in the Repository to the new
	   names.

	   - You save the revision history under a different file name.

	   - You save a little space.

	   - "update -r <tag>" produces the wrong files or directories.

	     This is not a good general solution, but if you plan never to
	     look back (someone may be gaining on you!), it is sometimes a
	     useful notion.

	     If you are clever with Makefiles, you might be able to rework
	     them to handle either the new or old names, depending on
	     which ones exist at the time.  Then you can move an old <tag>
	     onto the new, more sophisticated, revision of the Makefile.
	     (Yes, this changes the "released" file if <tag> indicates a
	     release.  But it is an option.)

	   - Important Note:  If you rename a directory, you must rename
	     the corresponding directory in every checked-out working
	     directory.  At the same time, you must edit the pathname
	     stored in the ./CVS/Repository file within each of the moved
	     directories.

	     The easiest way to move a lot of directories around is to
	     tell everyone to remove their working directories and check
	     them out again from scratch.

	   - The file exists in the working directory and in the
	     ./CVS/Entries file, but not in the Repository.  For the old
	     file, "update" prints:

		cvs update: xyz.c is no longer in the repository

	     and deletes the file.  If the file was modified, "update"
	     prints:

		cvs update: conflict: xyz.c is modified but
					no longer in the repository
		C xyz.c

	     and leaves the file alone.  In the new directory, you see:

		U xyz.c

	     as you would if someone else executed "add" and "commit".


	3. For each file, copy the working file to a new name, "remove"
	   the old file and "add" the new one.  Since there is no way (in
	   CVS 1.3) to remove a directory, this only works for files.

	   - This is what most people think of first.  Without a "rename"
	     command, the remove/add technique seems obvious.

	   - You lose the connection of your new working file to its past
	     revision history.


=4B.10	What are "Attic" directories?

	When you use the "remove" command on a file, CVS doesn't delete
	the file, it only registers your desire to delete it.

	When you "commit" a removed file, CVS moves the Repository's
	matching RCS file into a sub-directory named "Attic" within the
	Repository.

	Attic files are examined when the '-r' or '-D' option is used
	on "checkout" or "update".  If the specified revision, tag or
	date matches one on a file in the Attic, that file is checked out
	with the others.

	You can think of the Attic as a sort of dead branch, which is only
	looked at when you refer to a <tag> or <date>.


 4B.11	Is it OK to remove anything from the Repository?

	In general, removing anything from the Repository is a bad idea.
	The information in a deleted object is lost forever.  There are
	many ways to skip over files, directories and revisions without
	deleting them.

	Here are some of the consequences of removing the following things
	stored in the Repository:

	1. CVSROOT files  (Repository control files)

	   The Repository will work without any of them, but you should
	   understand what you are losing by deleting them.  See 4B.2.

	2. Revisions

	   The only way to remove revisions is to use the "admin -o"
	   command (or the equivalent RCS command "rcs -o").

	   They are lost forever.  Any tags formerly attached to deleted
	   revisions are now pointing into Outer Space.

	3. Files

	   You should not remove a file unless you truly never want to see
	   it again.  If you want to be able to check out an old revision
	   of this file, use "cvs remove" instead.

	4. Tags

	   Tags take up little space and you can't recover from deleting
	   them.  If you depend on tags for releases you will lose vital
	   information.

	5. Directories

	   There is no Attic for directories, so the only way to remove
	   them is to use "rm -r".  They are gone forever.

	   If you delete (or move) a directory, all checked-out versions
	   of that directory will cause CVS to halt.  You'll have to visit
	   each checked-out directory and remove the matching working
	   directory by hand.

	6. Attic files

	   The "remove" command sends files to the Attic.  To really
	   delete them, you have to go into the Attic and use "rm".

	   If a file in the Attic has a Tag on it that you might ever want
	   to check out again, you probably don't want to delete it.

	7. Lock files (named: "#cvs.[wr]fl.<pid>")

	   These are lock files.  If you are getting "lock" errors and
	   the dates on the lock files indicate that they are old, you can
	   delete them.

	   Deleting lock files still in use by a CVS process might produce
	   unusual errors.


 4B.12	Can I convert to CVS from RCS without losing my revision history?

	Yes, you can simply move (or copy) your RCS files into a directory
	within the Repository, check out that directory and start working.


=4B.13	Can I move RCS files with branches in them into the Repository?

	Yes, but they may not work if you created branches in a way that
	conflicts with CVS's assumptions:

	1. You can't use .0. branches.  (They are reserved for "Magic"
	   branch tags.)

	2. If you use branch 1.1.1, you can't use the Vendor branch.

	You can use other RCS branches under CVS.  There is no need to
	create "magic" branch tags because the physical branch already
	exists.


=4B.14	Can I use raw RCS commands on the Repository?

	You can use raw rcs commands directly on the Repository if you
	take a little care.  The Repository itself contains no "CVS state"
	(as opposed to RCS revision histories) outside the CVSROOT
	directory.

	But using raw RCS commands to change branches, tags or other
	things that CVS depends on may render the files unusable.

	See 4D.7 on RCS/CVS sharing of the Repository and Section 3B on
	the "admin" command.


 4B.15	How do I convert from SCCS to RCS?

	You'll have to execute something like "sccs2rcs" (in the CVS
	contrib directory) on every file.  Then you can move the resulting
	RCS files into the Repository as described above.


=4B.16	How do I limit access to the Repository?

	There are all sorts of ways to restrict access to Repository
	files, none of which are hooked directly into CVS.  You can:

	1. Set Unix groups and permissions.  See 4B.5.

	2. Try the "setgid" trick described in 4D.16.

	3. Catch every commit using the "commitinfo" file.

	4. Try to use the RCS access control lists, though I don't
	   think CVS will handle them cleanly.

	5. Edit the source code to CVS.


=4B.17	What are the Repository Administrator's responsibilities?

	Generally, the Administrator should set "policy", create the
	Repository and monitor its size and control files.

	Some specific responsibilities include:


	1. Examining the Repository once in a while to clean up:

	   a. Trash files left by misguided developers who mistake the
	      Repository for a working directory.

	   b. Non-RCS files.  Other than the files CVS needs in the
	      $CVSROOT/CVSROOT directory, everything in the Repository
	      should be "under" CVS.

	   c. Lock files (both CVS '#*' and RCS ',*' files) left around
	      after crashes.
	      
	   d. Wrong permissions, groups and ownerships.

	   e. Locked files. (RCS locks, that is.)

	   f. Attic files that should never have been under CVS at all.
	      Don't blindly delete files from Attic directories -- they
	      were mostly put there (via the "cvs remove") for a reason.
	      Files that should be deleted are binary files (e.g. '*.o',
	      'core', executables) that were mistakenly inserted by
	      "import -I !".

	2. Maintaining the modules file.

	3. Maintaining the other Repository control files: commitinfo,
	   loginfo, rcsinfo and editinfo files.

	4. Storing site-specific ignore patterns in the "cvsignore" file.

	5. Pruning the history file every once in a while.  (Try the
	   "cln_hist.pl" script in the "contrib" directory.)

	6. Staying aware of developments on the info-cvs mailing list and
	   what is available in the FTP archive.

	7. Run "ps ax" once in a while and kill off any "update"
	   programs not running as "root".  It is too easy to leave the
	   "cvs" off the front of the "cvs update" command. 

	8. Executing monitor programs to check the internal consistency of
	   the Repository files.  Ideas:

	   a. Files that have a default RCS branch that is not 1.1.1
	      (From an abuse of "admin -b".)

	   b. Files that have only Revisions 1.1 and 1.1.1.1, with a
	      default branch of "MAIN".  (From an abuse of "admin -o".)

	   c. Existing branch tags and various branch consistency checks.



 4B.18	How do I move the whole Repository?

	The Repository itself contains pathnames only within the files in
	the CVSROOT directory.  If helper functions in the modules file or
	logging programs executed out of the loginfo file point into the
	Repository, you'll have to change the pathnames to point to the
	new Repository location.

	The main change you'll have to make is to all the ./CVS/Repository
	files in the checked-out working directories.

	You have four choices:

	1. If you can avoid changing $CVSROOT by using a symbolic link or
	   mount point you don't have to do anything else.

	   If you must change $CVSROOT, you must also tell everyone to
	   change the CVSROOT environment variable in all running shells
	   and in their '.' files where it is set.  Then pick one of the
	   other three options that follow:

	2. If all ./CVS/Repository files in all working directories
	   contain relative pathnames, you don't have to do anything else.

	3. Have everyone "release" or delete their working directories
	   (after committing, or just saving, their work) and check them
	   all out again from the new Repository after the move.

	4. Use a PERL or shell script to run through all the
	   ./CVS/Repository files and edit the values in the files.


+4B.19	How do I change permissions on a file in the Repository by using
	a CVS command?  (i.e. without using "chmod 777 $CVSROOT/dir/file")

	When you first "import" or "add"/"commit" a file, the read and
	execute bits on the Repository file are inherited from the
	original source file, while the write bits on the Repository file
	are are turned off.  This is a standard RCS action.

	After that, there is no way to alter the permissions on a file in
	the Repository other than by changing the Repository file
	directly.

	Whenever you "checkout" the file or retrieve a new revision via
	"update" (or after a "commit"), your working file is set to match
	the permissions of the Repository file, minus any "umask" bits you
	have set.



----------------
-- Section 4C --	Branching
----------------

 **** Questions:

 4C.1	What is a branch?
=4C.2	Why (or when) would I want to create a branch?
=4C.3	How do I create and checkout a branch?
 4C.4	Once created, how do I manage a branch?
 4C.5	Are there any extra issues in managing multiple branches?
 4C.6	How do I merge a whole branch back into the trunk?
 4C.7	How do I merge changes from the trunk into my branch or between
	branches?
 4C.8	How do I add a new file to a branch?
=4C.9	How do I know what branch I'm (working) on?
 4C.10	Do I really have to know the name of the branch I'm working on?
 4C.11	How do I refer to the revision where I branched so I can see
	what changed since the Branch Point on another branch?
 4C.12	Why didn't the command "cvs admin -bBRANCH1 *" create a branch?
 4C.13	Is it possible to set the "default CVS branch" for everyone?
=4C.14	How do I perform a large merge?
 4C.15	Is a Vendor merge any different from a branch merge?
+4C.16	How do I go back to a previous version of the code on a branch?
+4C.17	Why do I get the latest files on the branch when I tried to
	"update -r <tag>"?


 **** Answers:

 4C.1	What is a branch?

	Unfortunately, the word "branch" is an overloaded technical term.
	It is used in too many different ways in three categories.  It
	might help to understand some of the issues by going through
	the categories:

	1. How Humans use the word "branch":

	   Most development starts with everyone working on the same
	   software, making changes and heading toward a single goal.
	   This is called something like "Main Line Development".  Note
	   that though many people do main line development on CVS's
	   "Main Branch", that is a choice, not a requirement.

	   After a release or when one or more developers want to go off
	   and work on some project for a while, the Software Engineers
	   assigned to deal with large software issues generate a "Branch
	   in Development" to support the release or project.  (Keep in
	   mind that a programmer is no more a Software Engineer than a
	   carpenter is a Civil Engineer.)

	   Essentially, the word "branch" implies a way to allow
	   simultaneous development on the same files by multiple people.

	   The above terms are human-oriented.  They refer to actions
	   that people would like to take.  They do *not* imply any
	   particular implementation or set of procedures.  Branches in
	   development can be supported in many different ways.


	2. How CVS uses the word "branch":

	   CVS uses the word "branch" in a number of ways.  The two most
	   important are:

	      - The vendor branch holds releases from (normally) an
		outside software vendor.  It is implemented using a
		specific RCS branch (i.e. 1.1.1).

	      - The "Main Branch", which normally holds your "Main Line
		Development", but is defined as the collection of
		revisions you get when you "checkout" something fresh, or
		when you use the '-A' option to "update".

	   Important Note: The CVS "Main Branch" is *not* the same as
	   the RCS concept with the same name.  If you are using Vendor
	   Branches, files you have never changed are on three branches at
	   the same time:

		- The RCS 1.1.1 branch.
		- The CVS Vendor branch.
		- The CVS "Main Branch".

	   The concepts overlap, but they are not equivalent.

	   In referring to CVS, "branch" can be used in four other ways:

	      - A CVS working directory satisfies the definition of
		"branch" for a single developer -- you are on a "virtual
		branch" that does not appear in any of the RCS files or
		the CVS control files.

	      - The CVS "default branch" is the Repository source for the
		collection of files in your working directory.  It is
		*not* the same as the RCS "default branch".  Normally the
		CVS default branch is the same as the CVS Main branch.  If
		you use the "-r <branch_tag>" option to the "checkout"
		command, you will record a "sticky" tag that changes your
		default branch to the one you checked out.

	      - A "magic" branch can be a branch that hasn't happened
		yet.  It is implemented by a special tag you can check out
		that is not attached to a real RCS branch.  When you
		commit a file to a magic branch, the branch becomes real
		(i.e. a physical RCS branch).

	      - And, of course, CVS uses "branch" to indicate a
		human-oriented "branch in development".

	3. How RCS uses the word "branch":

	   - The RCS "Main Branch" (Synonym: "The Trunk") contains a
	     series of two-part revision numbers separated by a single '.'
	     (e.g. 1.2).  It is treated specially and is the initial
	     default branch.  (The default default?)

	   - The RCS "Default" branch starts out attached to the RCS "Main
	     Branch".  For RCS purposes, it can be changed to point to any
	     branch.  Within CVS, you *must*not* alter the RCS default
	     branch.  It is used to support the CVS idea of a "Main
	     Branch" and it must either point to the RCS Main Branch, or
	     the Vendor Branch (1.1.1) if you haven't made any changes to
	     the file since you executed "import".


=4C.2	Why (or when) would I want to create a branch?

	Remember that you can think of your working directory as a
	"branch for one".  You can consider yourself to be on a branch
	all the time because you can work without interfering with others
	until your project (big or small) is done.

	The four major situations when should create a branch are when:

	1. You expect to take a long enough time or make a large enough
	   set of changes that the merging process will be difficult.

	2. You want to be able to "commit" and "tag" your work
	   repeatedly without affecting others.

	   If you ever think you need Source Control for your own work,
	   but don't want your changes to affect others, create a private
	   branch.  (Put your username in the branch tag, to make it
	   obvious that it is private.)

	3. You need to share code among a group of developers, but not the
	   whole development organization working on the files.

	   Rather than trying to share a working directory, you can move
	   onto a branch and share your work with others by "committing"
	   your work onto the branch.  Developers not working on the
	   branch won't see your work unless they switch to your branch or
	   explicitly merge your branch into theirs.

	4. You need to make minor changes to a released system.

	   Normally a "release" is labeled by a branch tag, allowing later
	   work on the released files.  If the release is labeled by a
	   non-branch tag, it is easy to add a branch tag to a previously
	   tagged module with the "rtag" command.  If the release is not
	   tagged, you made a mistake.  Recovery requires identifying all
	   revisions involved in the release and adding a tag to them.


=4C.3	How do I create and checkout a branch?

	Suggested short form:

	  1. Attach a non-branch tag to all the revisions you want to
	     branch from. (i.e. the branch point revisions)

	  2. When you decide you really need a branch, attach a branch tag
	     to the same revisions marked by the non-branch tag.

	  3. "Checkout" or move your working directory to the branch.


	Suggested short form using modules:

	  A1.	cvs rtag <branch_point_tag> module
	  A2.	cvs rtag -b -r <branch_point_tag> <branch_tag> module
	  A3.	cvs checkout -r <branch_tag> module


	Suggested short form using your working directory, which contains
	the revisions of your working files you want to branch from:

	  B1.	cvs tag <branch_point_tag>
	  B2.	cvs rtag -b -r <branch_point_tag> <branch_tag> module
	  B3.	cvs update -r <branch_tag>


	The <branch_tag> is an unusual creature.  It labels a branch in a
	way that allows you to "checkout" the branch, to "commit" files to
	the end of the branch and to refer to the end of the branch.  It
	does not label the base of the branch (the branch point).

	Step #1 applies a non-branch tag to all the branch point revisions
	in the module/directory.  Though this is not strictly necessary,
	if you don't add a non-branch tag to the revisions you branch
	from, you won't be able to refer to the branch point in the
	future.

	Between steps 1 & 2 you may commit files and the result is the
	same because "rtag -r <oldtag> <newtag>" applies <newtag> to the
	same revision that <oldtag> is attached to.  You can use this
	technique to avoid attaching *any* branch tags until you need
	them.

	Step B2 has two important corollaries:

	     1. If you plan to create the branch tag before committing
		anything in your working directory, you can use "cvs tag
		-b <branch_tag>" instead of the "rtag" command.

	     2. If you have trouble figuring out what "module" to use,
		remember that "module" can also mean "relative path within
		the Repository."  If that doesn't help, you can aim it at
		whatever parent directories you believe will cover all
		your files.  You can even aim it at the whole Repository
		($CVSROOT), if you have to.  It might take some extra
		time, but assuming that your Tag is a unique string and
		you don't use the '-f' option to "rtag -r", "rtag" will
		only add a Tag to files in which it actually *finds* the
		earlier Tag.


	Step 3 may occur any time after step 2.  Unless you explicitly
	remove them with "tag -d", the Tags are permanent.


	There are two obvious ways of to choose the <branch_point_tag> and
	<branch_tag> names.  Since the <branch_tag> is typed by any
	developer who wants to work on the branch, you should make it mean
	something to them.

	Style #1 presumes that the simple version string refers to a set
	of designed, documented or promised features, not to a specific
	set of files.  In this case, you tag the branch with the generic
	Version string and assume that whenever you refer to "Version",
	you want the "latest" set of files associated with that Version,
	including all patches.  (You can substitute what ever you like for
	"bp_", as long as your <branch_point_tag> is some modification of
	the <branch_tag>.)

	   	<branch_point_tag>	Matching <branch_tag>

		bp_V1_3			V1_3
		bp_Release2-3-5		Release2-3-5
		bp_Production4_5 	Release4_5 


	Style #2 presumes that the simple version string refers to the
	specific set of files used to construct the first release of
	"version".  In this case, you tag the branch-point revisions with
	the generic Version string and assume that whenever you refer to
	this Version, you want the original set of released revisions.  To
	get the latest patched revisions of the release, you refer to the
	branch tag "latest_<branch_point_tag>". (You can substitute what
	ever you like for "latest_", as long as your <branch_tag> is some
	modification of the <branch_point_tag>.)

	   	<branch_point_tag>	Matching <branch_tag>

		V1_3			latest_V1_3
		Release2-3-5		latest_Release2-3-5
	 	Release4_5 		latest_Production4_5


	In both styles you can find out what you had to change since the
	original release of this Version by typing:

	    cvs diff -r <branch_point_tag> -r <branch_tag>

	For Style 1, this is:

	    cvs diff -r bp_<branch_tag> -r <branch_tag>

	For Style 2, this is:

	    cvs diff -r <branch_point_tag> -r latest_<branch_point_tag>


	Notes:

	- The "-r <tag>" option tells CVS to attach a "sticky tag" to
	  working directory (in ./CVS/Tag) and the checked-out files (on
	  each line of ./CVS/Entries).

	- A "sticky" <tag> (including a <branch_tag>) causes most CVS
	  commands to act as if "-r <tag>" were on the command line.

	- A "sticky" <branch_tag> indicates that the working directory
	  (and working files) are "on the branch".


 4C.4	Once created, how do I manage a branch?

	The most important thing you should know about managing a branch
	is that the creation of a branch is not a lightweight act.  When
	you create a branch, you must also create a set of procedures to
	keep track of it.

	Specifically, you must:

	- Remember that the branch exists.  (This is non-trivial if you
	  create a lot of them.)

	- Plan when to merge it back into the main line of development.

	- Schedule the order that multiple branch merges are to be done.

	- If you ever intend to merge branches into each other, instead of
	  limiting merges of branch work back into the "main line", you
	  must keep careful track of which parts of which branches have
	  merged into which other branches.


	The simplest way to deal with branches is to limit their number,
	"collapse" them back into the main line as quickly as is
	reasonable and forget them.  If a group wants to continue working,
	tell them to create another branch off the fully merged main line.

	Remember that CVS is just a tool.  Over time, it will probably
	handle branching better, requiring less careful attendance.
	But no matter how good it becomes, the whole idea of "branching"
	is a complicated management problem.  Don't take it lightly.


 4C.5	Are there any extra issues in managing multiple branches?

	If you plan to split from the "main line" and merge back after a
	time, the only problem will be scheduling the order of branch
	merges.  As each branch is merged, the main line must be rebuilt
	and tested.  Merging multiple branches (i.e. "lines of
	development") before building and testing creates more problems
	than you are ready for.

	If you plan to collapse some branches into others, then move the
	combined branches back into the main line, you have to be careful
	with the revisions and tags you hand to your "update -j"
	command, but it shouldn't be much trouble.

	If you plan to allow every branch to incrementally take the work
	done on other branches, you are creating an almost insurmountable
	bookkeeping problem.  Every developer will say "Hey, I can
	handle taking just this little bit," but for the system as a
	whole it is disaster.  Try it once and see.  If you are forced
	into this situation, you will need to keep track of the beginning
	and end points of every merge ever done.  Good Luck.


 4C.6	How do I merge a whole branch back into the trunk?

	If you don't have a working directory, you can checkout and merge
	in one command:

		cvs checkout -j <branch_tag> <module>
		cd <module>

	If you already have a working directory:

		cd <working_directory>
		cvs update	<== Optional, to bring it up to date.
		cvs update -j <branch_tag>

	CVS will print lines beginning with

	'U'	for files that you hadn't changed, but the branch did.

	'M'	for files that you changed and the branch didn't
	  	*and* for files that you both changed that were merged
		without overlaps.  (This overload is unfortunate.)

	'C'	for files that you both changed in a way that conflicts
		with each other.

	You need to go edit all the 'C' files and clean up the conflicts.
	Then you must commit them.


 4C.7	How do I merge changes from the trunk into my branch or between
	branches?

	The idea is similar to the above, but since CVS doesn't treat the
	main branch like other branches, you'll have to be more precise.

	Check out or "update" the files you want to merge into.

	Identify the two tags on the branch you want to merge from.
	(Revisions don't work too well because the same revision doesn't
	 mean the same thing in different files.)  Then type:

		cvs update -j <tag1> -j <tag2>

	You can use a <branch_tag> to refer to the latest revision on the
	branch, but there is no built-in way to refer to the branch point.


	An alternative to merging is to identify a single revision you
	want, grab it by using "update -p" and commit it.  If you do
	merges later, you'll get overlaps, but you get your file.


	In the future, (but not yet) merging from the main branch will
	look something like this:

		cvs update -j MAIN
		cvs commit -m "Log message"


 4C.8	How do I add a new file to a branch?

	The obvious technique is broken in CVS 1.3.  This is the way it is
	supposed to work:

	You are in a directory checked out (or updated) with the "-r
	<branch_tag>" option.   To add <file> to the branch named
	<branch_tag> you type:

		cvs add <file>
		cvs commit <file>


	Until the next release appears, you must explicitly specify the
	branch_tag:

		cvs add <file>
		cvs commit -r <branch_tag> <file>

	One not so obvious side-effect is that the file ends up in the
	Attic.  It wasn't added to the Main Branch so it doesn't show up
	in the main part of the Repository, only in the Attic.

	You can add it to the Main Branch and branch off from there onto
	the side-branch this way:

	1. Move the working file back to the main branch:

		cvs update -A <file>

	2. Add the file "normally":

		cvs add <file>
		cvs commit <file>

	3. Branch-tag the file using the same <branch_tag> as you did on
	   all the other files in your directory:

		cvs tag -b <branch_tag> <file>

	4. And move the file back onto the branch:

		cvs update -r <branch_tag> <file>


=4C.9	How do I know what branch I'm (working) on?

	Type:
		cvs status

	and look at the "Sticky Tag" field for each file.  If:

	1. The *same* tag is on *every* file in your working tree, *and*
	2. That tag matches the contents of the ./CVS/Tag file, *and*
	3. That tag is a branch tag, 

	then you know what branch you are working on.  You can get sticky
	Tag information directly from the ./CVS/Entries file instead of
	"cvs status".

	If all the sticky Tags don't agree, then your directory is
	temporarily inconsistent.  This is a feature allowing you to make
	changes (or perform merges) to individual files on multiple
	branches without checking out the whole directory.

	The sticky Tag on each file in the ./CVS/Entries file (as
	displayed by the "status" command) indicates what branch the
	working file is on.  New files should be added to the Tag stored
	in ./CVS/Tag, but they are not.  See the above question on adding
	a new file to a branch.

	To force your entire working directory onto the same branch, type:

		cvs update -r <branch_tag>


 4C.10	Do I really have to know the name of the branch I'm working on?

	If a developer can't be relied on to know what branch of
	development to work on, then either the developer's manager
	isn't planning branches properly or the developer has serious
	problems.

	I have found that one of the hardest concepts to get across to
	developers (and some managers) is that "a branch in development"
	(as opposed to the use of RCS branches to support some other
	scheme) is a heavyweight act.  Every time you create a real branch
	in development, you must spawn a set of managerial procedures and
	a schedule by which you plan to merge each branch into each other
	branch.  Unless you plan to keep it simple and collapse (by
	merging and forgetting) branches quickly, they are not to be
	created lightly.

	In other words, if there aren't group meetings in which the branch
	to be worked on is a major topic of discussion, then the group is
	not managing branches properly.

	We created a couple major branches a few months ago and even the
	customer service people refer to the "XYZ branch" as a shorthand
	for "continuing development on the XYZ project".


 4C.11	How do I refer to the revision where I branched so I can see
	what changed since the Branch Point on another branch?

	Given the current <branch_tag> format, there is no direct way to
	refer to the branch point, which is more useful in many ways
	than referring to the branch, which always refers to the latest
	revision on the branch.

	When CVS adds a branch tag, it attaches an RCS symbol to a
	non-existent revision number containing the revision number of the
	branch point as a prefix.  (See Section 3O, on the "tag" command.)
	RCS can't use the CVS magic branch tag and many of the CVS
	commands can't refer to it.

	To be certain of your ability to refer to a branch point, you must
	create a "branch point" tag at the same time as the Branch tag.
	See 4C.3.


 4C.12	Why didn't the command "cvs admin -bBRANCH1 *" create a branch?

	Because your command creates an RCS branch, not a CVS branch.  See
	the above discussion on branches.  RCS branches are used to
	support CVS branches, but they are not the same.  You can't act as
	if you have direct control over the RCS files.

	The "admin" command was placed there as a convenience to allow
	you to execute raw "rcs" commands on the Repository, taking
	advantage of CVS's ability to find the files in the Repository.

	But you have to remember that you are using RCS commands on a
	CVS Repository, which is not generally safe unless you know
	exactly what CVS depends on.

	For one thing, CVS insists on control of the default branch.  It
	is set either to the Main branch or the Vendor branch depending
	on whether you have changed the Vendor's code.  If you change
	the default branch, you are monkeying with the internals and
	you will get unexpected results.

	To set your "default CVS branch" to BRANCH1, you must use
	"checkout" or "update" with the "-r BRANCH1" option.  Then you
	have changed CVS's idea of your "default branch", which has
	little to do with RCS's default branch.


 4C.13	Is it possible to set the "default CVS branch" for everyone?

	No.  It doesn't work that way.

	When using CVS, all administrative information (such as what
	branch you checked out) is stored in CVS sub-directories, local to
	the user.  There is no global state, other than the description
	and logging files in $CVSROOT/CVSROOT.

	You tell "checkout" or "update", via the "-r <tag>" option,
	what branch you want to check out.  The default is CVS's "Main
	Branch".

	I don't see a problem in *designing* a new way to indicate what
	branch you get by default, instead of the main one, but that's not
	how it currently works.


=4C.14	How do I perform a large merge?

	Large merges require a bit more planning to be able to track
	what has happened in the inevitable cases where something goes
	wrong.  No tool can make a "merge" make perfect sense.

	Though you can handle the details in many different ways, the two
	ends of the spectrum of merge techniques are: gonzo and paranoid.

	The gonzo method assumes that you know everything about your
	sources so that recovery from failures is "just a matter of
	typing."  You created the branch this way:

		cvs checkout <module>
		cd <module>
		cvs tag -b <branch_tag>
		cvs update -r <branch_tag>
		>>> Edit away.
		cvs commit		<<== Onto branch

	Now you want to merge your branch back into the Main branch, you
	are certain you can make it work, or at least detect all the
	failures, so you dive in and hack away: (For simplicity, we will
	assume you are collapsing (i.e. merging and forgetting) a
	side-branch into the Main branch from your single working
	directory.)

		cvs update -A
		cvs update -j <branch_tag>
		>>> Edit the 'C' files and remove the overlaps.
		>>> Edit some more to make it all compile and work.
		cvs commit

	Looks simple.  For more details on the output from the
	"update -j" command, see 3P.2 and 4C.6.

	(Note: You could also checkout a whole new working directory and
	 perform the merge at the same time by replacing the two update
	 commands with "cvs checkout -j <branch_tag> <module>".


	The paranoid way is more difficult, but it can catch all sorts of
	problems.  You created the branch this way:

		cvs checkout <module>
		cd <module>
		cvs tag <branch_point_tag>
		cvs tag -b <branch_tag>
		cvs update -r <branch_tag>
		>>> Edit away.
		cvs commit		<<== Onto branch

	The extra tag command places a non-magic tag on the Branch Point,
	an act that makes it easier to do "diffs" later.  Now we decide
	to perform the merge:

		cvs tag <latest_on_branch_tag>
		cvs update -A
	 *1* 	cvs diff -r <branch_point_tag> -r <latest_on_branch_tag>
		>>> *1* holds all the changes on the branch.
	 *2*	cvs diff -r <branch_point_tag> -r HEAD
		>>> *2* holds the changes on the trunk since branching.
		cvs tag <premerge_tag>
		cvs update -j <branch_tag>
		>>> Edit the 'C' files and remove the overlaps.
	 *3*	cvs diff
		>>> Verify that *3* matches *1*, except for line numbers
		     and overlaps.
		cvs commit
		cvs tag <just_merge_changes_tag>
		>>> Edit some more to make it all compile and work.
		cvs commit
		cvs tag <after_merge_cleanup_tag>


	The reason *3* and *1* match so closely is that they are the
	differences between two pairs of starting points and ending points
	after the same data was inserted.  If they are significantly
	different, you will want to figure out why.

	NOTE: You will have to tell everyone to stay the hell out of the
	Repository while you do this.  If they commit something while you
	are in the middle of a merge, your job will be much more
	difficult.  If they "update" at the wrong time, their work will
	be randomized until you finish.  It's better to call a halt.


 4C.15	Is a Vendor merge any different from a branch merge?

	No.  In most ways, a Vendor branch is exactly the same as any
	other branch.  In a Vendor merge, the data is append to the branch
	by the "import" command, rather than by hand-editing, but the
	merge process is the same.

	See the "import" command in section 3H.


+4C.16	How do I go back to a previous version of the code on a branch?

	You can avoid digging into RCS revision numbers (executing "update
	-r <rev>" on each file) by trying one of these:

	1. Use non-branch tags as you normally would.  Non-branch tags
	   attach to specific revisions, so a "tag <tag>" command would
	   mark the revisions you have in your working directory, which
	   are on your branch.  If you need to retrieve them, use "update
	   -r <non-branch-tag>"

	   Doing this overrides the sticky <branch_tag> attached to your
	   working directory with a non-branch tag, which means you won't
	   be able to commit until you again move forward to the end of
	   the branch with "update -r <branch_tag>".

	2. Use the "update -r <branch_tag>:<date>" trick.

	   This is almost like using the '-D' option, but it looks for
	   revisions extant on <date> only along the given branch.
	   
	   As in #1, you can't commit to this kind of working area,
	   because it has a sticky date referring to revisions in the
	   middle of a branch.


	3. You can branch a branch.

	   If you add a branch tag to file in a working directory that was
	   checked out on a branch, you will branch the branch.  This
	   works just fine, though you'll have to play some games to merge
	   everything back together again.  You'll also create 6-part
	   revision numbers.  (They'll be 8-part revision numbers if you
	   branch a branch that started out with some unmodified files the
	   Vendor branch.  Think about it.  How does revision
	   1.2.4.2.4.2.2.1 grab you?)


+4C.17	Why do I get the latest files on the branch when I tried to
	"update -r <tag>"?

	If "update -r <tag>" always retrieves the latest files on a
	branch, then <tag> is a branch tag.  A branch tag is supposed to
	be used to grab a branch to work on.  Since you can't modify a
	file in the middle of a branch, checking out a <branch_tag> will
	give you the latest revision on the branch.

	If you want to "checkout" a specific collection of revisions, you
	must use a "non-branch" tag.  See the first part of 4C.16.

	You *can* branch off a branch, but it is rarely needed.



----------------
-- Section 4D --	Tricks of the Trade
----------------

This section covers topics ranging from simple ideas that occur to every
CVS user to time-saving procedures I consider difficult to understand.

Some are therefore dangerous.  Avoid anything you don't fully understand.


 **** Questions:

=4D.1	How can you even check in binary files, let alone allow CVS to
	do its auto-merge trick on them?
 4D.2	Can I edit the RCS (",v") files in the Repository?
 4D.3	Can I edit the ./CVS/{Entries,Repository,Tag} files?
=4D.4	Someone executed "admin -o" and removed revisions to which
	tags/symbols were attached.  How do I fix them?
=4D.5	How do I move a magic branch tag?
 4D.6	Can I use RCS locally to record my changes without making them
	globally visible by committing them?
 4D.7	How can I allow access to the Repository by both CVS and RCS?
=4D.8	I "updated" a file my friend "bubba" committed yesterday.
	Why doesn't the file now have a modified date of yesterday?
#4D.9	While in the middle of a large "commit", how do I run other
	commands, like "diff" or "stat" without seeing lock errors?
 4D.10	Why does the merge occasionally resurrect lines of code?
=4D.11	Why does the merge fail when my "rcsmerge" program is
	configured to use GNU diff version 2.1 or later?
 4D.12	What the hell is Entries.Static?
=4D.13	Why did I get the wrong Repository in the loginfo message?
=4D.14	Can I have multiple source repositories, one for each project?
 4D.15	How do I run CVS setuid so I can only allow access through the
	CVS program itself?
 4D.16	How about using groups and setgid() then?
 4D.17	How do I use the "commitinfo" file?
 4D.18	How do I use the "loginfo" files?


 **** Answers:

=4D.1	How can you even check in binary files, let alone allow CVS to
	do its auto-merge trick on them?

	If you configure RCS and CVS to use the GNU version of diff with
	the '-a' option, CVS and RCS will handle binary files.  See
	section 4A for configuration info.

	You also need to apply the '-ko' flag to the files to avoid
	expanding RCS keywords, which can be done via:

		cvs admin -ko filename

	(You should be able to do it by handing "import" the -ko option,
	 but that isn't yet in the official release.)

	The only real problem occurs when "cvs update" attempts to merge
	binary revisions committed elsewhere into a modified working file.
	This can be a particular problem if you are trying to use CVS on
	Frame or Interleaf (document processing systems) that produce
	non-text output.

	[[I know of no solution to this other than to keep binaries in
	some text form as "source" (real binaries could be uuencoded,
	documents could be stored in "exported" (something like SGML)
	form.]]


 4D.2	Can I edit the RCS (",v") files in the Repository?

	Yes, but be very careful.  The RCS files are not free-form files,
	they have a structure that is easily broken by hand-editing.  The
	only time I would suggest doing this is to recover from emergency
	failures that are difficult to deal with using CVS commands,
	including the "admin" command, which can talk directly to RCS.

	Though no one actively encourages the editing of RCS files, many
	people have succumbed to the urge to do so when pressed for time.
	The reasons given, usually with evident contrition, include:

	- Editing mistakes in, or adding text to, log entries.  (If you
	  have RCS 5.6 or later, you should use `cvs admin -m'.)
	- Renaming or moving symbolic names.  (You should `cvs admin -N'
	  instead.)
  	- Unlocking a file by changing the "locker" from someone else to
	  yourself.  (It's safer to use `cvs admin -u -l'.)
	- Making global changes to past history.  Example:  Eradicating
	  former employees names from old documents and Author entries.
	  (And someone thought the "history" command was evidence of Big
	   Brother!  I had never realized how much help CVS/RCS could have
	   provided to The Ministry of Truth.)


 4D.3	Can I edit the ./CVS/{Entries,Repository,Tag} files?

	Yes, but with CVS 1.3 and later, there is almost no reason to edit
	any of the CVS administrative files.

	If you move pieces of your Repository around it can be faster to
	edit all the ./CVS/Repository files rather than checking out a
	large tree.  But that is nearly the only reason to do so.


=4D.4	Someone executed "admin -o" and removed revisions to which
	tags/symbols were attached.  How do I fix them?

	It depends on what you mean by "fix".  I can think of  three ways
	to fix your predicament:


	1. Remove the tags.

	   Assuming you really wanted to get rid of the revision and its
	   associated tags, you can remove them with the "admin" command.
	   The "tag -d" command will only remove tags attached to existing
	   revisions.  You can remove a tag, even if it is attached to a
	   non-existent filename, by typing:

		cvs admin -N<tag> <file>

	2. Retrieve the outdated revision.

	   Using CVS and RCS, there is no way to reconstruct an outdated
	   revision.  You will have to resort to backups.

	3. Move the Tags to another revision in each file.

	   If you want to move the tags to another valid revision, you
	   have two choices, both of which require that you find all the
	   revision numbers of the files you want to "tag" and execute the
	   following command sequences on each <file>.

		a. Use "update" to grab the revision you want, then
		   execute a normal "tag" command to Tag that revision:

			cvs update -r <rev> <file>
			cvs tag <tag> <file>

	   	b. Use "admin" to set the tag to a specific revision:

			cvs admin -N<tag>:<rev> <file>


=4D.5	How do I move a magic branch tag?

	If the <branch_tag> refers to a physical branch within an RCS
	file, renaming a tag will make the existing branch in the file
	seem to disappear.  This is not a good idea.

	If the magic branch has never had a revision committed to it, you
	can move the branch by re-executing the "tag" or "rtag" command
	that created it.  The <branch_tag> will be moved to the place
	where it would have appeared if you were tagging the file for the
	first time.


 4D.6	Can I use RCS locally to record my changes without making them
	globally visible by committing them?

	You can, but it will probably confuse CVS to have ",v" files in
	your working directory.  And you will lose all your log entries
	when you finally commit it.

	Your best bet is to create your own CVS branch and work there.
	You can commit as many revisions as you want, then merge it back
	into the main line when you are finished.


 4D.7	How can I allow access to the Repository by both CVS and RCS?

	The first step is to try not to.  If some people are using CVS,
	there is no reason for everyone not to.  It is not hard to learn
	the basics and CVS makes certain operations *easier* than a series
	of RCS commands.  Personal preference in what software tools can
	be applied to a shared Repository has to take second place to
	system integration needs.  If you disagree, try writing some Lisp
	code for inclusion in your Unix kernel and see what kind of
	reception you get.

	If you really must allow routine RCS access to the CVS Repository,
	you can link an RCS sub-directory into a piece of the Repository:

		ln -s /Repository/some/directory/I/want RCS

	and RCS will work just fine.


	Those who are using RCS will have to keep the following in mind:

	1. If a file was originally added to the Repository by "import"
	   and has not been changed using CVS, the *RCS* default branch
	   will remain attached to the Vendor branch, causing revisions
	   checked-in by "ci" to wind up on the Vendor branch, instead of
	   the main branch.  Only CVS moves the RCS default branch on
	   first commit.

	   The way around this is to checkin (using "ci") all the files
	   first and move them into the Repository.  That way they won't
	   have Vendor branches.  Then RCS will work OK.

	2. It is possible to use "rcs" and "ci" to make the files unusable
	   by CVS.  The same is true of the CVS "admin" command.

	3. Normal RCS practice locks a file on checkout with "co -l".  In
	   such an environment, RCS users should plan to keep survival
	   gear and food for at least 30 days near their desks.  When
	   faced with bizarre and unexpected permission errors, howling
	   mobs of slavering CVS users will run the RCS users out of town
	   with pitchforks and machetes.

	4. Though files checked in by RCS users will correctly cause
	   "up-to-date" failures during CVS "commits" and they will be
	   auto-merged into CVS working directories during "update", the
	   opposite won't happen.

	   RCS users will get no warning and will not be required to merge
	   older work into their code.  They can easily checkin an old
	   file on top of a new revision added by CVS, discarding work.

	   See the howling mob scenario described above.


	RCS is great.  I have used it for years.  But I wouldn't mix it
	this way.  In a two-camp society, you are asking for real trouble,
	both in technical hassles to clean up and in political hassles to
	soothe.


=4D.8	I "updated" a file my friend "bubba" committed yesterday.
	Why doesn't the file now have a modified date of yesterday?

	CVS restores dates from the RCS files only on first "checkout".
	After that, it is more important to maintain a timestamp relative
	to the other files in the working directory.

	Example: I commit a source file at 5PM.  You commit the same file
	at 6PM.  At 7PM, I compile my file.  Then I execute "update".  If
	CVS sets the date to the one in the RCS file, the file would be
	given a timestamp of 6PM and my Makefile wouldn't rebuild anything
	that depended on it.  Bad news.

	Note that the same logic applies to retrieving a revision out of
	the repository to replace a deleted file.  If CVS changes your
	file in an existing working directory, whether it was because a
	new revision was committed by someone else or because you deleted
	your working file, the timestamp on the retrieved working file
	*must* be set to the current time.

	When you first retrieve a file, there is no reason to expect any
	particular timestamp on the file within your working area.  But
	later, when dependency checking is performed during a build, it is
	more important for the timestamps on the local files to be
	consistent with each other than than it is for working files to
	match the timestamps on the files in the Repository.


#4D.9	While in the middle of a large "commit", how do I run other
	commands, like "diff" or "stat" without seeing lock errors?

	Type:
		cvs -n <command>


	The '-n' option to the main cvs command turns off lock checking, a
	reasonable act given the promise offered by '-n' not to alter
	anything.  The "diff", "log" and "stat" commands all provide the
	same information with and without the '-n' option.

	Warning: Ignoring locks can produce inconsistent information
	across a collection of files if you are looking at the revisions
	affected by an active commit.  Be careful when creating "patches"
	from the output of "cvs -n diff".  If you are looking only at your
	working files, tagged revisions, and BASE revisions (revisions
	whose numbers are read from your CVS/Entries files), you should
	get consistent results.  Of course, if you catch a single file in
	the middle of RCS activity, you might get some strange errors.

	Note that this is "cvs -n <command>".  The visually similar
	command "cvs <command> -n" has no relation to the former usage and
	has an entirely different meaning for each command.

	"cvs -n update" also works in the middle of a commit, providing
	slightly different information from a plain "cvs update".  But, of
	course, it also avoids modifying anything.

	You could also use the RCS functions, "rlog" and "rcsdiff" to
	display some of the information by referring directly to the
	Repository files.

	You need RCS version 5 or later for the commands described above
	to work entirely reliably.


 4D.10	Why does the merge occasionally resurrect lines of code?

	The diff3 program provided by GNU diff version 1.15 has a bug
	that occasionally causes text to come back from the dead.

	If you plan to upgrade to the latest GNU diff program, see the
	next question.


=4D.11	Why does the merge fail when my "rcsmerge" program is
	configured to use GNU diff version 2.1 or later?

	A change in the overlap format was introduced in GNU diff3
	between versions 2.0 and 2.1.

	To get consistent rcsmerge behavior, you have four choices:

	1. Go back to using GNU diff 1.15 or 2.0.  If you want to use
	   GNU diff 2.1 or later, you'll have to pick one of the other
	   three choices in this list.

	2. Grab RCS version 5.6.0.1 from an FSF archive and set the
	   DIFF3_A macro to '1' as it tells you to in the Makefile:

		#define DIFF3_A 1

	3. Patch the RCS 5.6 source.  Change line 84 in "merger.c" from:

		DIFF3, "-am", "-L", label[0], "-L", label[1],
	   to
		DIFF3, "-amE", "-L", label[0], "-L", "", "-L", label[1],

	4. Wait both for RCS version 5.7 to be released and for a new
	   version of CVS that can deal with it.


 4D.12	What the hell is Entries.Static?

	Each ./CVS administrative directory contains an Entries file,
	listing the files under CVS in the directory above it.  If a new
	file is added to the Repository, an "update" command copies it
	out of the Repository and adds it to the Entries file.

	If your ./CVS directory has an Entries.Static file in it, CVS
	checks it before bringing new files out of the Repository.  If a
	new file is *not* in Entries.Static, it is not checked out.

	The Entries.Static file is created by checking out something that
	doesn't include all files in a directory.  Without an
	Entries.Static file, the first "update" would bring more files
	out of the Repository.

	Examples:

	- A multi-module checkout renamed with the "checkout -d" option.

	- Checking out a module specified with directory and filenames.

	The Entries.Static file is removed by an "update" with the
	'-A', '-r' or '-D' option.


=4D.13	Why did I get the wrong Repository in the loginfo message?

	You probably:

	      - Use multiple Repositories.

	      - Configured CVS to use absolute pathnames in the
		./CVS/Repository file.

	      - Typed the "commit" command in one Repository with your
		$CVSROOT pointing at the other.


	"commit" and all other CVS commands will heed an absolute pathname
	in the ./CVS/Repository file (or in the "-d CVSrootdir" override),
	but the log function doesn't take arguments -- it just looks at
	$CVSROOT.


=4D.14	Can I have multiple source repositories, one for each project?

	Yes, you can have as many Repositories as you like.  But each
	Repository must be managed separately, creating additional work.

	Question 4A.1 provides a short description of setting up a
	single Repository.  A few additional considerations:

	1. It is a good idea to start by creating a single Repository and
	   split it up (or create additional Repositories) only if you
	   believe it is really necessary.  I would only create a new
	   Repository if the data is completely disconnected from the rest
	   of the main Repository.

	2. If there is a lot of overlap among the developers working on
	   the collections of files you want to place in different
	   Repositories, or if there is any connection between those
	   collections, I would go out of my way to create a single
	   Repository.  It is much easier to manage.
	   
	3. Disk space should not be a factor since you can build up a
	   Repository using symbolic links and/or remote mounts.

	4. Each Repository is completely distinct.  You can't check out
	   modules from different Repositories at the same time.  A better
	   way of looking at it is that if you *can* check out two modules
	   or directories with a single "checkout" command (without
	   contortions or explicit absolute pathnames), then they are in
	   the same Repository.

	5. To "checkout" modules from multiple Repositories, you must use
	   the "cvs -d" option on all CVS commands or alter your $CVSROOT
	   variable when you change focus to another Repository.  If you
	   work with multiple Repositories, it is a good idea to configure
	   CVS to use absolute pathnames in the ./CVS/Repository file,
	   since most commands (other than "checkout") will use that file
	   rather than $CVSROOT.

	6. If you configure CVS to use relative pathnames in your
	   ./CVS/Repository files, you must always be careful to set your
	   $CVSROOT properly or you will get unexpected results.

	   One monster of an unexpected result can happen when you have
	   two modules or directories by the same name at the same
	   relative path inside the Repository, in two different
	   Repositories.  You can update a directory with completely
	   unrelated files.  This is not a fanciful example -- a
	   Repository is occasionally duplicated for release purposes in
	   which case *all* the paths in the two Repositories are the
	   same.


 4D.15	How do I run CVS setuid so I can only allow access through the
	CVS program itself?

	Setuid to root is not a great idea.  Any program that modifies
	files and is used by a widely distributed group of users is not a
	good candidate for a setuid program.  (The worst suggestion I've
	ever heard was to make *Emacs* setuid to root.)

	Root access on Unix is too powerful.  Also, it might not work in
	some (secure?) environments.

	Running it setuid to some user other than root might work, if you
	add this line to main.c near the beginning:

		setuid(geteuid());

	Otherwise it uses *your* access rights, rather than the effective
	uid's.

	Also, you have to invent a fake user whose name will show up in
	various places.  But many sites, especially those who might want a
	setuid CVS for "security", want personal accountability -- no
	generic accounts.  I don't know whether accountability outweighs
	file security.

	And finally, unless you take action to limit the "admin"
	command, you are leaving yourself unprotected anyway.


 4D.16	How about using groups and setgid() then?

	Here is a way to run CVS setgid in some environments:

	0. Stick this near the front of the main() in main.c:

		setgid(getegid());

	   This will allow "access" to work on systems where it
	   only works on the real gid.

	1. Create a group named "cvsg", for example.  Name it as you wish.

	2. Put *no* users in the "cvsg" group.  You can put Repository
	   administrators in this group, if you really want to.

	3. Set the cvs executable to setgid (not setuid):

		cd /usr/local/bin; chown root.cvsg cvs; chmod 2755 cvs

	4. Make sure every file in the Repository is in group "cvsg":

		chown -R root.cvsg $CVSROOT

	5. Change all directory permissions to 770.  This allows all
	   access to the files by the "cvsg" group (which has no members!)
	   and no access at all to anyone else.

		 find $CVSROOT -type d -exec chmod 2770 {} \;

	This should allow only the cvs program (or other setgid to group
	cvsg) programs to write into the area, but no one else.  Yes the
	user winds up owning the file, but s/he can't find it again later
	since s/he can't traverse the tree.  (If you allow the world
	execute bit (octal 001) on directories, the user who last wrote
	the file can still write to it.)

	If you want to allow read access, check out an entire tree
	somewhere.  You have to do this anyway to build it.

	Note: If you are using a stupid file system that can't inherit
	file groups from the parent directory (even with the "setgid"
	(Octal 2000) bit set), you might have to modify CVS (or RCS) to
	reset the group every time you create a new file.  I have not
	tested this.

	The setgid() method shares the "admin" problem with the
	setuid() method.


 4D.17	How do I use the "commitinfo" file?

	Go read 4B.2 first.

	The "commitinfo" file allows you to execute "sanity check"
	functions before allowing a commit.  If the function exits with a
	non-zero status, the commit is denied.

	To fill out a "commitinfo" file, ask yourself (and those sharing
	your Repository) these questions:

	- Is there anything you want to check or change before someone is
	  allowed to commit a file?  If not, forget commitinfo.

	- Do you want to execute the same exact thing before committing to
	  every file in the Repository?  (This is useful if you want to
	  program the restrictions yourself.)  If so, set up a single line
	  in the commitinfo:

		DEFAULT		/absolute/path/to/program

	  CVS executes the program once for each directory that "commit"
	  traverses, passing as arguments the directory and the files to
	  be committed within that directory.

	  Write your program accordingly.

	- Do you want a different kind of sanity check performed for
	  different directories?  If so, you'll have to decide what to do
	  for all directories and enter lines like this:

		regexp1		/absolute/path/to/program-for-regexp1
		regexp2		/absolute/path/to/program-for-regexp2
		DEFAULT		/absolute/path/to/program-for-all-else


	- Is there anything you want to happen before *all* commits, in
	  addition to other pattern matches?  If so, include a line like
	  this:

		ALL		/absolute/path/to/program

	  It is executed independently of all the above.  And it's
	  repeatable as many times as you like.


 4D.18	How do I use the "loginfo" files?

	See 4B.2 and the "commitinfo" question above.

	The "loginfo" file has the same format as the "commitinfo"
	file, but its function is different.  Where the "commitinfo"
	information is used before a commit, the "loginfo" file is used
	after a commit.

	All the commands in the "loginfo" file should read data from
	standard input, then either append it to a file or send a message
	to a mailing list.  If you want to make it simple, you can put
	shell (the shell used by "popen") command lines directly in the
	"loginfo" (or "commitinfo") file.  These seem to work:

	    ^special  /usr/ucb/Mail -s %s special-mailing-list
	    ^other    /usr/ucb/Mail -s %s other-mailing-list
	    DEFAULT   (echo '===='; echo %s; cat) > /path/name/to/log/file



----------------
-- Section 4E --	Weirdness
----------------

 **** Questions:

 4E.1	Explain: "ci error: unexpected EOF in diff output"
=4E.2	Explain: "RCS file /Repository/module/file.c,v is in use"
=4E.3	I don't want a Vendor branch.  Why can't I work on the main trunk?
 4E.4	Merges can't work.  I don't trust them.  If you won't change it to
	something I can understand, I won't use CVS.
 4E.5	Explain: "co error, line 2: Missing access list"
+4E.6	Explain: "error: RCS file name `xyz .c' contains white space"
+4E.7	Explain: cvs checkout: warning: <X> is not (any longer) pertinent


 **** Answers:

 4E.1	Explain: "ci error: unexpected EOF in diff output"

	RCS versions earlier than 5.5 print the above error when a file
	does not end in a newline character.  It can be caused by:

	  - Editing with Emacs and not using "require-final-newline".
	  - Committing a binary file.
	  - Filesystem failures (NFS!) that put nulls in your file.

	The solution is to upgrade to RCS 5.5 or later.  (Of course, this
	won't fix filesystem failures.  It will merely allow RCS (and
	therefore CVS) to handle the file without error.)


=4E.2	Explain: "RCS file /Repository/module/file.c,v is in use"

	This is an RCS error that occurs when its internal lock file has
	been left around by an RCS command interrupted by some sort of
	system crash, disk failure or SIGKILL signal.

	Go into the Repository and look for files with names similar to
	"file.c,v", usually starting with ',', '_' or '#'.  Make
	sure they are really crash remnants and do not belong to
	transactions in progress -- a recent last-modified timestamp
	is a good indicator of a live transaction.  Delete them.


=4E.3	I don't want a Vendor branch.  Why can't I work on the main trunk?

	The Vendor branch is the way "import" deals with a Vendor
	release.  If you do it any other way, you are wasting your time.
	CVS was designed to work this way.

	If you are not working with 3rd party (i.e. Vendor) sources, you
	can skip the "import" and either move pre-existing RCS files into
	the Repository, or apply the RCS "ci" command to your source files
	by hand (creating ",v" files) and move them into the Repository.


 4E.4	Merges can't work.  I don't trust them.  If you won't change it to
	something I can understand, I won't use CVS.

	Some developers have the feeling that three-way merging doesn't
	work.   They don't trust the way the "update" command
	automatically merges committed changes from the Repository into
	the working file.

	Experience has shown that most merges are utterly painless and
	most of the rest are easily resolved.  The few conflicts that
	cause headaches are nearly all due to poor communication between
	developers, a problem no source control system can obliterate.

	Some developers were troubled in the past by flaky Unix software.
	I can't say that everything is perfect, but the tools CVS depends
	on (RCS and diff, mainly) are fairly solid nowadays.  They work.

	Since it does seem to work for most of us, the algorithm is
	unlikely to change soon.  Why not test it on a couple trouble
	spots and if it works for you, use it for a while?  Then you can
	make an informed decision.


 4E.5	Explain: "co error, line 2: Missing access list"

	This is an error message from RCS Version 3 when it tries to read
	a file created by a later version of RCS.

	You should upgrade to the latest version of RCS, which is Version
	5.6.0.1 as I write this.


+4E.6	Explain: "error: RCS file name `xyz .c' contains white space"

	RCS 5.6 doesn't allow white space in filenames.  Apparently this
	restriction will be removed in RCS 5.7, but CVS may still require
	that filenames have no white space in them.


+4E.7	Explain: cvs checkout: warning: <X> is not (any longer) pertinent

	This message occurs in two instances:

	1. When there is an entry in the ./CVS/Entries for file <X> and
	   there is no RCS file in the Repository to back it up.

	   If the working file exists, and hasn't changed (determined from
	   the timestamp) it is removed.


	2. When you try to check out a piece of the Repository with:

		cvs checkout some/place/in/repository/tree

	   and at least the first element of the path (i.e. "some" in the
	   above) exists, but some part of the rest of it does not.

	   The checkout command checks the modules file first for the
	   whole path, then for a prefix of the path as a module name.  If
	   it doesn't find *any* portion of your path in the modules file,
	   it says:

		cvs checkout: cannot find module `<module/path>' - ignored

	   If it finds some set of prefix directories, it prints the
	   message you see.

	   In practice this is usually a spelling error.

	3. If the Repository files you are trying to check out or update
	   are not readable by you, the same problems can occur.
	   Check the permissions on the files involved.


----------------
-- Section 4F --	Related Software
----------------

 **** Questions:

+4F.1	How do I use CVS under Emacs?  Is there an Emacs cvs-mode?
+4F.2	What is GIC (Graphical Interface to CVS)?
+4F.3	What is CAVEMAN?


 **** Answers:

This section covers a small handful of subsystems that connect to CVS in
some way.  Most are "front ends" in that they offer a different user
interface to CVS, but use CVS to perform the normal tasks.

 NOTE:  The short summaries below combine details culled from public
	announcements of the listed software with the personal opinions of
	the author of the FAQ entry.


+4F.1	How do I use CVS under Emacs?  Is there an Emacs cvs-mode?

	The pcl-cvs package distributed with CVS 1.3 is an emacs package
	that helps with the update/commit process.  When you are ready to
	update, you use the 'cvs-update' command within emacs.  This
	executes "update" and fills a cvs-mode buffer with a line for each
	file that changed.  The most helpful features are: descriptive
	words for what happened (i.e. Merged or Conflict rather than 'U'),
	single keys bound to diffs and commits, and the ability to mark
	arbitrary groups of files, possibly from different directories,
	for commit as a whole.

	All the developers in my group that use emacs find pcl-cvs a much
	friendlier and more helpful way to update/commit than raw cvs.
	One vi user even converted to emacs just to use pcl-cvs.

				Contributed by Jeffrey M Loomis

+4F.2	What is GIC (Graphical Interface to CVS)?

	GIC is a window interface to CVS written in Tcl/Tk, which attempts
	to hide the normal CVS command line options from novice users.

	GIC works only in a single directory at a time, but it offers most
	of the CVS commands you would normally use.

	GIC can be obtained by anonymous ftp to 

		ftp.cpsc.ucalgary.ca:/pub/marwood/gic-1.0b5.tar.Z

	contact
		David Marwood
		marwood@cpsc.ucalgary.ca

	[[Does someone want to try to describe this better?]]


+4F.3	What is CAVEMAN?

	CAVEMAN is a front end to CVS written in PERL providing a
	collection of features desired by the site where it was developed.

	- The ability to spread a "project" over multiple Repositories.
	- Optional automatic tagging after each commit.
	- Additional locking of files.
	- Extra before and after program hooks.
	- A layer of event logging.
	- All sorts of error messages.
	- Many changes to the semantics of commands.

	It is available via anonymous ftp on llnl.gov [128.115.18.253] as
	gnu/caveman_vX.Y.Z.tar.gz  (The numbers X, Y, & Z vary with time.)

	contact 
	Kathleen Dyer		kdyer@llnl.gov 
				(510)423-6803
				(510)423-5112 FAX


	[[Does someone want to try to describe this better?]]



----------------
-- Section 4G --	Other Systems
----------------

 **** Questions:

 4G.1	I use a NeXT.  Is there anything I need to know?
 4G.2	I use OS/2.  Is there anything I need to know?
 4G.3	I use SCO Unix.  Is there anything I need to know?
 4G.4	I use AIX.  Is there anything I need to know?
=4G.5	I use IRIX.  Is there anything I need to know?
=4G.6	I use an HP system.  Is there anything I need to know?


 **** Answers:

Out of the box, CVS works on most varieties of Unix.  Some near-Unix
systems have a few problems and non-Unix systems have a *lot* of problems.

 4G.1	I use a NeXT.  Is there anything I need to know?

	Under NeXTSTEP 2.2, the tmpnam() function always returns the
	same filename, which breaks "cvs patch".  Apparently the
	"mktemp()" function works OK, but you'll have to hack it up to
	build something that acts like "tmpnam()".

	NeXTSTEP 3.0's Interface Builder uses "nib" directories,
	rather than files in previous revisions.  It removes files it
	doesn't recognize, making it impossible to place such a
	directory under CVS -- the CVS admin directory will be removed.

	[[Anything else?]]


 4G.2	I use OS/2.  Is there anything I need to know?

	[[Well?]]


 4G.3	I use SCO Unix.  Is there anything I need to know?

	[[Well?]]


 4G.4	I use AIX.  Is there anything I need to know?

	[[Well?]]


=4G.5	I use IRIX.  Is there anything I need to know?

	If you see "uid" numbers where you would expect user names, try
	adding -lsun to the link line.  Without it CVS is unable to
	retrieve "passwd" data through NIS.


=4G.6	I use an HP system.  Is there anything I need to know?

	HP distributes RCS version 3 (a circa 1983 release!) with HP-UX.
	CVS does not work with RCS version 3; it requires RCS version 4
	or later.  Your best bet is to find the latest version of RCS
	and install it somewhere.

	HP-UX 8.07 has a serious bug with the mmap system call and NFS
	files; the bug can crash the operating system.  Make sure that
	you configure RCS to avoid mmap by setting has_mmap to 0 in
	RCS's conf.h.  This bug is fixed in HP-UX 9.

				Contributed by Paul Eggert

	If using the setgid() trick described in 4D.16, you will have to
	create an entry in the /etc/privgroup file to give the group
	assigned to the cvs executable setgid permission (see
	setprivgrp(1m)).  Additionally, if you are restricting "read"
	access to the Repository by limiting access to the executable
	(this requires yet another group), then you will require that
	/etc/logingroup exists and is configured correctly (usually it's
	just alink to /etc/group).

				Contributed by Dale Woolridge


=============================================
==  Section 5	====	Past & Future	 ====
=============================================

----------------
-- Section 5A --	Contributors
----------------

 **** Questions:

 5A.1	Who wrote CVS?
=5A.2	You didn't write all of this FAQ, did you?


 **** Answers:


 5A.1	Who wrote CVS?

	Brian Berliner <berliner@sun.com> converted a collection of
	scripts written by Dick Grune <dick@cs.vu.nl> into a C program,
	then added all sorts of features.  He continues to maintain CVS.

	Jeff Polk <polk@bsdi.com> wrote much of the code added between
	revisions 1.2 and 1.3.  Many others were involved at some level.

	Take a look at the README and the ChangeLog files in the CVS
	sources for more details.


=5A.2	You didn't write all of this FAQ, did you?

	In the original hunt for questions to answer (performed in
	Jan/Feb, 1993), I polled hundreds of people and I rephrased all
	sorts of text found on the net.  Because there are so many posers
	of questions, I will list only those who contribute answers or
	help significantly with the content and structure of this
	document.

	Unless a name is included in the answer itself, I didn't use
	anyone else's answers verbatim.  On the other hand, I did use
	ideas and information provided by many.  The people whose email
	postings have added to this document or who have added to my
	understanding are:

	Brian Berliner <berliner@sun.com>, CVS maintainer.
	Paul Eggert <eggert@twinsun.com>, RCS maintainer.

	Gray Watson <gray@antaire.com>
	Per Cederqvist <ceder@signum.se>
	Pete Clark <pclark@is.com>

	    all of whom have sent me copies of their tutorials
	    and local CVS documentation.

	Additional contributors, who have sent me ideas, text, corrections
	and support include (in alphabetical order):

	Donald Amby		<amby@mixcom.mixcom.com>
	Tom Cunningham		<tomc@bouwsma,sps.mot.com>
	Don Dwiggins		<dwig@markv.com>
	Dan Franklin		<dan@diamond.bbn.com>
	Jeffrey M Loomis	<jml@world.std.com>
	Barry Margolin		<barmar@think.com>
	Mark K. Mellis		<mkm@ncd.com>
	Chris Moore		<Chris.Moore@src.bae.co.uk>
	Gary Oberbrunner	<garyo@think.com>
	Steve Turner		<stevet@carrier.sps.mot.com>
	Dave Wolfe		<dwolfe@pffft.sps.mot.com>
	Dale Woolridge		<dwoolridge@cid.aes.doe.ca>

	Plus a myriad Thinking Machines people who posed hundreds of
	questions.


	Please send corrections.  If I forgot you, remind me and I'll add
	your name to the list.


----------------
-- Section 5B --	Bugs and Patches
----------------

This section addresses some known bugs and patches for them.
Large patches will be stored in the FTP area.
See the Development section later for stuff being worked on.

 **** Questions:

 5B.1	Why can't CVS handle deletion of directories?
=5B.2	Why can't CVS handle the moving of sources from one place in the
	directory hierarchy to another?
=5B.3	Why does "checkout" recurse indefinitely if an alias contains
	its own name?
 5B.4	When I typed "cvs update -D <date>", why did it check out all
	sorts of ancient files from the Attic?  Shouldn't it just create
	the set of files and revisions that existed at that date?
 5B.5	When I typed "cvs update -D <date>" in my branch, why did it
	screw up all my files?
 5B.6	When I executed "checkout" into an existing directory I got "No
	such file or directory" errors.  Why?
 5B.7	Why does "update" send all output to the terminal after 26 files
	have been updated?
+5B.8	Why doesn't the "-I !" option work in update and import?


 **** Answers:

 5B.1	Why can't CVS handle deletion of directories?

	An oversight, probably.  [[Fixed in a future release?]]


=5B.2	Why can't CVS handle the moving of sources from one place in the
	directory hierarchy to another?

	A "renaming database" has been proposed to track the history of
	pathname changes in the Repository.  A general solution is a
	difficult problem.  See 4B.9 and 2C.4.


=5B.3	Why does "checkout" recurse indefinitely if an alias contains
	its own name?

	A bug in the handling of aliases.  [[I'll remove this one when
	the bug is fixed.]]


 5B.4	When I typed "cvs update -D <date>", why did it check out all
	sorts of ancient files from the Attic?  Shouldn't it just create
	the set of files and revisions that existed at that date?

	This seems to be a bug, but is really the lack of any obvious
	place to store the date when a file is "removed".

	There are four ranges of dates that CVS has to deal with when
	trying to determine what revision was available on <date>:

	1. Dates before the earliest revision in the file.

	2. Dates between any two revisions in the file.

	3. Dates between the latest revision in the file and the date
	   when the file was moved to the Attic by "commit".

	4. Dates after moving the file to the Attic.

	Since the date when a file is moved to the Attic is not stored
	anywhere, CVS can't tell the difference between #3 and #4.
	To avoid not producing a file that should exist in case #3, it
	produces extraneous files in case #4.


	For the above reason, if you have removed files in the Attic, it
	is better to use "-r <tag>, or even "-r HEAD" than to use a
	date spec.


 5B.5	When I typed "cvs update -D <date>" in my branch, why did it
	screw up all my files?

	Currently, the internal routine ("version_ts") that looks up
	info about a file,  overrides both the tag and date if *either*
	the tag or date is specified on the command line.  If only the
	date is specified, it should not override a branch tag, but it
	does.


 5B.6	When I executed "checkout" into an existing directory I got "No
	such file or directory" errors.  Why?

	Though the man page says that "checkout" turns into an
	"update -d" in directories that already exist, it is referring
	to directories that already exist *and* were created by CVS.

	When you try to run "checkout" on top of an existing directory
	structure, some of which wasn't created by CVS, it will handle
	directories and non-CVS files within directories already under
	CVS, but it will display the above error on non-CVS files within
	non-CVS directories.


 5B.7	Why does "update" send all output to the terminal after 26 files
	have been updated?

	CVS uses the "tmpnam()" function to generate temporary file names.
	The ANSI standard for the "tmpnam()" function says:

	"The tmpnam function generates a different string each time it is
	called, up to TMP_MAX times.  If it is called more than TMP_MAX
	times, the behavior is implementation defined."

	Later it says that the value of "TMP_MAX shall be at least 25."

	On some platforms, the above specification is taken literally by
	turning "at least 25" into "exactly 26" and by doing something
	foolish (i.e. "implementation defined") after that.  Some
	systems return the same name repeatedly, which causes one form of
	trouble.  Others return NULL or garbage, which causes a different
	form of trouble.

	The broken systems appear to be cycling a single character through
	the alphabet.  SunOS cycles 3 characters through the alphabet, so
	it won't cause trouble until 26 cubed or 17576 calls to
	"tmpnam()".

	Since CVS doesn't depend on the exact format of the tmp files, the
	workaround is to provide a "tmpnam()" that doesn't have a limit
	on the number of calls to it.

+5B.8	Why doesn't the "-I !" option work in update and import?

	A bug.  See the patch named "unoff/import_ignore" in the CVS FTP
	archive


 [[Section 5B needs more, but should probably wait until the
   patch release comes out.  Then we can document them for real and
   provide pointers to patches in the FTP area.]]


----------------
-- Section 5C --	Development
----------------

   I hope to record three types of information here:

	1. Plans (with the developer's name attached) for fixing larger
	   bugs.  (Smaller bugs should just show up, with a patch or a
	   reference to a patch stored in the FTP archive, in the
	   "Bugs" section above.)

	2. Plans for new development, with the developer's name attached.
	   (If the developer is particularly gonzo, it might also show a
	    completion date.)

	3. Requests for ideas and code to fix unresolved issues.


 **** Questions:

=5C.1	Where do I send bug reports?
=5C.2	Where do I send fixes and patches?
 5C.3	Where do I send ideas for future development?
 5C.4	What plans are there for fixing bugs?
=5C.5	What plans are there for new features?
=5C.6	I have some time and I'd like to help.  What can I do for you?


 **** Answers:

=5C.1	Where do I send bug reports?

	First make sure it is a bug.  Talk to your friends, coworkers and
	anyone you know who uses CVS.  Search this FAQ for related issues.
	Then test it carefully.  Try out variations to narrow down the
	problem.  Make sure it is repeatable.  Look for workarounds so you
	can report them.

	If you are still sure it's a bug and you tried to fix it, skip to
	the next question.  Otherwise, send a message to the info-cvs
	mailing list containing one of the following:

	1. If you have a good repeatable case and you think you know what
	   is going on, then describe the problem in detail.  Include
	   a workaround if you have one.

	2. If you have no idea what is going on, go ahead and send a
	   question to the info-cvs mailing list.  Include any information
	   you have describing the symptoms.

	If careful testing reveals an RCS bug rather than a CVS bug, you
	can sendbug reports to: rcs-bugs@cs.purdue.edu


=5C.2	Where do I send fixes and patches?

	First make sure the "fix" does something useful.  Have someone to
	review your fix.  It is better to spend a bit of one person's
	thinking time than to waste the time of thousands of people trying
	to understand your fix.

	If you tried to fix it and the patch is small, include the patch
	in your message.  Make sure the patch is based on the latest
	released version of CVS.

	If you tried to fix it and the patch is large, you should think
	about why it is so large.  Did you add a generally useful feature,
	or did it grow out of hand?

	If you still believe it is solid, send it to the maintainer of the
	FTP archive (currently the author of this FAQ) for inclusion in
	the CVS FTP archive and to Brian Berliner, the maintainer of CVS.


 5C.3	Where do I send ideas for future development?

	[[Brian?]]


 5C.4	What plans are there for fixing bugs?

	David G. Grubbs <dgg@think.com> plans/hopes to:

	      - Fix the release command to be more sophisticated about
		foreign directories, renaming and to allow the release of
		anything in the working directory.

	      - Fix the history command to track changes made in the
		underlying layers since I originally wrote it, including
		making "tag" work with history.



	[[Brian?]]
	[[Others?]]


=5C.5	What plans are there for new features?

	David G. Grubbs <dgg@think.com> plans/hopes to:

	      - Implement the design described in the Branching spec
		distributed to this list in January, 93.  It attempts to
		address the problem of merging between arbitrary branches
		and to fully support the idea of "branching".

	      - Add a feature to "cvs add" (Maybe a '-a' switch.) to
		add a file by the same name as one in the Attic, by
		dragging it back out of the Attic.  (This connects to the
		branching code, since a way has to be added to drag a
		file out of the Attic that is merged onto the Main branch
		from being only on a side-branch.)

	      - If no one else wants to deal with it, I would like to
		enhance the whole "modules" concept to cover more of
		the naming problem and to allow more complicated access
		control.  (Optional, of course.)

	      - Create a set of configuration files (in addition to or to
		supersede the cvsignore files) to allow the setting of
		a wide variety of site-specific options.


	Brian Berliner <berliner@sun.com> plans/hopes to:

	      - [[Rename database?]]

		[[Brian?  Any plans?]]


	Paul F. Kunz <pfkeb@slac.stanford.edu> has produced a version of
		CVS (RCVS) that runs remotely.

		On the host "ftp.slac.stanford.edu", you can find:
		  Sources:	pub/sources/rcvs-0.5.0.tar.Z
		  Paper:	pub/preprints/slac-pub-5923.ps


	[[Others?]]


=5C.6	I have some time and I'd like to help.  What can I do for you?

	You can review this document, correct errors and fill in any of
	the incomplete sections.

	You can add to the contrib area, which contains useful ways to use
	some of the programmable CVS facilities (loginfo, commitinfo) or
	ways of connecting to work environments (pcl-cvs).

	You could write a regression test suite.  Or at least a scaffold
	into which we can drop tests.

	You can write specs for new features, fix bugs, review the man
	page or . . .

	[[Brian?]]

	[[Is there some way we can register someone as working
	  on something or should we just stay in the "implement it and
	  send it to me" mode?]]


=================================================
==  Section 6	====	Table of Contents    ====
=================================================

===========================================================================
== Frequently Asked Questions about CVS (The Concurrent Versions System) ==
===========================================================================

============================================
==  Section 0	====	Introduction	====
============================================

Questions are divided into five numbered Sections.  Sections are divided
into lettered sub-sections.  The questions are numbered sequentially
within each sub-section, though they are in no particular order.

	1. What is CVS?
	   A. What is CVS?  What's it for?  Why CVS?
	   B. Where do I find it?  Where can I find Help?
	   C. How does CVS differ from other similar software?
	   D. What do you mean by .  .  .? (Definitions)

	2. User Tasks
	   A. Getting Started
	   B. Common User Tasks
	   C. Less Common User Tasks
	   D. General Questions

	3. Commands
	   A. through P.  One section for each CVS command.

	4. Advanced Topics
	   A. Installing CVS
	   B. Setting up and Managing the Repository
	   C. Branching
	   D. Tricks of the Trade
	   E. Weirdness
	   F. Related Software
	   G. Other Systems

	5. Past & Future
	   A. Contributors.
	   B. Bugs and Patches
	   C. Development

	6. Table of Contents



============================================
==  Section 1	====	What is CVS?	====
============================================

----------------
-- Section 1A --	What is CVS?  What's it for?  Why CVS?
----------------
 1A.1	What does CVS stand for?  Can you describe it in one sentence?
 1A.2	What is CVS for?  What does it do for me?
 1A.3	How does CVS work?
=1A.4	What is CVS useful for?
=1A.5	What is CVS *not* useful for?
=1A.6	Why isn't it called OSCO (Online Source COntrol)?

----------------
-- Section 1B --	Where do I find CVS?  Where can I find Help?
----------------
 1B.1	How do I get more information about CVS?
 1B.2	Is there an archive of CVS material?
 1B.3	How do I get a copy of the latest version of CVS?
 1B.4	Is there any other documentation?  How about tutorials?
 1B.5	Is there a mailing list devoted to CVS?  How do I get on it?
 1B.6	What prayers are appropriate for each of the major denominations
	(e.g. 20's, 50's, 100's) when issuing complex CVS commands?
+1B.7	How do I get files out of the archive if I don't have FTP?

----------------
-- Section 1C --	How does CVS differ from other similar software?
----------------
=1C.1	How does CVS differ from RCS?
 1C.2	How does CVS differ from SCCS?
=1C.3	How does CVS differ from ClearCase?
 1C.4	How does CVS differ from TeamWare?
 1C.5	How does CVS differ from SunPro?
 1C.6	How does CVS differ from Aegis?
 1C.7	How does CVS differ from Shapetools?
+1C.8	How does CVS differ from TeamNet?
+1C.9	How does CVS differ from ProFrame?
+1C.10	How does CVS differ from CaseWare/CM?
+1C.11	How does CVS differ from Sublime?

----------------
-- Section 1D --	What do you mean by . . .? (Definitions)
----------------
#1D.1	What are "The Repository", "$CVSROOT" and "CVSROOT"?
 1D.2	What is an RCS file?
 1D.3	What is a working file?
 1D.4	What is a working directory (or working area)?
 1D.5	What is "checking out"?
=1D.6	What is a revision?
 1D.7	What is a "Tag"?
=1D.8	What are "HEAD" and "BASE"?
=1D.9	What is a Branch?
=1D.10	What is "the trunk"?
=1D.11	What is a module?
+1D.12	What does "merge" mean?


==========================================
==  Section 2	====	User Tasks    ====
==========================================

----------------
-- Section 2A --	Getting Started
----------------
 2A.1	What is the first thing I have to know?
 2A.2	Where do I work?
=2A.3	What does CVS use from my environment?
 2A.4	OK, I've been told that CVS is set up, my module is named
	"ralph" and I have to start editing.  What do I type?
 2A.5	I have been using RCS for a while.  Can I convert to CVS without
	losing my revision history?  How about converting from SCCS?

----------------
-- Section 2B --	Common User Tasks
----------------
#2B.1	What is the absolute minimum I have to do to edit a file?
=2B.2	If I edit multiple files, must I type "commit" for each one?
 2B.3	How do I get rid of the directory that "checkout" created?
=2B.4	How do I find out what has changed?
=2B.5	I just created a new file.  How do I add it to the Repository?
=2B.6	How do I merge changes made by others into my working directory?
 2B.7	How do I label a set of revisions so I can retrieve them later?
 2B.8	How do I checkout an old release of a module, directory or file?
 2B.9	What do I have to remember to do periodically?

----------------
-- Section 2C --	Less Common User Tasks
----------------
 2C.1	Can I create sub-directories in my working directory?
 2C.2	How do I add new sub-directories to the Repository?
 2C.3	How do I remove a file I don't need?
=2C.4	How do I rename a file?
 2C.5	How do I make sure that all the files and directories in my
	working directory are really in the Repository?
=2C.6	How do I create a branch?
=2C.7	How do I modify the modules file?  How about the other files in
	the CVSROOT administrative area?
+2C.8	How do I split a file into pieces, retaining revision histories?

----------------
-- Section 2D --	General Questions
----------------
=2D.1	How do I see what CVS is trying to do?
 2D.2	If I work with multiple modules, should I check them all out and
	commit them occasionally?  Is it OK to leave modules checked out?
 2D.3	What is a "sticky" tag? What makes it sticky? How do I loosen it?
 2D.4	How do I get an old revision without updating the "sticky tag"?
=2D.5	What operations disregard sticky tags?
=2D.6	Is there a way to avoid reverting my Emacs buffer after
	committing a file?  Is there a "cvs-mode" for Emacs?
 2D.7	How does conflict resolution work?  What *really* happens if two
	of us change the same file?
 2D.8	How can I tell who has a module checked out?
#2D.9	Where did the .#<file>.1.3 file in my working directory come from?
 2D.10	What is this "ignore" stuff?
 2D.11	Why does .cvsignore not ignore directories?
 2D.12	Is it safe to interrupt CVS using Control-C?
 2D.13	How do I turn off the "admin" command?
 2D.14	How do I turn off the ability to disable history via "cvs -l"?
 2D.15	How do I keep certain people from accessing certain directories?


========================================
==  Section 3	====	Commands    ====
========================================

----------------
-- Section 3A --	"add", "ad", "new"
----------------
 3A.1	What is "add" for?
 3A.2	How do I add a new file to the branch I'm working on?
 3A.3	Why did my newly added file end up in the Attic?
 3A.4	How do I put a new file on the Main Branch and branch off from
	there onto my default branch?

----------------
-- Section 3B --	"admin", "adm", "rcs"
----------------
 3B.1	What is "admin" for?
 3B.2	Wow!  Isn't that dangerous?
=3B.3	What would I normally use "admin" for?
=3B.4	What should I avoid when using "admin"?
-3B.5	How do I restrict the "admin" command?  The -i flag in the modules
	file can restrict commits.  What's the equivalent for "admin"?
+3B.6	I backed out a revision with "admin -o" and committed a
	replacement.  Why doesn't "update" retrieve the new revision?

----------------
-- Section 3C --	"checkout", "co", "get"
----------------
 3C.1	What is "checkout" for?
 3C.2	What is the "module" that "checkout" takes on the command line?
 3C.3	Isn't a CVS "checkout" just a bunch of RCS checkouts?
 3C.4	What's the difference between "update" and "checkout"?
 3C.5	Why can't I check out a file from within my working directory?
 3C.6	How do I avoid dealing with those long relative pathnames?
 3C.7	Can I move a checked-out directory?  Does CVS remember where it
	was checked out?
#3C.8	How can I lock files on checkout the way RCS does?
+3C.9	What is "checkout -s"?  How is it different from "checkout -c"?

----------------
-- Section 3D --	"commit", "ci", "com"
----------------
 3D.1	What is "commit" for?
=3D.2	If I edit ten files, do I have to type "commit" ten times?
 3D.3	Explain: cvs commit: Up-to-date check failed for `<file>'
 3D.4	What happens if two people try to "commit" conflicting changes?
 3D.5	I committed something and I don't like it.  How do I remove it?
=3D.6	Explain: cvs commit: sticky tag `V3' for file `X' is not a branch
=3D.7	Why does "commit -r <branch_tag>" put new files in the attic?
+3D.8	Why does "commit -r <rev>" ignore <rev> on an added file?

----------------
-- Section 3E --	"diff", "di", "dif"
----------------
 3E.1	What is "diff" for?
=3E.2	Why did "diff" display nothing when I know there are later
	committed revisions in the Repository?
#3E.3	How do I display what changed in the Repository since I last
	executed "checkout", "update" or "commit"?
=3E.4	How do I display the difference between my working file and what
	I checked in last Thursday?
=3E.5	Why can't I pass the --unified option to "diff"?

----------------
-- Section 3F --	"export", "exp", "ex"
----------------
 3F.1	What is "export" for?
=3F.2	Why does it remove the RCS keywords so I can't use the "ident"
	command on the source files?
=3F.3	Can I override the '-kv' flag CVS passes to RCS?
=3F.4	Why the hell not?
 3F.5	Why does "export -D" check out every file in the Attic?

----------------
-- Section 3G --	"history", "hi", "his"
----------------
 3G.1	What is "history" for?
 3G.2	Of what use is it?
 3G.3	What is this, Big Brother?
 3G.4	I deleted my working directory and "history" still says I have
	it checked out.  How do I fix it?
 3G.5	So I *can* edit the History file?
 3G.6	Why does the history file grow so quickly?
 3G.7	What is the difference between "cvs history -r <tag/rev>" and
	"cvs history -t <tag>"?
 3G.8	Why does "cvs history -c -t <tag>" fail to print anything?
 3G.9	"cvs history -a -o" only printed one line for each checked-out
	module.  Shouldn't it print all the directories where the
	modules are checked out?
=3G.10	I can't figure out "history", can you give me concrete examples?

----------------
-- Section 3H --	"import", "im", "imp"
----------------
=3H.1	What is "import" for?
=3H.2	How am I supposed to use "import"?
=3H.3	Why does import put files on a branch?  Why can't you put it on
	the Main Trunk and let me work on a branch?
 3H.4	Is there any way to import binary files?
=3H.5	Why does "import" corrupt some binary files?
 3H.6	How do I keep "import" from expanding all the $\Revision$ strings
	to be 1.1.1.1?
#3H.7	I imported some files for the Yarg compiler that compiles files
	with a suffix of ".yarg" and whose comment prefix is "YARG> ".
	When I check them out, they will no longer compile because they
	have this junk in them.  Why?
 3H.8	How do I make "import" save the timestamps on the original files?
 3H.9	Why didn't "import" ignore the directories I told it to?
 3H.10	Why can't I "import" 3 releases on different branches?
 3H.11	What do I do if the Vendor adds or deletes files between releases?
 3H.12	What about if the Vendor changes the names of files or
	directories, or rearranges the whole structure between releases?
 3H.13	I thought "import" was for Vendor releases, why would I use it
	for code of my own?  Do I have to use import?
=3H.14	How do I import a large Vendor release?
+3H.15	Explain: ERROR: cannot create link to <file>: Permission denied

----------------
-- Section 3I --	"log", "lo", "rlog"
----------------
=3I.1	What is "log" for?
 3I.2	How do I extract the log entries between two revisions?
=3I.3	How do I extract the log entries on a whole branch?
 3I.4	How do I generate ChangeLogs from RCS logs?
=3I.5	Why does "log" tell me a file was committed exactly 5 hours later
	than I know it was?

----------------
-- Section 3J --	"patch", "pa", "rdiff"
----------------
 3J.1	What is "patch" for?
 3J.2	Why does "patch" include files from the Attic when I use '-D'?
 3J.3	How do I make "patch" produce a patch for one or two files?
	It seems to work only with modules.

----------------
-- Section 3K --	"release", "re", "rel"
----------------
 3K.1	What is "release" for?
 3K.2	Why does release -d delete directories within my directory that
	weren't ever in the CVS Repository?
 3K.3	Why can't I reverse a "cvs checkout path/name/subdir" with a
	"cvs release path/name/subdir" without an "unknown module name"?
 3K.4	Why can't I "release" portions of a checked out directory?  I
	should be able to "release" any file or sub-directory within
	my working directory.
 3K.5	I removed the tree that I was about to start working on.  How do I
	tell cvs that I want to release it if I don't have it anymore?
 3K.6	Why doesn't "release -d module" reverse a "checkout module"?
 3K.7	Why can't I release a module renamed with "cvs checkout -d"?

----------------
-- Section 3L --	"remove", "rm", "delete"
----------------
 3L.1	What is "remove" for?
 3L.2	Why doesn't "remove" work on directories when it appears to try?
 3L.3	I don't like removing files.  Is there another way to ignore them?
 3L.4	I just removed a file.  How do I resurrect it?
 3L.5	Why doesn't "remove" delete the file?  Instead, it prints:
	cvs remove: no files removed; use `rm' to remove the file first

----------------
-- Section 3M --	"rtag", "rt", "rfreeze"
----------------
 3M.1	What is "rtag" for?
 3M.2	Why would you use "rtag"?  It assumes a static Repository.

----------------
-- Section 3N --	"status", "st", "stat"
----------------
=3N.1	What is "status" for?
 3N.2	Why does "status" limit the File: at the top to 17 characters?
+3N.3	Shouldn't the status "Needs Checkout" be "Needs Update"?

----------------
-- Section 3O --	"tag", "ta", "freeze"
----------------
 3O.1	What is "tag" for?
=3O.2	What is the difference between "tag" and "rtag"?
=3O.3	Why does "tag -b" not put a tag on the Branch Point revision?
	How do I refer to the Branch Point?
-3O.4	So "tag" labels a bunch of files.  What do you use a Tag for?
 3O.5	How do I get "tag" and "rtag" to send mail the way "commit" does?
 3O.6	Why can't "tag" handle the '-r' option that "rtag" takes?
-3O.7	After a "tag <tag>" in my working directory, why doesn't "checkout
	-r <tag>" somewhere else produce copy of my current files?
#3O.8	Why doesn't "tag" write a history record the way "rtag" does?

----------------
-- Section 3P --	"update", "up", "upd"
----------------
 3P.1	What is "update" for?
=3P.2	What do 'U', 'M' and 'C' mean when I type "update"?  Are they
	different for "cvs -n update"?
 3P.3	What's the difference between "update" and "checkout"?
=3P.4	Why don't I get new files when I execute "update"?
#3P.5	Why does "update" say 'M' both for plain modified files and for
	successful (i.e. conflict-free) merges?  Aren't they different?
=3P.6	After a merge ("update" or "update -j"), why doesn't CVS remember
	the conflict and not allow you to commit the result until the
	conflict is resolved?
 3P.7	Is there a feature to tell me what I have changed, added and
	removed without changing anything?
=3P.8	Why does "cvs update" not flag directories that are not in the
	Repository as it does with new files?
 3P.9	Why are all my files deleted when I execute "update"?


===============================================
==  Section 4	====	Advanced Topics    ====
===============================================

----------------
-- Section 4A --	Installing CVS
----------------
#4A.1	What do I have to do before I install CVS?
 4A.2	How do I configure the CVS programs?
=4A.3	What do I have to install?
 4A.4	How do I get around the bugs I've heard of GNU diff version 2.2?

----------------
-- Section 4B --	Setting up and Managing the Repository
----------------
=4B.1	What do I do first?  How do I create a Repository?
=4B.2	What are those files in $CVSROOT/CVSROOT?
 4B.3	Is there any other state stored in the Repository besides in the
	$CVSROOT/CVSROOT directory?
 4B.4	How do I put sources into the Repository?
=4B.5	What file permissions should I use on (and in) the Repository?
=4B.6	How do I structure my Repository?
=4B.7	How do I manage the modules file?
 4B.8	Why would anyone use "modules"?  They are too restrictive.  I
	want to be able to select just the files I want to edit.
=4B.9	How do I rename a file or directory?  What are the consequences?
=4B.10	What are "Attic" directories?
 4B.11	Is it OK to remove anything from the Repository?
 4B.12	Can I convert to CVS from RCS without losing my revision history?
=4B.13	Can I move RCS files with branches in them into the Repository?
=4B.14	Can I use raw RCS commands on the Repository?
 4B.15	How do I convert from SCCS to RCS?
=4B.16	How do I limit access to the Repository?
=4B.17	What are the Repository Administrator's responsibilities?
 4B.18	How do I move the whole Repository?
+4B.19	How do I change permissions on a file in the Repository by using
	a CVS command?  (i.e. without using "chmod 777 $CVSROOT/dir/file")

----------------
-- Section 4C --	Branching
----------------
 4C.1	What is a branch?
=4C.2	Why (or when) would I want to create a branch?
=4C.3	How do I create and checkout a branch?
 4C.4	Once created, how do I manage a branch?
 4C.5	Are there any extra issues in managing multiple branches?
 4C.6	How do I merge a whole branch back into the trunk?
 4C.7	How do I merge changes from the trunk into my branch or between
	branches?
 4C.8	How do I add a new file to a branch?
=4C.9	How do I know what branch I'm (working) on?
 4C.10	Do I really have to know the name of the branch I'm working on?
 4C.11	How do I refer to the revision where I branched so I can see
	what changed since the Branch Point on another branch?
 4C.12	Why didn't the command "cvs admin -bBRANCH1 *" create a branch?
 4C.13	Is it possible to set the "default CVS branch" for everyone?
=4C.14	How do I perform a large merge?
 4C.15	Is a Vendor merge any different from a branch merge?
+4C.16	How do I go back to a previous version of the code on a branch?
+4C.17	Why do I get the latest files on the branch when I tried to
	"update -r <tag>"?

----------------
-- Section 4D --	Tricks of the Trade
----------------
=4D.1	How can you even check in binary files, let alone allow CVS to
	do its auto-merge trick on them?
 4D.2	Can I edit the RCS (",v") files in the Repository?
 4D.3	Can I edit the ./CVS/{Entries,Repository,Tag} files?
=4D.4	Someone executed "admin -o" and removed revisions to which
	tags/symbols were attached.  How do I fix them?
=4D.5	How do I move a magic branch tag?
 4D.6	Can I use RCS locally to record my changes without making them
	globally visible by committing them?
 4D.7	How can I allow access to the Repository by both CVS and RCS?
=4D.8	I "updated" a file my friend "bubba" committed yesterday.
	Why doesn't the file now have a modified date of yesterday?
#4D.9	While in the middle of a large "commit", how do I run other
	commands, like "diff" or "stat" without seeing lock errors?
 4D.10	Why does the merge occasionally resurrect lines of code?
 4D.11	Why does the merge fail when my "rcsmerge" program is
	configured to use GNU diff version 2.1 or later?
 4D.12	What the hell is Entries.Static?
=4D.13	Why did I get the wrong Repository in the loginfo message?
=4D.14	Can I have multiple source repositories, one for each project?
 4D.15	How do I run CVS setuid so I can only allow access through the
	CVS program itself?
 4D.16	How about using groups and setgid() then?
 4D.17	How do I use the "commitinfo" file?
 4D.18	How do I use the "loginfo" files?

----------------
-- Section 4E --	Weirdness
----------------
 4E.1	Explain: "ci error: unexpected EOF in diff output"
=4E.2	Explain: "RCS file /Repository/module/file.c,v is in use"
=4E.3	I don't want a Vendor branch.  Why can't I work on the main trunk?
 4E.4	Merges can't work.  I don't trust them.  If you won't change it to
	something I can understand, I won't use CVS.
 4E.5	Explain: "co error, line 2: Missing access list"
+4E.6	Explain: "error: RCS file name `xyz .c' contains white space"
+4E.7	Explain: cvs checkout: warning: <X> is not (any longer) pertinent

----------------
-- Section 4G --	Other Systems
----------------
 4G.1	I use a NeXT.  Is there anything I need to know?
 4G.2	I use OS/2.  Is there anything I need to know?
 4G.3	I use SCO Unix.  Is there anything I need to know?
 4G.4	I use AIX.  Is there anything I need to know?
=4G.5	I use IRIX.  Is there anything I need to know?
 4G.6	I use an HP system.  Is there anything I need to know?


=============================================
==  Section 5	====	Past & Future	 ====
=============================================

----------------
-- Section 5A --	Contributors
----------------
 5A.1	Who wrote CVS?
=5A.2	You didn't write all of this FAQ, did you?

----------------
-- Section 5B --	Bugs and Patches
----------------
 5B.1	Why can't CVS handle deletion of directories?
=5B.2	Why can't CVS handle the moving of sources from one place in the
	directory hierarchy to another?
=5B.3	Why does "checkout" recurse indefinitely if an alias contains
	its own name?
 5B.4	When I typed "cvs update -D <date>", why did it check out all
	sorts of ancient files from the Attic?  Shouldn't it just create
	the set of files and revisions that existed at that date?
 5B.5	When I typed "cvs update -D <date>" in my branch, why did it
	screw up all my files?
 5B.6	When I executed "checkout" into an existing directory I got "No
	such file or directory" errors.  Why?
 5B.7	Why does "update" send all output to the terminal after 26 files
	have been updated?
+5B.8	Why doesn't the "-I !" option work in update and import?

----------------
-- Section 5C --	Development
----------------
=5C.1	Where do I send bug reports?
=5C.2	Where do I send fixes and patches?
 5C.3	Where do I send ideas for future development?
 5C.4	What plans are there for fixing bugs?
=5C.5	What plans are there for new features?
=5C.6	I have some time and I'd like to help.  What can I do for you?


=================================================
==  Section 6	====	Table of Contents    ====
=================================================

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