From: NUNEZ@esevvx.cica.es (REGI's)
Newsgroups: comp.unix.questions
Subject: (none)
Date: 15 Oct 92 16:02:27 GMT

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1
14-OCT-1992 02:22:38.15
   1 00:00:00.00
15-OCT-1992 02:22:38.15
info-unix-request@sem.brl.mil
rafapa@obelix.cica.es

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Date:       Sat, 10 Oct 92 15:16:33 EST
From:       The Moderator (Mike Muuss) <Info-Unix-Request@BRL.MIL>
To:         INFO-UNIX@BRL.MIL
Reply-To:   INFO-UNIX@BRL.MIL
Subject:    INFO-UNIX Digest  V16#034

INFO-UNIX Digest          Sat, 10 Oct 1992              V16#034

Today's Topics:
                 Suggestions for good Unix5.4 tutorial.
   Re: Print files using printers belong to a different workstation?
                      Sending email to the States
               Re: Remote Printing from HP to BSD systems
       Re: Can you write/talk to a terminal which set "mesg -n"?
                               A QUESTION
                             Re: A QUESTION
                         Re: NT Under SCO Unix
           Looking for typing tutorial running under UNIX...
                Need public domain source control system
                           Re: IS UNIX DEAD?
                          Re: Unix Fax Servers
              Re: Need # of screen rows for shell variable
                                 <None>
                Re: passing output of ftp site to shell
                              Imakefile???
                 Re: BEGINNER Q.: redirection and awk?
                      UNIX physical memory control
                    Re: UNIX physical memory control
 Is there a Unix utility to determine memory usage of an application ?
                   Anon FTP almost setup - ls problem
                    Block size/Version No. question
                   Fortran compiler or f2c translator
                       Man page naming convention
                     Re: Man page naming convention
                              Login shell
                   Manipulating strings in batch file
                 Re: Manipulating strings in batch file
                   Re: Multiple Users for Windows/NT
                 Re: MIT X11R5 problem with SUID & SGID
                       changing control terminal
                              NFS problem?
                        Anyone can remove files
                      Re: Anyone can remove files
                     Profiling on shared library..
                   Re: Profiling on shared library..
                           Sockets and stuff
                         Re: Sockets and stuff
                   Re: Solbourne blues, in Boot minor
                     Re: comminicating with devices
            Welcome to comp.unix.questions [Monthly posting]
    Frequently Asked Questions about Unix (index) [Monthly posting]
     Frequently Asked Questions about Unix (1/4) [Monthly posting]
     Frequently Asked Questions about Unix (2/4) [Monthly posting]
     Frequently Asked Questions about Unix (4/4) [Monthly posting]
     Frequently Asked Questions about Unix (3/4) [Monthly posting]
                          Device driver (I/O)
         Printing to a serial postscript printer hangs printer.
                         When to use libcurses
                Problem with dd and tar file on exabyte
          Converting comp_t type to something more integerish.
                         Re: PC/NFS vs Netware
                prtvtoc (SVR4) vs. dkinfo (SUN OS 4.1.1)
                        kernel to nonkernel ipc
                                   rn
                  PKZIP for unix? (pkzip version 1.10)
-----------------------------------------------------------------

From: Ken McClaren <kmcclare@ncrclm.clemsonsc.ncr.com>
Subject: Suggestions for good Unix5.4 tutorial.
Date: 6 Oct 92 16:35:26 GMT
To:       info-unix@sem.brl.mil

I'm looking for a good UNIX 5.4 tutorial. Does anyone have any suggestions?
My background is in DOS.

        thanks in advance.
                ken.
P.S. please respond to my email address.

-- 

-----------------------------

From: Sascha Welter <sascha@sfb313.uni-kiel.dbp.de>
Subject: Re: Print files using printers belong to a different workstation?
Date: 7 Oct 92 02:08:42 GMT
Followup-To: comp.unix.questions
To:       info-unix@sem.brl.mil

Hi Dave,

at first, the -s flag from the lpr command is used to prevent the local
printer daemon from copying the users file to the printer queues spool area.
In Your case it will solve the problem, because the printer daemons don"t
share file systems.
	You have to contact both system administrators, from workstation1
and workstation2, to set up a remote printer queue. Let"s say the printer
queues for remote printing from workstation1 to workstation2 is named r12
and the queue for the opposit direction is named r21. Then You have to call
the printer by:
		  lpr -s -Pr12 <filename>
to print a file from workstation1 on the printer of workstation2.

I hope this will help a little bit....

Hasta pronto,  Sascha

-- 
 -------------------------------------------------------------------------------
sascha welter					  sascha@sfb313.uni-kiel.dbp.de
 -------------------------------------------------------------------------------

-----------------------------

From: "Mr. I. Rowland" <scst81@csc.liv.ac.uk>
Subject: Sending email to the States
Date: 7 Oct 92 10:51:23 GMT
To:       info-unix@sem.brl.mil

Keywords: 

I need to get in touch with someone at UCSC to find out if I can mail messages to a friend who is studying there. Does anybody know who to send the query to or how I can find out.

-----------------------------

From: Alan Yasutovich <yasu@ll.mit.edu>
Subject: Re: Remote Printing from HP to BSD systems
Date: 7 Oct 92 17:52:17 GMT
To:       info-unix@sem.brl.mil

In article <1992Oct7.073653.20235@autelca.ascom.ch> nbladt@autelca.ascom.ch (Norbert Bladt) writes:
>stevej@hpc.mentorg.com (Steve Jumonville) writes:
>
>
>>System V printing is painful to use if you're not familiar with it.
>Yes. I completely agree with this statement.
>
>>I suggest you use the menu driven 'sam' utility (System Admin Manager) to
>>set up printing to BSD. When you're in sam, follow the menu tree down through
>>peripherals, printers and plotters, to "setting up a remote printer". If you
>>have questions, use the "Help" funciton key.
>We solved it in a very simple way:
>	chown lp /usr/bin/lp
>	chmod u+s /usr/bin/lp	(now /usr/bin/lp is running as user "lp" !)
>This is necessary because on every *n*x system around there is an user "lp".
j(At least, on any *n*x system we have here, HP's, SUN's, Interactive UNIX, etc.)
>Now you can write a simple model/interface file which just does a remote shell
>on the other system and that's it.
>Something like
>	cat file | 'rsh BSDhost lp -Pbsd-printer-name'
>
>>By the way, run 'sam' in an 'hpterm' window if you want access to function keys.
>I guess, that you could do it with 'sam' on HP's, we never used it on
>System V.
>
>Hope this helps,
>
>Norbert.

	How about this. How do you print directly  to a printer
	which is on a terminal server.

	You need ip address and port address on the server.


		????

-- 
	Alan Yasutovich
	"inquiring  (and nosey) minds WANT TO KNOW!!!"
	I can remember when "safe sex" meant having a padded headboard!!
	Tick Tock.....Tick Tock......Tick Tock .....Tick Tock......

-----------------------------

From: Barry Margolin <barmar@think.com>
Subject: Re: Can you write/talk to a terminal which set "mesg -n"?
Date: 7 Oct 92 18:25:49 GMT
NNTP-Posting-Host: telecaster.think.com
To:       info-unix@sem.brl.mil

In article <1992Oct7.052622.940@monu1.cc.monash.edu.au> guest@monu1.cc.monash.edu.au) (Lost in C! :-) writes:
>Could anyone tell me that if we can write/talk to a terminal which
>set "mesg -n"?  I heard someone said that it is possible if we know
>which port to write to.  I'm very new to Unix and very confused.

No, you can't.  "Mesg -n" works by changing the permissions on the terminal
so that only the user can access it.

Acually, there are two exceptions: the superuser can write to anyone, and
if you're logged in as the same user who has turned messages off you can
write to him.
-- 
Barry Margolin
System Manager, Thinking Machines Corp.

barmar@think.com          {uunet,harvard}!think!barmar

-----------------------------

From: Sekhar Chitti <csc5840@hertz.njit.edu>
Subject: A QUESTION
Date: 7 Oct 92 21:23:28 GMT
To:       info-unix@sem.brl.mil





Hi netters,

I have a question on using 'sed' and 'awk' to edit a text file.
I have a text file of nearly 500 lines and having 6 fields.
Now that I wanna delete the last 5 fields of each line and 
keep only the first one. What is the easiest way I can do this? 
I am a bit familiar with sed and awk. But don't know exactly
how I can use them to do this? Could anybody help me in this
regard? Thanks.

Sekhar 
csc5840@hertz.njit.edu

-- 
Sekhar P Chitti
381 Broad Street, Apartment #2109-A,
Newark, NJ - 07104
Phone # 201-482-2801 (res)

-----------------------------

From: John Gordon <gordon@osiris.cso.uiuc.edu>
Subject: Re: A QUESTION
Date: 8 Oct 92 04:56:50 GMT
To:       info-unix@sem.brl.mil

csc5840@hertz.njit.edu (Sekhar Chitti) writes:

>Hi netters,

>I have a question on using 'sed' and 'awk' to edit a text file.
>I have a text file of nearly 500 lines and having 6 fields.
>Now that I wanna delete the last 5 fields of each line and 
>keep only the first one. What is the easiest way I can do this? 
>I am a bit familiar with sed and awk. But don't know exactly
>how I can use them to do this? Could anybody help me in this
>regard? Thanks.

	% cat datafile | awk '{print $1}'

	(Of course, this assumes that spaces are the field separator.  If
some other character is the field seperator, insert a -F<char> right after
the awk.)

---
John Gordon                        My incredibly witty saying has been 
gordon@osiris.cso.uiuc.edu         Politically Corrected into oblivion.

-----------------------------

From: John Ellithorpe <jdell@zenobia.mit.edu>
Subject: Re: A QUESTION
Date: 8 Oct 92 22:58:47 GMT
To:       info-unix@sem.brl.mil

On 7 Oct 92 21:23:28 GMT, csc5840@hertz.njit.edu (Sekhar Chitti) said:
> Nntp-Posting-Host: hertz.njit.edu
> Hi netters,

> I have a question on using 'sed' and 'awk' to edit a text file.
> I have a text file of nearly 500 lines and having 6 fields.
> Now that I wanna delete the last 5 fields of each line and 
> keep only the first one. What is the easiest way I can do this? 
> I am a bit familiar with sed and awk. But don't know exactly
> how I can use them to do this? Could anybody help me in this
> regard? Thanks.

All you need is:

awk '{print $1}' < input-file > output-file

and there you have it.

John
--

===============================================================================
John Ellithorpe                           | Internet: jdell@maggie.mit.edu
Dept. of Physics, Rm 26-349               | Phone   : (617) 253-3074  Office
Massachusetts Institute of Technology     |           (617) 253-3072  Lab
Cambridge, MA  02139                      |           (617) 236-4910  Home
===============================================================================

-----------------------------

From: Rob <rdorich@jade.tufts.edu>
Subject: Re: A QUESTION
Date: 9 Oct 92 23:09:12 GMT
To:       info-unix@sem.brl.mil

Since nobody suggested cut...
how about:

cat file | cut -d' ' -f1

Note that you can change the delimeter (-d) to whatever you want to,
here I set to space.

Rob
--

 -------------------------------------------------------------------------------
Roberto Dorich           |           /~~  \ /  ~~/~~ /~~/  /~~  /|  /    /~~
                         |    SKI   /--    X    /   /__/  /--  / |/ |   /--
rdorich@jade.tufts.edu   |         /__    / \  /   /\    /__  /     |  /__
 -------------------------------------------------------------------------------

-----------------------------

From: Alistair Banks <alistair@microsoft.com>
Subject: Re: NT Under SCO Unix
Date: 7 Oct 92 21:44:06 GMT
To:       info-unix@sem.brl.mil

May I request that this thread is taken over to .advocacy groups. It
has degenerated irretrievably from an questions about plans into a
debate about the realtive merits of UI techniques - this is way off
the subject matter of Win32 API programming.

-- Alistair

-----------------------------

From: Nitin Borwankar <nitin@ingres.com>
Subject: Re: NT Under SCO Unix
Date: 9 Oct 92 21:55:13 GMT
To:       info-unix@sem.brl.mil

In article <1992Oct07.214406.28902@microsoft.com> alistair@microsoft.com (Alistair Banks) writes:
>May I request that this thread is taken over to .advocacy groups. It
>has degenerated irretrievably from an questions about plans into a
>debate about the realtive merits of UI techniques - this is way off
>the subject matter of Win32 API programming.
>
>-- Alistair

Thank you!! YES !!

Nitin Borwankar,
nitin@ingres.com 	**** visualize whirled peas ****

-----------------------------

From: William Daul <billd@informix.com>
Subject: Looking for typing tutorial running under UNIX...
Date: 7 Oct 92 22:12:11 GMT
Originator: billd@cheetah
To:       info-unix@sem.brl.mil

Is there such a shareware application?  How about a $$$-ware application?

Thanks,  --Bill
-- 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 William Daul             Advanced Support      INFORMIX SOFTWARE INC.
 4100 Bohannon Dr.        (415) 926-6488 - wk
 Menlo Park, CA. 94025    uunet!infmx!billd  or  billd@informix.com

-----------------------------

From: Proactive Software <proact@netcom.com>
Subject: Need public domain source control system
Date: 7 Oct 92 23:24:53 GMT
To:       info-unix@sem.brl.mil

My company is using the SCCS for now and we have tried to look into
PVCS but it is too expensive.

I will appreciate any information about public domain source control
system: where to get the source code, etc.
I am also looking for RCS and converter to convert SCCS format to RCS
format.

Please reply by e-mail as I don't have good Usenet News access.
Thank you.

Lak Ming Lam
lml@proactive.com

-----------------------------

From: Daniel Smith <dansmith@autodesk.com>
Subject: Re: IS UNIX DEAD?
Date: 8 Oct 92 00:48:24 GMT
To:       info-unix@sem.brl.mil

In <5864@ucsbcsl.ucsb.edu> harley@engrhub.ucsb.edu (Harley Hahn) writes:
> What do you think about the question "Is Unix Dead?"  What would
> you tell someone who asks if this is true?

	I think it's heading that way, but "not yet".  Most of the
problem seems to be endless bickering among the different vendors
of OS's and GUI's.  I've been around Unix for 10 years, and am
starting to feel like that's enough, waiting for it to really get its
act together.  I'm going to slant my future learning efforts towards NT.

	C'mon guys, the Unix pie isn't that big to support so much
in-fighting.  At the moment, it looks like a slice of lemon, cherry,
blueberry...  Think of this:  if just 10% of approximately 100 million
DOS users switch to NT in the next three years, that's what, a bigger
slice than any of the existing Unix vendors? any two or three of them
put together?

	Cooperate, don't Litigate.

				Daniel
-- 
     Daniel Smith, Autodesk, Sausalito, California, (415) 332-2344 x 2580
	      Disclaimer: written by a highly caffeinated mammal
	    dansmith@autodesk.com            dansmith@well.sf.ca.us

-----------------------------

From: Fred Rump from home <fr@compu.com>
Subject: Re: IS UNIX DEAD?
Date: 8 Oct 92 15:16:17 GMT
To:       info-unix@sem.brl.mil

dansmith@Autodesk.COM (Daniel Smith) writes:

>	C'mon guys, the Unix pie isn't that big to support so much
>in-fighting.  At the moment, it looks like a slice of lemon, cherry,
>blueberry...  Think of this:  if just 10% of approximately 100 million
>DOS users switch to NT in the next three years, that's what, a bigger
>slice than any of the existing Unix vendors? any two or three of them
>put together?

Somehow that thought process is pervasive thruout computerland. But why?

Is it because most people think you must sit in front of a computer in order
to use it?  How many users are there on the typical SCO system for example?

One OS, one box - maybe 10 users?

Take the 600 or 700 hundred thousand SCO licenses out there and multiply. And 
that's only SCO. Add all the minis from everybody who run UNIX and then add 
the workstations somewhere at the end. The workstations like SUNs are the 
smallest quantity of the bunch - but they represent big bucks to SUN as they 
are expensive.

So SUN has what, 2 billion in sales? And SCO has 160 million. But they are 
nowhere equal in actual number of users.  SCO is much bigger in that regard.

If I can recall correctly bith have roughly the same number of UNIX licenses 
out there except that SCO hangs lots of terminals on theirs and SUN stands 
alone.

So 10 million NT users are nothing to brag about just yet. By then the number 
of UNIX users will certainly also have grown. 

fred

-- 
W. Fred Rump 	office:	   fred@COMPU.COM     'mans feet have grown/so big 
26 Warren St.   home: fred@icdi10.compu.com  that he/forgets his littleness'
Beverly, NJ. 08010                          		Don Marquis 
609-386-6846    bang:uunet!cdin-1!icdi10!fr   

-----------------------------

From: Gene Kochanowsky <gene@aee.aee.com>
Subject: Re: IS UNIX DEAD?
Date: 9 Oct 92 17:49:53 GMT
To:       info-unix@sem.brl.mil

fr@compu.com (Fred Rump from home) writes:

>dansmith@Autodesk.COM (Daniel Smith) writes:

>>	C'mon guys, the Unix pie isn't that big to support so much
>>in-fighting.  At the moment, it looks like a slice of lemon, cherry,
>>blueberry...  Think of this:  if just 10% of approximately 100 million
>>DOS users switch to NT in the next three years, that's what, a bigger
>>slice than any of the existing Unix vendors? any two or three of them
>>put together?

>Somehow that thought process is pervasive thruout computerland. But why?

>Is it because most people think you must sit in front of a computer in order
>to use it?  How many users are there on the typical SCO system for example?

>One OS, one box - maybe 10 users?

>Take the 600 or 700 hundred thousand SCO licenses out there and multiply. And 
>that's only SCO. Add all the minis from everybody who run UNIX and then add 
>the workstations somewhere at the end. The workstations like SUNs are the 
>smallest quantity of the bunch - but they represent big bucks to SUN as they 
>are expensive.

>So SUN has what, 2 billion in sales? And SCO has 160 million. But they are 
>nowhere equal in actual number of users.  SCO is much bigger in that regard.

>If I can recall correctly bith have roughly the same number of UNIX licenses 
>out there except that SCO hangs lots of terminals on theirs and SUN stands 
>alone.

>So 10 million NT users are nothing to brag about just yet. By then the number 
>of UNIX users will certainly also have grown. 

	Camon guys! This sort of discussion is nonsense. The more people that 
	use computers, the more ways computers will be used. One size does not 
	fit all, and never will. Unix, in some form or another, will be around 
	for some time to come, so will WindowsNT, DOS, MacOS, and so on. From 
	what I understand there are still die hard CPM users out there. I
	strongly suspect that the operating system of the future will be none
	of these, but something completely different.

Gene Kochanowsky
gene@aee.com
-- 
Gene Kochanowsky                           | "And remember ....
Associated Electronic Engineers, Inc.      |       The better you look ... 
(904)893-6741 Voice, (904)893-2758 Fax     |       the more you will see."
gene@aee.com                               |               Miss Lidia

-----------------------------

From: Steve Elias <eli@spdcc.com>
Subject: Re: Unix Fax Servers
Date: 8 Oct 92 01:03:16 GMT
To:       info-unix@sem.brl.mil


 sl@wimsey.bc.ca (Stuart Lynne) writes:
> eli@spdcc.com (Steve Elias) writes:
>>those concerned with legalities might want to 
>>note that faxback is a patented thang (IFF the fax is
>>sent out via a separate phone call.)
>
>We'll also note that there are several good examples of the technology
>concerned that pre-date the patent application date that should lead to
>the patent being thrown out if and when it gets to court. 

i think that's absolute hogwash, but to each his own.

>The patent covers use of signals (i.e. DTMF tones) to control the delivery
>of faxes from a computer system.

i think the above statement overstates what the patent covers.

> For example, Globefax a service like this 
>was in place and being offerred commercially in Canada in January of 1988 by
>Teleglobe Canda.  The patent application date is May 11, 1988.

sorry, but i reject your armchair patent lawyering and do not
want to engage in that any more than i've already done.

let's let the lawyers deal with that crap elsewhere
and keep only the crucial tech info here, eh?  in this case, 
the crucial info is that there is a patent.  

>I've only been peripherally involved so I don't have uptodate details
>but it's my understanding that there is currently an industry group that
>will be sponsoring a challenge.

you've gotta be kidding.
an industry group?  why would it take an "industry group" to fight 
such a nice little fish company's patent?  (rhetorical question).

/eli
-- 
/* eli@spdcc.com */

-----------------------------

From: Patrick Goebel <patrick@casbs.stanford.edu>
Subject: Re: Need # of screen rows for shell variable
Date: 8 Oct 92 02:21:46 GMT
To:       info-unix@sem.brl.mil


Earlier I asked the net:

> I need to determine the number of rows on a user's terminal screen for
> a shell script I am writing.  

Many thanks for all the ingenious answers.  Here a few in case you
need one yourself some day.

(1) rows=`echo $TERMCAP | sed 's/.*:li#\([0-9][0-9]*\):.*/\1/'`

(2) hmm...our HPs have environment variables that are called LINES and
    COLUMNS that do what you want...

(3) tput cols
    tput lines

    Reads terminfo. Works in SysVr3 from SCO.

And my favorite (i.e. the one I will use):

(4) stty size | awk '{ print $1 }'

    works for me on SUNOS4.1.2, CONVEX(argh), and UNICOS (Cray YMP)
    systems.


Cheers,
patrick
--
Patrick Goebel                    E-MAIL: patrick@casbs.Stanford.EDU
Network Administrator             VOICE:  (415) 321-2052
CASBS, 202 Junipero Serra Blvd.   FAX:    (415) 321-1192
Stanford, CA 94305                BEEPER: Temporarily Out of Order...

-----------------------------

From: gmhtng@v9000.ntu.ac.sg
Subject: <None>
Date: 8 Oct 92 02:27:39 GMT
To:       info-unix@sem.brl.mil

Hi there,

I have just installed AT&T UNIX System V Rel 4 into my 486 PC and I am having
problems making use of my serial port (ie com1) to communicate with PLC or
robot controller. (I could not open the special file /dev/tty00 which is
configured as the serial port). I believe that I have not configured the system
properly.

I would appreciate it if you could enlighten me. Thank for the enlightment in
advance.   

-----------------------------

From: Bill the CAT <wessir@stein.u.washington.edu>
Subject: Re: passing output of ftp site to shell
Keywords: shell, csh, scripts, ftp
Date: 8 Oct 92 03:21:26 GMT
To:       info-unix@sem.brl.mil

How can you pass ftp remote output to a csh script?

-----------------------------

From: unknown <hemstree@cs.colostate.edu>
Subject: Imakefile???
Date: 8 Oct 92 03:31:52 GMT
To:       info-unix@sem.brl.mil


What is Imake and where can I get the source to use some Imakefiles
that I have (came with some programs that I ftp'd).

Thanks for the help,

Charles
--
!===========================================================================!
! Charles H. Hemstreet IV       !internet: hemstree@handel.cs.Colostate.Edu !
! Colorado State University     !        Professional College Student       !
!===========================================================================!

-----------------------------

From: John Gordon <gordon@osiris.cso.uiuc.edu>
Subject: Re: BEGINNER Q.: redirection and awk?
Keywords: cd,prompt,path,pwd
Date: 8 Oct 92 04:52:13 GMT
To:       info-unix@sem.brl.mil

dcullen@eng.clemson.edu (david cullen) writes:

>I hate asking this, but i've forgotten how to do it in unix.

>How can I get my working directory to show up in my prompt?

	1) Set your prompt to have a pwd command embedded in it
	2) Alias 'cd' so that it re-sets your prompt to the new directory
	3) Also alias any other dir-changing commands, such as pushd, popd

-----------------------------

From: Graham Hausler <hausler@aldetec.oz.au>
Subject: UNIX physical memory control
Date: 8 Oct 92 08:45:53 GMT
To:       info-unix@sem.brl.mil

I require some information concerning device drivers and UNIX memory
manipulation.
 
I am developing a VME device driver on a MVME187 System V/88 system (R3V7)
and wish to map some of the physical memory to the VME space. I have had
a look at the device driver documentation and cannot see how I can 'remove'
pages of UNIX physical memory from the system so I can use it on the VME
bus. Am I wrong in thinking that a device driver cannot lock/reserve physical
memory from the UNIX free memory lists ? Alternatively, I have seen 
reference to the device /dev/kmem (and /dev/mem ??) at various times, does
this device allow me to modify the physical memory available to UNIX ? If so,
where do I obtain information on controlling/accessing this device ? Are
there any other alternatives ?

Please email any responses directly, I will post a summary if requested.

Thanks 
Graham Hausler.



-- 
Internet:   hausler@aldetec.oz.au      --> GEMCO, Perth, Australia.

-----------------------------

From: Jack Craig <jack@admin.mport.com>
Subject: Re: UNIX physical memory control
Date: 9 Oct 92 19:55:51 GMT
Followup-To: comp.unix.questions
To:       info-unix@sem.brl.mil

hausler@aldetec.oz.au (Graham Hausler) writes:

>I require some information concerning device drivers and UNIX memory
>manipulation.
> 
>I am developing a VME device driver on a MVME187 System V/88 system (R3V7)
>and wish to map some of the physical memory to the VME space. I have had
>a look at the device driver documentation and cannot see how I can 'remove'
>pages of UNIX physical memory from the system so I can use it on the VME
>bus. Am I wrong in thinking that a device driver cannot lock/reserve physical

is there a reason you cant sptalloc(count, foo...)

in your xx_init() routine. usually the best time to grab that suff is when
you're booting. find some ddi/ddk doc on sptalloc(), sptfree()

=============================================================================
 Jack Craig  Microport         SVR4 408-438-UNIX   uunet!mport.com!jack
             Software Horizons SVR3 408-684-1375   uunet!sco.com!blznrzn!jack
=============================================================================

>-- 
>Internet:   hausler@aldetec.oz.au      --> GEMCO, Perth, Australia.

-----------------------------

From: brehonyt@ul.ie
Subject: Is there a Unix utility to determine memory usage of an application ?
Date: 8 Oct 92 13:40:47 GMT
To:       info-unix@sem.brl.mil



Can anybody out there in Internetland tell me if there is a Unix 
utility available that can analyse/determine memory usage & allocation
of an application at run-time. Something that runs in the background
while the application runs in the foreground perhaps.

Does something like this exist ?. If so, is it freeware/shareware 
and where can I find it. 

Thanks in advance.

Tom Brehony.
University of Limerick, Ireland.
Email : brehonyt@ul.ie

-----------------------------

From: michael a migdol <mmigdol@ccwf.cc.utexas.edu>
Subject: Anon FTP almost setup - ls problem
Date: 8 Oct 92 15:47:24 GMT
Followup-To: comp.unix.questions
Originator: mmigdol@grumpy.cc.utexas.edu
To:       info-unix@sem.brl.mil

I'm trying to setup anon. ftp on my Dell 486 running Dell sysvR4. Everything
seems to work ok so far - I can log in ok, move around the directory structure,
get files, etc. But when I ls, I don't get any output; I get the standard
"Opening ASCII connection message", but it transmits 0 bytes. I've checked and
double checked all my modes, tried putting copies of the ls executable in
~ftp, ~ftp/bin, and ~ftp/usr/bin, all to no avail.

Dell's Tech support, as well as my college's tech support haven't been able to
figure this one out.

Does anyone out there have any suggestions?

Thanx in advance...
Michael (please respond by mail if possible)

-----------------------------

From: Ken Beer <kbeer@wam.umd.edu>
Subject: Block size/Version No. question
Date: 8 Oct 92 16:39:46 GMT
To:       info-unix@sem.brl.mil


 I working on an old system with no man pages and a scarcity of gurus.
I would like to know the block size for the tape drive.  Is there any way
to do this from UNIXtm? (i.e. without having to take apart the drive
or sending away for long forgotten manuals?)

Also, is there a way to determine which version of Unix you are using
directly, withosing some technique like, "It supports aliasing, it 
must be Sys.V" or whatever?

THANKS,

	
-- 
 				
				- |< E /\/  

 kbeer@wam.umd.edu

-----------------------------

From:  WSHB Operations Eng <michaelb@wshb.csms.com>
Subject: Fortran compiler or f2c translator
Date: 8 Oct 92 17:42:55 GMT
Followup-To: poster
To:       info-unix@sem.brl.mil

Help! I've got an old Fortran program that is for VMS. I want to get it
running on an SCO Xenix box, but I don't know too much about Fortran, nor
do I have a Fortran compiler. The source code is one giant file, not a
bunch of small modules like I'm used to, and it's a little over 400 pages
long once I print it out.

Does anyone have any recommendations about how to proceed. I know there is
a translator named f2c available on some archive. Does it really work very 
well with something this size. I really can't spend the time to sit down 
and piece it together by myself, even if I had the experience in C to try 
something so foolish. I do have gcc if it would be better than cc to deal 
with the output of f2c.

As an alternative, is there some Fortran compiler out there I could grab
off an archive and get working. Or would I be forced to buy a comercial
compiler? Is Fortran standard enough that I could probably get it running
on Xenix without a lot of debugging if I can get a compiler?

Or, maybe, is it cheaper to just get an old microvax from somewhere and get
it running in the environment it was designed for? How many $$ would I be
looking at to get a used machine and licenses to get it going?

Thanks in advance,
Michael
-- 
Michael Batchelor--Systems/Operations Engineer #compliments and complaints
WSHB - An International Broadcast Station of   #   letterbox@csms.com
       Herald Broadcasting Syndicate, Inc.     #technical questions and reports
michaelb@wshb.csms.com         +1 803 625 5552 #   letterbox-tech@csms.com

-----------------------------

From: Barry Margolin <barmar@think.com>
Subject: Man page naming convention
Date: 8 Oct 92 17:54:04 GMT
NNTP-Posting-Host: telecaster.think.com
To:       info-unix@sem.brl.mil

This is the kind of silly question I usually answer, but now I've come up
with one of my own....

Why does the man command require the section number of the man page entry
to be in the file name suffix, when it's already in the directory name?
One possibility I considered is that it would allow you to link all the
man<section> directories together if you wanted; however, I'm under the
impression that the naming convention predates symbolic links (the only
directory links that are normally permitted).
-- 
Barry Margolin
System Manager, Thinking Machines Corp.

barmar@think.com          {uunet,harvard}!think!barmar

-----------------------------

From: Barry Margolin <barmar@think.com>
Subject: Re: Man page naming convention
Date: 8 Oct 92 20:12:23 GMT
NNTP-Posting-Host: telecaster.think.com
To:       info-unix@sem.brl.mil

In article <1992Oct8.183108.21963@news.eng.convex.com> tchrist@convex.COM (Tom Christiansen) writes:
>:Why does the man command require the section number of the man page entry
>:to be in the file name suffix, when it's already in the directory name?

>One reason is that people can have one man3 directory that contains
>both system.3 (or 3c) and system.3f, just to name one scenario.

I considered that, but why couldn't that be /usr/man/man3/system and
/usr/man/man3/system.f?  Also, did they have the lettered subsections when
the naming convention was started?

-- 
Barry Margolin
System Manager, Thinking Machines Corp.

barmar@think.com          {uunet,harvard}!think!barmar

-----------------------------

From: "Peter F. Couvares" <pfcouvar@unix.amherst.edu>
Subject: Re: Man page naming convention
Date: 9 Oct 92 03:43:29 GMT
To:       info-unix@sem.brl.mil

barmar@think.com (Barry Margolin) writes:
> Why does the man command require the section number of the man page entry
> to be in the file name suffix, when it's already in the directory name?

	I'm by no means a unix-guru, but in my experience setting up a
Linux system, the .2 or .1 helped indicate where a man page should be placed.
Although you could always look in the file itself, it's a lot easier to
type "mv *.2 /usr/man/man2" when you have a few dozen to sort. Just a guess...

-Peter

pfcouvar@unix.amherst.edu (Peter Couvares)

-----------------------------

From: Bill Campbell <bill@celestial.com>
Subject: Re: Man page naming convention
Date: 10 Oct 92 02:16:05 GMT
To:       info-unix@sem.brl.mil

In <1b24n7INN3l0@early-bird.think.com> barmar@think.com (Barry Margolin) writes:

:In article <1992Oct8.183108.21963@news.eng.convex.com> tchrist@convex.COM (Tom Christiansen) writes:
:>:Why does the man command require the section number of the man page entry
:>:to be in the file name suffix, when it's already in the directory name?

:>One reason is that people can have one man3 directory that contains
:>both system.3 (or 3c) and system.3f, just to name one scenario.

:I considered that, but why couldn't that be /usr/man/man3/system and
:/usr/man/man3/system.f?  Also, did they have the lettered subsections when
:the naming convention was started?

The main reason I can see for using the .<number> suffix is that
I usually write all the man pages in a directory other than /usr/man...
and it helps to determine where to put them when I'm done.

Bill
-- 
INTERNET:  bill@Celestial.COM   Bill Campbell; Celestial Software
UUCP:   ...!thebes!camco!bill   6641 East Mercer Way
             uunet!camco!bill   Mercer Island, WA 98040; (206) 947-5591
SPEED COSTS MONEY -- HOW FAST DO YOU WANT TO GO?

-----------------------------

From: Stefan Monnier <osoelgaultier+@cmu.edu>
Subject: Login shell
Date: 8 Oct 92 18:36:59 GMT
To:       info-unix@sem.brl.mil


How can I know in .cshrc if csh has been started as a login shell ?

	Stefan

 -----------------------------------------------------
-- On the average, people seem to be acting normal --
 -----------------------------------------------------

-----------------------------

From: "David K. Codelli" <codelli@cyclone.mitre.org>
Subject: Manipulating strings in batch file
Date: 8 Oct 92 19:25:31 GMT
To:       info-unix@sem.brl.mil

I am writing a batch file that runs awk on a file that has a name of the form:

prefix.input

I want to write the output to a file of the form

prefix.output

(Prefix is variable)  How can I screen off the prefix in my batch file?

i.e.

#!/bin/sh
inputfilename=$1
outputfilname= <take output suffix and add "output">
awk ... > outputfilename

Thanks!

-- 
David K. Codelli            The opinions stated here are mine
The MITRE Corporation       only, and not necesssarily those 
dcodelli@mitre.org	    of my employer.

-----------------------------

From: John Ellithorpe <jdell@nefertiti.mit.edu>
Subject: Re: Manipulating strings in batch file
Date: 10 Oct 92 04:20:02 GMT
To:       info-unix@sem.brl.mil

On Thu, 8 Oct 1992 19:25:31 GMT, codelli@cyclone.mitre.org (David K. Codelli) said:
> Nntp-Posting-Host: cyclone.mitre.org

> I am writing a batch file that runs awk on a file that has a name of the form:
> prefix.input
> I want to write the output to a file of the form
> prefix.output
> (Prefix is variable)  How can I screen off the prefix in my batch file?
> i.e.
> #!/bin/sh
> inputfilename=$1
> outputfilname= <take output suffix and add "output">
> awk ... > outputfilename

> Thanks!

If input and output are fixed, then you can just use the basename command:

#!/bin/sh
inputfilename=$1
outputfilename=`basename $1 .input`.output
awk ... > outputfilename

and that's it.

John
--

===============================================================================
John Ellithorpe                           | Internet: jdell@maggie.mit.edu
Dept. of Physics, Rm 26-349               | Phone   : (617) 253-3074  Office
Massachusetts Institute of Technology     |           (617) 253-3072  Lab
Cambridge, MA  02139                      |           (617) 236-4910  Home
===============================================================================

-----------------------------

From: Brian Vetter <bjv@shasta.tivoli.com>
Subject: Re: Multiple Users for Windows/NT
Date: 8 Oct 92 19:26:41 GMT
Followup-To: comp.unix.dos-under-unix
To:       info-unix@sem.brl.mil

Alistair Banks writes:

|> Both the microkernel and the Win32 subsystem know how to handle multile
|> users. The piece that won't is the server that managers the screen, being
|> a part of the Win32 subsystem. So you can have multiple background
|> tasks with different security IDs, but only one security ID for
|> interactive processes -- Alistair

Frankly, I don't know what you are getting at.  I'm sitting here at my
Sparcstation (running SunOs of course) and I can "graphically" create new
windows and run programs from my window manager - BUT ONLY AS THE USER ID
I have logged in as.  So Unix/X window managers don't provide such a facility
either.  The special "trick" to run a "graphical" program as
another user is to create a shell/command window, su, and then crank up
the "windowing" program from there.

So are you suggesting that someone can't run a "shell" in a window (not
a dos shell) as an app, spawn another shell within that window with a
different user id (su or login equivalent), and then run other
"interactive" programs from that shell with that user id?  Does the Win32
window "server" not allow this other "interactive" process to create
new windows because of a different security ID (no xhost-like mechanism)?

Brian Vetter
bjv@tivoli.com

-----------------------------

From: Bob Myers <stssram@st.unocal.com>
Subject: Re: MIT X11R5 problem with SUID & SGID
Date: 8 Oct 92 21:37:46 GMT
To:       info-unix@sem.brl.mil

In article <1992Oct6.200839.19337@nmt.edu> kelly@nmt.edu (kelly) writes:

kelly> My next beef has to do with the `install' target and SUN-DES-1
kelly> authorization.  The mit `install' target installs xterm as set-uid
kelly> root, so it can update the /etc/utmp file.

kelly> However, a program that runs set-uid root uses root's key on the local
kelly> machine rather your key, rendering SUN-DES-1 authorization only useful
kelly> for useless clients like xclock, xman, ... .  You can't run xterms.

kelly> The fix: install xterm as set-gid tty, not set-uid root, and make sure
kelly> /etc/utmp is group-writable by group tty.  Then, an xterm runs with
kelly> your user ID, so it uses your key for SUN-DES-1, and you've got the
kelly> protection you were after.

Hmmm.  This doesn't do everything the suid bit did, though.  A suid root
xterm will change the ownership of the tty to the appropriate user, preventing
other users from reading/writing there, etc.  Your "fix" won't be able to do
this.

Maybe the way this should work is to use the SUN-DES-1 key for the real
uid, not the key for the effective uid.  This is really a SUN-DES-1/suid
problem, not an install problem.

--
Bob Myers                              Unocal Science & Technology Division
Internet: Bob.Myers@st.unocal.com      Seismic Research and Applications
Phone: [714] 693-6951                  P. O. Box 68076
                                       Anaheim, California 92817-8076

-----------------------------

From: "yung-kao.hsu" <ykhsu@cbnewsf.cb.att.com>
Subject: changing control terminal
Date: 8 Oct 92 21:48:22 GMT
To:       info-unix@sem.brl.mil


We encounter the following problem and appreciate any information
in solving it. Here is the problem:

	We have a group of processes who frequently open and close
	terminal devices for external communications. Since control
	terminal associated with each process is determined by the
	first device it opened after setpgrp() call or it first
	started (according to some UNIX documents), to make sure signal
	handling won't get messed up, these process will call setpgrp()
	each time they close and open a tty device (only one device is
	opened at any time).

	Despite that, we continue to see many of these processes
	shared the same control terminal when we do a "ps" command.
	The ingoblem seems to us is that using setpgrp() only allow
	us to set the control terminal for ONCE; any subsequent
	calls and device opening will not be able to affect this
	in the same process.

	I wonder if anyone encountered such a problem before and what
	was the solution besides forking. I appreciate any responses.

Yung-Kao Hsu
PS: I am not a regular subscriber to this group; forgive me if it has been
frequently asked or this is the wrong group to post.

-----------------------------

From: Dusit Tansathein <ddt@mdi.gwinnett.com>
Subject: NFS problem?
Date: 8 Oct 92 22:21:41 GMT
To:       info-unix@sem.brl.mil

Hi,

I get the following message on the console of our NCR-3447 running UNIX SVR4.2:
"WARNING: dlpi.c: ILD: could not allocb DL_UNITDATA_IND".  My questions are:

1) Does this have something to do with NFS (our NCR is the NFS server)? 
2) Can it cause the system to hang?
3) If you experienced the same problem, what would be the best solution?

Any information would be appreciated.

Thanks,

Duke-The (scsi) Terminator, ddt@mdi.gwinnett.com (Dusit Tansathein)

-----------------------------

From: Sean Coleman 497-5672  <coleman@bldrdoc.gov>
Subject: Anyone can remove files
Date: 8 Oct 92 22:51:23 GMT
Originator: coleman@deputy
To:       info-unix@sem.brl.mil


If a directory has the permissions drwxrwxrwx and there
exists a file in the directory owned by user A with
permissions rw-------, why should anyone be allowed to
remove the file? Does the directory permissions have 
precendence over file permissions? I would of thought
that eventhough the directory has write permissions for 
the group and other, they still shouldn't be able to 
remove the file since only the owner can read and write.

Thanks

Sean Coleman
coleman@bldrdoc.gov

-----------------------------

From: Thomas Richard Stevenson <tom@uts.cc.wayne.edu>
Subject: Re: Anyone can remove files
Date: 9 Oct 92 03:16:03 GMT
To:       info-unix@sem.brl.mil

coleman@bldrdoc.gov (Sean Coleman 497-5672 ) writes:


>If a directory has the permissions drwxrwxrwx and there
>exists a file in the directory owned by user A with
>permissions rw-------, why should anyone be allowed to
>remove the file? Does the directory permissions have 
>precendence over file permissions? I would of thought
>that eventhough the directory has write permissions for 
>the group and other, they still shouldn't be able to 
>remove the file since only the owner can read and write.

There are two different permissions here. The file permissions
control what a user can do with the data within the file. It
does NOT control what a user can do with the file it's self.

The dir permissions control what a user can do with the file. It
does NOT control what a user can do with the data within the file.

Between the two permissions, the complete file/data permission is
created. So if you want to permit a file Read/Write, you change
the access to the file. If you want to permit the file Create/Destroy,
you change the access to the directory the file is in. 

Lets say you chown a file to someone else, and the access on the
file was 700. You would not be able to read or write the file. 
You would not be able to change the owner back to you (or anyone
else). You would not be able to change the access to something
you did have access to, but if you still had R/W access to the
directory that file was in, you would be able to destroy it, because
destroy access has to do with the dir access, not the file access, or
file owner.

-- 
     ____  __   __       Tom@UTS.CC.Wayne.Edu
      /   /_/  /_        Thomas_Richard_Stevenson@MTS.CC.Wayne.Edu
     /.  /\ . __/.       Tom@CMS.CC.Wayne.Edu
                         UserTom@WayneMTS.Bitnet

-----------------------------

From: Thomas Koenig <ecmtwhk@ccu1.aukuni.ac.nz>
Subject: Re: Anyone can remove files
Date: 9 Oct 92 21:44:48 GMT
To:       info-unix@sem.brl.mil

coleman@bldrdoc.gov (Sean Coleman 497-5672 ) writes:

>If a directory has the permissions drwxrwxrwx and there
>exists a file in the directory owned by user A with
>permissions rw-------, why should anyone be allowed to
>remove the file?

You can prevent that in SGI's IRIX, and quite a nice feature it is, too:

[from the rm(1) manpage]

If the directory containing the file to be removed has the 'sticky' bit
set (see chmod(2)) then in order to remove the file one of the following
must be true:

	  the user owns	the file,
	  the user owns	the directory,
	  the file is writable by the user, or
	  the user is the super-user.
-- 
Thomas Koenig, ecmtwhk@ccu1.aukuni.ac.nz, ib09@rz.uni-karlsruhe.de
The joy of engineering is to find a straight line on a double logarithmic
diagram.

-----------------------------

From: Pat Chan <pchan@mdd.comm.mot.com>
Subject: Profiling on shared library..
Date: 8 Oct 92 23:35:15 GMT
To:       info-unix@sem.brl.mil

I'm trying to do profiling (Sun profile) on my program.
The ld chokes when it's a shared library.

Any help is welcome.

pat chan

-- 
Pat Chan                          Internet: pchan@mdd.comm.mot.com 
Motorola Mobile Data Division     Voice: (604) 241-6032
11411 Number Five Road            Fax: (604) 241-6042
Richmond, BC Canada V7A 4Z3

-----------------------------

From: Tim Thompson <tjt@blink.att.com>
Subject: Re: Profiling on shared library..
Date: 10 Oct 92 02:04:52 GMT
To:       info-unix@sem.brl.mil

barmar@think.com (Barry Margolin) writes:

>In article <tjt.718655662@sparc-10> tjt@blink.att.com (Tim Thompson) writes:
>>Can you use -Bstatic when compiling a program that uses -ldl ?

>No.  libdl.so.* is actually a dummy routine, and the dlopen(), et al ...
>However, it's possible to have a mixture of dynamic and static linking in a
>program, so you may be able to do this by only linking libdl dynamically.

I tried to do that (by putting -Bstatic and -Bdynamic at various points
in the command line) but never succeeded.  I'm suspecting that both
dynamic loading and profiling want to insert hooks into the startup
mechanism, and that those hooks can't co-exist.  Just a guess, though.

Inserting the profiling hooks manually would probably work.  If at some
point I get tired of hacking a staticly-linked version of my program, I'll
probably try that.     ...Tim...tjt@blink.att.com...

-----------------------------

From: Mike Digdon <digdon@ug.cs.dal.ca>
Subject: Sockets and stuff
Date: 9 Oct 92 02:46:00 GMT
To:       info-unix@sem.brl.mil


I am working on a project that involves a daemon, and obviously, I will be
using sockets for all of the communications. After looking thru various FAQ's
and stuff, I just can't seem to find what I am looking for..

I know how to set up a socket and talk with it.. however, my problem is
waiting for a connection and multiple users..

If a connection has not been made, I want my program (the daemon) to run
some other stuff, since more than one user will be able to access it at
a time. I am led to believe that accept sits and waits for a connection
of some sort and doesn't do anything else until a connection is made.
Am I incorrect in this assumption? If this is the case, how would I check
to see if a connection is being made, and if not, continue running other
parts of my program to take care of the users who are already connected.

And where might I find some stuff on the net that talks about sockets and
daemons and the like? I have a few books here, but they don't say much..
at least not what I need..
-- 
	     Mike Digdon - Vice Prez DSCSS - Dalhousie University
		     digdon@ug.cs.dal.ca  -- Halifax, NS
		 - Real programmers never work nine to five -

-----------------------------

From: Brad Bobak <bbobak@undergrad.math.uwaterloo.ca>
Subject: Re: Sockets and stuff
Date: 9 Oct 92 12:55:11 GMT
To:       info-unix@sem.brl.mil

In article <Bvu2Cp.69J@cs.dal.ca> you write:
>
>I am working on a project that involves a daemon, and obviously, I will be
>using sockets for all of the communications. After looking thru various FAQ's
>and stuff, I just can't seem to find what I am looking for..
>
>I know how to set up a socket and talk with it.. however, my problem is
>waiting for a connection and multiple users..
>
>If a connection has not been made, I want my program (the daemon) to run
>some other stuff, since more than one user will be able to access it at
>a time. I am led to believe that accept sits and waits for a connection
>of some sort and doesn't do anything else until a connection is made.
>Am I incorrect in this assumption?
 More or less, yes. (see below)

>If this is the case, how would I check
>to see if a connection is being made, and if not, continue running other
>parts of my program to take care of the users who are already connected.
 If you have the select() call on your system, you can use that. eg:

 fd_set fds;
 struct timeval tv;

 tv.tv_sec = 1;   /* spend max. 1 second checking for new connections */
 tv.tv_usec = 0;

 FD_ZERO(&fds);
 FD_SET(your_socket, &fds);

 /* actually, if your only checking your socket, you can set MAXFDS to
  * your sockets descriptor number + 1
  */
 select(MAXFDS/*NOFILE in /sys/param.h*/, &fds, (fd_set *)0, (fd_set *)0, &tv);
 /* don't forget to do error checking for select */
 if (FD_ISSET(your_socked, &fds))
 {
	/* something is ready on the socket */
	accept(...);
 }
 else
 {
	/* do your stuff */
 }

 if you don't have select, or want to do this another way:

 make your socket non-blocking, one way is to use O_NDELAY:

 fcntl(your_socket, F_SETFL, O_NDELAY);
 /* error checking.. */

 then do an accept:

 res = accept(...);
 if (res == -1  &&  errno == EWOULDBLOCK)
 {
	/* no new connection */
 }

>
>And where might I find some stuff on the net that talks about sockets and
>daemons and the like? I have a few books here, but they don't say much..
>at least not what I need..

  Use archie to find '07.ipctut' and '08.ipc' they're mainly just
 examples on how to do interprocess communication, but they'll more
 than likely help you out.
	
>-- 
>	     Mike Digdon - Vice Prez DSCSS - Dalhousie University
>		     digdon@ug.cs.dal.ca  -- Halifax, NS
>		 - Real programmers never work nine to five -

-----------------------------

From: "Georg S. Nikodym" <georgn@noweh.com>
Subject: Re: Solbourne blues, in Boot minor
Keywords: boot solbourne
Date: 9 Oct 92 04:39:59 GMT
To:       info-unix@sem.brl.mil

In article <2890@nlsun1.oracle.nl> rlyle@nl.oracle.com (The Wizard of Ozje - Garf) writes:
>Folks,
>
>I have inadvertently inserted an error in the bsh /etc/rc.boot script on my
>Solbourne portable Sun (Sparc inside).  Anybody any ideas about how I can fix
>the error short of reinstalling the whole thing again?  It boots into a bsh with
># prompt ofcourse, but there's nothing mounted so I can't run anything.  All the other rc scripts fall flat on their faces.  The root FS is mounted read-only,
>so I can't just stomp over it with echo in the shell.

Try booting with a "boot -s" command.  This will boot in single user and
hopefully not run any of the rc.* scripts.

Hope that helps...

-- 
Georg S. Nikodym  -  (416) 272-5198 / 720-4729
Noweh Software - Mississauga, Ontario, CANADA
UUCP:	{comspec.com, lsuc.on.ca, uunet.ca}!noweh!georgn
RFC822:	georgn@noweh.COM

-----------------------------

From: "Georg S. Nikodym" <georgn@noweh.com>
Subject: Re: comminicating with devices
Date: 9 Oct 92 04:53:22 GMT
To:       info-unix@sem.brl.mil

In article <1992Oct4.055849.7226@menudo.uh.edu> cavers@menudo.uh.edu (Chris M. Cavers) writes:
>I would like to get some hints on what is the best way to
>communicate with a device driver.

Open it ;-)

>Specifically, I have written a disk device driver.
>I would like to have a user level process communicate with
>the device and the device with the user level process.
>I would like to use message queues but am unsure of the effects
>of crossing the kernel/user boundary.  The main concern is 
>that the device should wake up whenever a message arrives and the message
>handling should not interfere with the normal device operations of
>the disk device driver...

It might be helpful to know what you want to do and why, since the way
you've presented your question makes me say, "Huh?!?"

Anyway, you should be aware that message queues are an IPC (Inter-Process
Communication) service provided by the kernel for user-level processes.
In short, this probably isn't what you want.

One way to achieve process to driver communication is via the ioctl(2)
mechanism.  Ie, you add support for various ioctl() calls to your driver
that would perform some useful function.

There isn't really any way for a driver to signal user level processes if
nobody's paying attention.

Another option might be to implement your driver as a STREAMS driver
(which probably isn't a good idea in the case of disks) and then you
might be able to create a STREAMS module that could effect the stuff
you want.

Sorry I can't be more complete, but lacking a good definition of your
problem/needs all I can do is supply information based on my assumptions
of your goals.

-- 
Georg S. Nikodym  -  (416) 272-5198 / 720-4729
Noweh Software - Mississauga, Ontario, CANADA
UUCP:	{comspec.com, lsuc.on.ca, uunet.ca}!noweh!georgn
RFC822:	georgn@noweh.COM

-----------------------------

From: Ted Timar <tmatimar@sunee.uwaterloo.ca>
Subject: Welcome to comp.unix.questions [Monthly posting]
Date: 9 Oct 92 05:00:57 GMT
Expires: Fri, 6 Nov 1992 05:00:14 GMT
Followup-To: comp.unix.questions
Supersedes: <unix-faq/unix-intro_717397221@athena.mit.edu>
X-Last-Updated: 1992/09/24
To:       info-unix@sem.brl.mil

Archive-name: unix-faq/unix-intro
Version: $Id: unix-intro,v 1.6 92/09/11 09:16:40 tmatimar Exp $

Comp.unix.questions is one of the most popular and highest volume
newsgroups on Usenet.  This article is a monthly attempt to remind
potential posters about what is appropriate for this newsgroup.
If you would like to make any suggestions about the content of
this article, please contact its maintainer at
tmatimar@sunee.uwaterloo.ca.

Companion articles include the answers to some Frequently
Asked Questions.  You may save yourself a lot of time by reading
those articles before posting a question to the net.

If you have not already read the overall Usenet introductory material
posted to "news.announce.newusers", please do.  Much of this article
overlaps with the common sense guidelines posted there.

	     Should I Post My Unix Question to the Net?

Often the answer is "No, you can get an answer a lot faster without
posting a question." Before you post, you should try -

    o Reading the manual for your system.  Some day you may encounter
      the phrase "RTFM", which stands for "Read the Fine Manual"
      (except 'F' doesn't really stand for "Fine").  If you ask
      someone a question and they tell you to RTFM, it's an
      indication that you haven't done your homework.   For instance,
      if you are having trouble removing a file whose name begins
      with a "-", check the man page for "rm".  It might tell
      you what you need to know.

      When people use terminology like "read(2)", they are referring
      to the "read" man page in section 2 of the manual (which you
      would see by using "man 2 read").

    o Finding a knowledgeable user at your site.  Many sites have
      at least a few Unix experts who will be happy to help you
      figure out how to remove a file whose name begins with "-".
      Many larger sites, particularly universities, may even have
      paid consultants whose job is to help you with Unix problems.
      Check with them first.

    o Find a good introductory book on Unix.  There are plenty of
      such books available, and you will save yourself a lot
      of trouble by having one handy and consulting it frequently.
      (Question 1.5 in the companion articles will let you know
       where you can find a list of good Unix and C books.)

Please remember that the comp.unix.* newsgroups are read by over 80,000
people around the world, and that posting a question to this group will
cost a lot of time and money by the time your article is distributed to
Asia, Australia, Europe (west and east), Africa, the middle east,
and all corners of North, South and Central America.

Also, some people receive these newsgroups as part of a mailing list
rather than a newsgroup.  If you're one of these people, please don't
send a "Remove me from this list" or "UNSUBSCRIBE"  message to the
wrong place.  Take the time to figure out where you're getting this
stuff from, and send your request to the mailing list maintainer, *not*
to the list or newsgroup itself!  Ask your local postmaster for help.
(One of the answers in the companion articles deals with the details of
the mailing list.)

               To Which Newsgroup Should I Post My Question?

The choice of newsgroup is harder than it used to be.  In the old days,
you just had to choose between "comp.unix.questions" and
"comp.unix.wizards".  Now there are a variety of more specific groups.
Choose one of the following groups carefully.  If you aren't sure where
your question belongs or if your question is not specific to some
particular version of Unix, try "comp.unix.questions".  Many
knowledgeable Unix wizards read that group and will be able to help you.

Here are the capsule descriptions of various groups you might consider
(extracted from a monthly posting to "news.announce.newusers")

comp.unix.questions     General questions from UNIX users and sys admins.
			If your question isn't a really good match for one of
			the groups below, post it here.

news.answers		Repository for periodic USENET articles. (Moderated)
			This article is crossposted there.
			Do not try to post here unless you're
			posting a list of FAQ's and their answers.

comp.unix.shell         Using and programming any UNIX shell.

comp.lang.c             Discussion about C.

comp.sources.unix       Postings of complete, UNIX-oriented sources. (Moderated)
comp.std.unix           Discussion for the P1003 committee on UNIX. (Moderated)
comp.unix               Discussion of UNIX* features and bugs. (Moderated)
comp.unix.admin         Administering a Unix-based system.
comp.unix.aix           IBM's version of UNIX.
comp.unix.amiga		Unix on the Commodore Amiga
comp.unix.aux           The version of UNIX for Apple Macintosh II computers.
comp.unix.bsd           Discussions relating to BSD UNIX.
comp.unix.internals     Discussions on hacking UNIX internals.
comp.unix.large         UNIX on mainframes and in large networks.
comp.unix.misc          Various topics that don't fit other groups.
comp.unix.msdos         MS-DOS running under UNIX by whatever means.
comp.unix.programmer    Q&A for people programming under Unix.
comp.unix.sysv286       UNIX System V (not XENIX) on the '286.
comp.unix.sysv386       Versions of Unix (not Xenix) on Intel 80386-based boxes.
comp.unix.ultrix        Discussions about DEC's Ultrix.
comp.unix.xenix.misc    General discussions regarding XENIX (except SCO).
comp.unix.xenix.sco     XENIX versions from the Santa Cruz Operation.

comp.unix.wizards       In-depth discussions of advanced unix topics.
			People should not post to this group unless they
			have used unix as a user, sysadmin and know details
			of the kernel, and how different unix kernels differ.
			In other words, don't post to comp.unix.wizards.

	      What Information Should I Include?

It's hard to include too much information.  There are hundreds of
different Unix systems out there, and they all have less in common
than you might think.  If you have a problem and are posting an
article, please be sure to mention:

    o A descriptive subject line.  Many people will decide whether
      to read your article solely on the basis of the subject line,
      so it should be a good statement of your problem.

      NOT GOOD                          GOOD

      "Help"                            "How do I sort a file by line length?"
      "Csh question"			"csh dumps core when I use '$<'"

    o What computer you are using, and what specific version
      of the operating system it uses.  For instance,

	    SunOS 4.0.1, Sun 3/50
	    4.3BSD-tahoe, Vax 11/780
	    SVR3.2, 3b2

    o If possible, the *exact* text of any error message you
      may have encountered.

      WRONG				RIGHT

      "I can't print this file"     "When I type 'lpr Filename', I get
				      lpr: Filename: File too ugly to print
				     What does this mean?  It isn't in
				     the man page.  This is using
				     Mueslix 9.3 on a Fax 68086502"

It's a good idea to post unrelated questions in separate articles,
so that people can keep different discussions separate.   It's also
a *very* good idea to include a line or two like this:

    "Please mail your answers to me and I'll summarize what I get
     and post the results to comp.unix.questions."

This prevents many identical responses from different users to the
same question from clogging up the newsgroup.  And make sure
you really summarize what you get - don't just concatenate
all the mail you've received.

It's also a good idea to read comp.unix.questions for at least a couple
of weeks after you post your article to see what followup articles
are posted.

                Should I Post an Answer to a Question?

It's very tempting to post an answer to a question you read on the net,
especially when you think "Aha, finally - a question I can answer!"
Consider though that when a simple question is asked, such as the
sort about to be answered below, many other people around the
world already know the answer and may be posting their own reply.
In order to avoid dozens of replies to simple questions, please
wait a day or so and see if anyone else has already answered
the question.  If you have something special to contribute, please
do so, but make sure you're not duplicating something someone else has
already done.

You should feel free to reply to any question >by email<.  Even if
the user gets 200 responses to his question, at least the load on the
rest of the net is minimized.

                    What About Posting Source Code?

Posting small amounts of example code is fine (use comp.sources.unix to
distribute complete programs) - but please make sure that your code
runs (or at least compiles) properly.  Don't just type it in while
editing your posting and hope it will work, no matter how sure you are
that it will.  We all make mistakes.

                        What About Those People
       Who Continue to Ask Stupid or Frequently Asked Questions
         In Spite of The Frequently Asked Questions Document?

Just send them a polite mail message, possibly referring them to this document.
There is no need to flame them on the net - it's busy enough as it is.
-- 
Ted Timar - tmatimar@sunee.uwaterloo.ca
Empress Software, 3100 Steeles Ave E, Markham, Ont., Canada L3R 8T3

-----------------------------

From: Ted Timar <tmatimar@sunee.uwaterloo.ca>
Subject: Frequently Asked Questions about Unix (index) [Monthly posting]
Date: 9 Oct 92 05:02:01 GMT
Expires: Fri, 6 Nov 1992 05:00:14 GMT
Followup-To: comp.unix.questions
Supersedes: <unix-faq/contents_717397221@athena.mit.edu>
X-Last-Updated: 1992/09/24
To:       info-unix@sem.brl.mil

Archive-name: unix-faq/contents
Version: $Id: contents,v 1.6 92/09/11 09:46:37 tmatimar Exp $

The following four articles contain the answers to some Frequently Asked
Questions often seen in comp.unix.questions and comp.unix.shell.
Please don't ask these questions again, they've been answered plenty
of times already - and please don't flame someone just because they may
not have read this particular posting.  Thank you.

These articles are divided approximately as follows:

      1.*) General questions.
      2.*) Relatively basic questions, likely to be asked by beginners.
      3.*) Intermediate questions.
      4.*) Advanced questions, likely to be asked by people who thought
	   they already knew all of the answers.

The following questions are answered:

      1.1)  Who helped you put this list together?
      1.2)  When someone refers to 'rn(1)' or 'ctime(3)', what does
              the number in parentheses mean?
      1.3)  What does {some strange unix command name} stand for?
      1.4)  How does the gateway between "comp.unix.questions" and the
              "info-unix" mailing list work?
      1.5)  What are some useful Unix or C books?
      1.6)  What happened to the pronunciation list that used to be
              part of this document?

      2.1)  How do I remove a file whose name begins with a "-" ?
      2.2)  How do I remove a file with funny characters in the filename ?
      2.3)  How do I get a recursive directory listing?
      2.4)  How do I get the current directory into my prompt?
      2.5)  How do I read characters from the terminal in a shell script?
      2.6)  How do I rename "*.foo" to "*.bar", or change file names
              to lowercase?
      2.7)  Why do I get [some strange error message] when I
              "rsh host command" ?
      2.8)  How do I {set an environment variable, change directory} inside a
              program or shell script and have that change affect my
              current shell?
      2.9)  How do I redirect stdout and stderr separately in csh?
      2.10) How do I tell inside .cshrc if I'm a login shell?
      2.11) How do I construct a shell glob-pattern that matches all files
            except "." and ".." ?
      2.12) How do I find the last argument in a Bourne shell script?
      2.13) What's wrong with having '.' in your $PATH ?

      3.1)  How do I find out the creation time of a file?
      3.2)  How do I use "rsh" without having the rsh hang around
              until the remote command has completed?
      3.3)  How do I truncate a file?
      3.4)  Why doesn't find's "{}" symbol do what I want?
      3.5)  How do I set the permissions on a symbolic link?
      3.6)  How do I "undelete" a file?
      3.7)  How can a process detect if it's running in the background?
      3.8)  Why doesn't redirecting a loop work as intended?  (Bourne shell)
      3.9)  How do I run 'passwd', 'ftp', 'telnet', 'tip' and other interactive
              programs from a shell script or in the background?
      3.10) How do I find out the process ID of a program with a particular
            name from inside a shell script or C program?
      3.11) How do I check the exit status of a remote command
            executed via "rsh" ?
      3.12) Is it possible to pass shell variable settings into an awk program?
      3.13) How do I get rid of zombie processes that persevere?
      3.14) How do I get lines from a pipe as they are written instead of
            only in larger blocks.

      4.1)  How do I read characters from a terminal without requiring the user
              to hit RETURN?
      4.2)  How do I check to see if there are characters to be read without
              actually reading?
      4.3)  How do I find the name of an open file?
      4.4)  How can an executing program determine its own pathname?
      4.5)  How do I use popen() to open a process for reading AND writing?
      4.6)  How do I sleep() in a C program for less than one second?
      4.7)  How can I get setuid shell scripts to work?
      4.8)  How can I find out which user or process has a file open or is using
            a particular file system (so that I can unmount it?)
      4.9)  How do I keep track of people who are fingering me?
      4.10) Is it possible to reconnect a process to a terminal after it has
            been disconnected, e.g. after starting a program in the background
            and logging out?
      4.11) Is it possible to "spy" on a terminal, displaying the output
            that's appearing on it on another terminal?

      If you're looking for the answer to, say, question 1.5, look in
      part 1 and search for the regular expression "^1.5)".

While these are all legitimate questions, they seem to crop up in
comp.unix.questions on an annual basis, usually followed by plenty
of replies (only some of which are correct) and then a period of
griping about how the same questions keep coming up.  You may also like
to read the monthly article "Answers to Frequently Asked Questions"
in the newsgroup "news.announce.newusers", which will tell you what
"UNIX" stands for.

With the variety of Unix systems in the world, it's hard to guarantee
that these answers will work everywhere.  Read your local manual pages
before trying anything suggested here.  If you have suggestions or
corrections for any of these answers, please send them to to
tmatimar@sunee.uwaterloo.ca.

-----------------------------

From: Ted Timar <tmatimar@sunee.uwaterloo.ca>
Subject: Frequently Asked Questions about Unix (1/4) [Monthly posting]
Date: 9 Oct 92 05:02:32 GMT
Expires: Fri, 6 Nov 1992 05:00:14 GMT
Followup-To: comp.unix.questions
Supersedes: <unix-faq/part1_717397221@athena.mit.edu>
X-Last-Updated: 1992/09/24
To:       info-unix@sem.brl.mil

Archive-name: unix-faq/part1
Version: $Id: part1,v 1.6 92/09/11 09:40:39 tmatimar Exp $

These four articles contain the answers to some Frequently Asked
Questions often seen in comp.unix.questions and comp.unix.shell.
Please don't ask these questions again, they've been answered plenty
of times already - and please don't flame someone just because they may
not have read this particular posting.  Thank you.

These articles are divided approximately as follows:

      1.*) General questions.
      2.*) Relatively basic questions, likely to be asked by beginners.
      3.*) Intermediate questions.
      4.*) Advanced questions, likely to be asked by people who thought
	   they already knew all of the answers.

This article includes answers to:

      1.1)  Who helped you put this list together?
      1.2)  When someone refers to 'rn(1)' or 'ctime(3)', what does
              the number in parentheses mean?
      1.3)  What does {some strange unix command name} stand for?
      1.4)  How does the gateway between "comp.unix.questions" and the
              "info-unix" mailing list work?
      1.5)  What are some useful Unix or C books?
      1.6)  What happened to the pronunciation list that used to be
              part of this document?

      If you're looking for the answer to, say, question 1.5, and want to skip
      everything else, you can search ahead for the regular expression "^1.5)".

While these are all legitimate questions, they seem to crop up in
comp.unix.questions on an annual basis, usually followed by plenty
of replies (only some of which are correct) and then a period of
griping about how the same questions keep coming up.  You may also like
to read the monthly article "Answers to Frequently Asked Questions"
in the newsgroup "news.announce.newusers", which will tell you what
"UNIX" stands for.

With the variety of Unix systems in the world, it's hard to guarantee
that these answers will work everywhere.  Read your local manual pages
before trying anything suggested here.  If you have suggestions or
corrections for any of these answers, please send them to to
tmatimar@sunee.uwaterloo.ca.

1.1)  Who helped you put this list together?

      I took over the maintenance of this list.  Almost all of the work
      (and the credit) for generating this compilation was done by
      Steve Hayman.

      We also owe a great deal of thanks to dozens of Usenet readers who
      submitted questions, answers, corrections and suggestions for this
      list.  Special thanks go to Maarten Litmaath, Guy Harris and
      Jonathan Kamens, who have all made many especially valuable
      contributions.

1.2)  When someone refers to 'rn(1)' or 'ctime(3)', what does
      the number in parentheses mean?

      It looks like some sort of function call, but it isn't.  These
      numbers refer to the section of the "Unix manual" where the
      appropriate documentation can be found.  You could type "man 3
      ctime" to look up the manual page for "ctime" in section 3 of
      the manual.

      The traditional manual sections are:

	1	User-level  commands
	2	System calls
	3	Library functions
	4	Devices and device drivers
	5	File formats
	6	Games
	7	Various miscellaneous stuff - macro packages etc.
	8	System maintenance and operation commands

      Some Unix versions use non-numeric section names.  For instance,
      Xenix uses "C" for commands and "S" for functions.

      Each section has an introduction, which you can read with "man #
      intro" where # is the section number.

      Sometimes the number is necessary to differentiate between a
      command and a library routine or system call of the same name.
      For instance, your system may have "time(1)", a manual page about
      the 'time' command for timing programs, and also "time(3)", a
      manual page about the 'time' subroutine for determining the
      current time.  You can use "man 1 time" or "man 3 time" to
      specify which "time" man page you're interested in.

      You'll often find other sections for local programs or even
      subsections of the sections above - Ultrix has sections 3m, 3n,
      3x and 3yp among others.

1.3)  What does {some strange unix command name} stand for?

      awk = "Aho Weinberger and Kernighan"

	This language was named by its authors, Al Aho, Peter
	Weinberger and Brian Kernighan.

      grep = "Global Regular Expression Print"

	grep comes from the ed command to print all lines matching a
	certain pattern

		    g/re/p

	where "re" is a "regular expression".

      fgrep = "Fixed GREP".

	fgrep searches for fixed strings only.  The "f" does not stand
	for "fast" - in fact, "fgrep foobar *.c" is usually slower than
	"egrep foobar *.c"  (Yes, this is kind of surprising. Try it.)

	Fgrep still has its uses though, and may be useful when searching
	a file for a larger number of strings than egrep can handle.

      egrep = "Extended GREP"

	egrep uses fancier regular expressions than grep.  Many people
	use egrep all the time, since it has some more sophisticated
	internal algorithms than grep or fgrep, and is usually the
	fastest of the three programs.

      cat = "CATenate"

	catenate is an obscure word meaning "to connect in a series",
	which is what the "cat" command does to one or more files.  Not
	to be confused with C/A/T, the Computer Aided Typesetter.

      gecos = "General Electric Comprehensive Operating System"
	
	When GE's large systems division was sold to Honeywell,
	Honeywell dropped the "E" from "GECOS".

	Unix's password file has a "pw_gecos" field.  The name is a
	real holdover from the early days.  Dennis Ritchie has reported:

	    "Sometimes we sent printer output or batch jobs
	     to the GCOS machine.  The gcos field in the password file
	     was a place to stash the information for the $IDENT card.
	     Not elegant."

      nroff = "New ROFF"
      troff = "Typesetter new ROFF"
	
	These are descendants of "roff", which was a re-implementation
	of the Multics "runoff" program (a program that you'd use to
	"run off" a good copy of a document).

      tee       = T

	From plumbing terminology for a T-shaped pipe splitter.

      bss = "Block Started by Symbol"
	
	Dennis Ritchie says:

	    Actually the acronym (in the sense we took it up; it may
	    have other credible etymologies) is "Block Started by
	    Symbol." It was a pseudo-op in FAP (Fortran Assembly [-er?]
	    Program), an assembler for the IBM 704-709-7090-7094
	    machines.  It defined its label and set aside space for a
	    given number of words.  There was another pseudo-op, BES,
	    "Block Ended by Symbol" that did the same except that the
	    label was defined by the last assigned word + 1.  (On these
	    machines Fortran arrays were stored backwards in storage
	    and were 1-origin.)

	    The usage is reasonably appropriate, because just as with
	    standard Unix loaders, the space assigned didn't have to be
	    punched literally into the object deck but was represented
	    by a count somewhere.

      biff = "BIFF"

	This command, which turns on asynchronous mail notification,
	was actually named after a dog at Berkeley.

	    I can confirm the origin of biff, if you're interested.
	    Biff was Heidi Stettner's dog, back when Heidi (and I, and
	    Bill Joy) were all grad students at U.C. Berkeley and the
	    early versions of BSD were being developed.   Biff was
	    popular among the residents of Evans Hall, and was known
	    for barking at the mailman, hence the name of the command.

	Confirmation courtesy of Eric Cooper, Carnegie Mellon University

      rc (as in ".cshrc" or "/etc/rc") = "RunCom"

	"rc" derives from "runcom", from the MIT CTSS system, ca. 1965.

	    'There was a facility that would execute a bunch of
	    commands stored in a file; it was called "runcom" for "run
	    commands", and the file began to be called "a runcom."

	    "rc" in Unix is a fossil from that usage.'
	
	Brian Kernighan & Dennis Ritchie, as told to Vicki Brown

	"rc" is also the name of the shell from the new Plan 9
	operating system.

      Perl = "Practical Extraction and Report Language"

	The Perl language is Larry Wall's highly popular
	freely-available completely portable text, process, and file
	manipulation tool that bridges the gap between shell and C
	programming (or between doing it on the command line and
	pulling your hair out).  For further information, see the
	Usenet newsgroup comp.lang.perl.

      Don Libes' book "Life with Unix" contains lots more of these
      tidbits.

1.4)  How does the gateway between "comp.unix.questions" and the
      "info-unix" mailing list work?

      "Info-Unix" and "Unix-Wizards" are mailing list versions of
      comp.unix.questions and comp.unix.wizards respectively.
      There should be no difference in content between the
      mailing list and the newsgroup.

      To get on or off either of these lists, send mail to
      Info-Unix-Request@brl.mil or Unix-Wizards-Request@brl.mil .
      Be sure to use the '-Request'.  Don't expect an immediate response.

      Here are the gory details, courtesy of the list's maintainer,
      Bob Reschly.

      ==== postings to info-UNIX and UNIX-wizards lists ====

      Anything submitted to the list is posted; I do not moderate
      incoming traffic -- BRL functions as a reflector.  Postings
      submitted by Internet subscribers should be addressed to the list
      address (info-UNIX or UNIX- wizards);  the '-request' addresses
      are for correspondence with the list maintainer [me].  Postings
      submitted by USENET readers should be addressed to the
      appropriate news group (comp.unix.questions or
      comp.unix.wizards).

      For Internet subscribers, received traffic will be of two types;
      individual messages, and digests.  Traffic which comes to BRL
      from the Internet and BITNET (via the BITNET-Internet gateway) is
      immediately resent to all addressees on the mailing list.
      Traffic originating on USENET is gathered up into digests which
      are sent to all list members daily.

      BITNET traffic is much like Internet traffic.  The main
      difference is that I maintain only one address for traffic
      destined to all BITNET subscribers. That address points to a list
      exploder which then sends copies to individual BITNET
      subscribers.  This way only one copy of a given message has to
      cross the BITNET-Internet gateway in either direction.

      USENET subscribers see only individual messages.  All messages
      originating on the Internet side are forwarded to our USENET
      machine.  They are then posted to the appropriate newsgroup.
      Unfortunately, for gatewayed messages, the sender becomes
      "news@brl-adm".  This is currently an unavoidable side-effect of
      the software which performs the gateway function.

      As for readership, USENET has an extremely large readership - I
      would guess several thousand hosts and tens of thousands of
      readers.  The master list maintained here at BRL runs about two
      hundred fifty entries with roughly ten percent of those being
      local redistribution lists.  I don't have a good feel for the
      size of the BITNET redistribution, but I would guess it is
      roughly the same size and composition as the master list.
      Traffic runs 150K to 400K bytes per list per week on average.

1.5)  What are some useful Unix or C books?

      Mitch Wright (mitch@cirrus.com) maintains a useful list of Unix
      and C books, with descriptions and some mini-reviews.  There are
      currently 77 titles on his list.

      You can obtain a copy of this list by anonymous ftp from
      ftp.wg.omron.co.jp (133.210.4.4), where it's
      "pub/unix-faq/Unix-C-Booklist".  If you can't use anonymous ftp,
      email the line "help" to "mailserv@iuvax.cs.indiana.edu" for
      instructions on retrieving things via email.

      Send additions or suggestions to mitch@cirrus.com.

1.6)  What happened to the pronunciation list that used to be part of this
      document?

      From its inception in 1989, this FAQ document included a
      comprehensive pronunciation list maintained by Maarten Litmaath
      (thanks, Maarten!).  (Does anyone know who *created* it?)

      It has been retired, since it is not really relevant to the topic
      of "Unix questions".  You can still find it as part of the
      widely-distributed "Jargon" file (maintained by Eric S. Raymond,
      eric@snark.thyrsus.com) which seems like a much more appropriate
      forum for the topic of "How do you pronounce  /* ?"

      If you'd like a copy, you can ftp one from ftp.wg.omron.co.jp
      (133.210.4.4), it's "pub/unix-faq/Pronunciation-Guide".

-- 
Ted Timar - tmatimar@sunee.uwaterloo.ca
Empress Software, 3100 Steeles Ave E, Markham, Ont., Canada L3R 8T3

-----------------------------

From: Ted Timar <tmatimar@sunee.uwaterloo.ca>
Subject: Frequently Asked Questions about Unix (2/4) [Monthly posting]
Date: 9 Oct 92 05:02:55 GMT
Expires: Fri, 6 Nov 1992 05:00:14 GMT
Followup-To: comp.unix.questions
Supersedes: <unix-faq/part2_717397221@athena.mit.edu>
X-Last-Updated: 1992/09/24
To:       info-unix@sem.brl.mil

Archive-name: unix-faq/part2
Version: $Id: part2,v 1.6 92/09/11 09:15:29 tmatimar Exp $

These four articles contain the answers to some Frequently Asked
Questions often seen in comp.unix.questions and comp.unix.shell.
Please don't ask these questions again, they've been answered plenty
of times already - and please don't flame someone just because they may
not have read this particular posting.  Thank you.

These articles are divided approximately as follows:

      1.*) General questions.
      2.*) Relatively basic questions, likely to be asked by beginners.
      3.*) Intermediate questions.
      4.*) Advanced questions, likely to be asked by people who thought
	   they already knew all of the answers.

This article includes answers to:

      2.1)  How do I remove a file whose name begins with a "-" ?
      2.2)  How do I remove a file with funny characters in the filename ?
      2.3)  How do I get a recursive directory listing?
      2.4)  How do I get the current directory into my prompt?
      2.5)  How do I read characters from the terminal in a shell script?
      2.6)  How do I rename "*.foo" to "*.bar", or change file names
              to lowercase?
      2.7)  Why do I get [some strange error message] when I
              "rsh host command" ?
      2.8)  How do I {set an environment variable, change directory} inside a
              program or shell script and have that change affect my
              current shell?
      2.9)  How do I redirect stdout and stderr separately in csh?
      2.10) How do I tell inside .cshrc if I'm a login shell?
      2.11) How do I construct a shell glob-pattern that matches all files
            except "." and ".." ?
      2.12) How do I find the last argument in a Bourne shell script?
      2.13) What's wrong with having '.' in your $PATH ?

    If you're looking for the answer to, say, question 2.5, and want to skip
    everything else, you can search ahead for the regular expression "^2.5)".

While these are all legitimate questions, they seem to crop up in
comp.unix.questions on an annual basis, usually followed by plenty
of replies (only some of which are correct) and then a period of
griping about how the same questions keep coming up.  You may also like
to read the monthly article "Answers to Frequently Asked Questions"
in the newsgroup "news.announce.newusers", which will tell you what
"UNIX" stands for.

With the variety of Unix systems in the world, it's hard to guarantee
that these answers will work everywhere.  Read your local manual pages
before trying anything suggested here.  If you have suggestions or
corrections for any of these answers, please send them to to
tmatimar@sunee.uwaterloo.ca.

2.1)  How do I remove a file whose name begins with a "-" ?

      Figure out some way to name the file so that it doesn't begin
      with a dash.  The simplest answer is to use

	    rm ./-filename

      (assuming "-filename" is in the current directory, of course.)
      This method of avoiding the interpretation of the "-" works with
      other commands too.

      Many commands, particularly those that have been written to use
      the "getopt(3)" argument parsing routine, accept a "--" argument
      which means "this is the last option, anything after this is not
      an option", so your version of rm might handle "rm -- -filename".
      Some versions of rm that don't use getopt() treat a single "-"
      in the same way, so you can also try "rm - -filename".

2.2)  How do I remove a file with funny characters in the filename ?

      If the 'funny character' is a '/', skip to the last part of this
      answer.  If the funny character is something else, such as a ' '
      or control character or character with the 8th bit set, keep reading.

      The classic answers are

	rm -i some*pattern*that*matches*only*the*file*you*want

	which asks you whether you want to remove each file matching
	the indicated pattern;  depending on your shell, this may not
	work if the filename has a character with the 8th bit set (the
	shell may strip that off);

      and

	rm -ri .

	which asks you whether to remove each file in the directory.
	Answer "y" to the problem file and "n" to everything else.
	Unfortunately this doesn't work with many versions of rm.  Also
	unfortunately, this will walk through every subdirectory of ".",
	so you might want to "chmod a-x" those directories temporarily
	to make them unsearchable.

	Always take a deep breath and think about what you're doing and
	double check what you typed when you use rm's "-r" flag or a
	wildcard on the command line;

      and

	find . -type f ... -ok rm '{}' \;

      where "..." is a group of predicates that uniquely identify the
      file.  One possibility is to figure out the inode number of the
      problem file (use "ls -i .") and then use

	find . -inum 12345 -ok rm '{}' \;

      or
	find . -inum 12345 -ok mv '{}' new-file-name \;
	
      "-ok" is a safety check - it will prompt you for confirmation of
      the command it's about to execute.  You can use "-exec" instead
      to avoid the prompting, if you want to live dangerously, or if
      you suspect that the filename may contain a funny character
      sequence that will mess up your screen when printed.

      What if the filename has a '/' in it?

      These files really are special cases, and can only be created by
      buggy kernel code (typically by implementations of NFS that don't
      filter out illegal characters in file names from remote
      machines.)  The first thing to do is to try to understand exactly
      why this problem is so strange.

      Recall that Unix directories are simply pairs of filenames and
      inode numbers.  A directory essentially contains information
      like this:

	filename  inode

	file1	  12345
	file2.c	  12349
	file3     12347

      Theoretically, '/' and '\0' are the only two characters that
      cannot appear in a filename - '/' because it's used to separate
      directories and files, and '\0' because it terminates a filename.

      Unfortunately some implementations of NFS will blithely create
      filenames with embedded slashes in response to requests from
      remote machines.  For instance, this could happen when someone on
      a Mac or other non-Unix machine decides to create a remote NFS
      file on your Unix machine with the date in the filename.  Your
      Unix directory then has this in it:

	filename  inode

	91/02/07  12357

      No amount of messing around with 'find' or 'rm' as described
      above will delete this file, since those utilities and all other
      Unix programs, are forced to interpret the '/' in the normal way.

      Any ordinary program will eventually try to do
      unlink("91/02/07"), which as far as the kernel is concerned means
      "unlink the file 07 in the subdirectory 02 of directory 91", but
      that's not what we have - we have a *FILE* named "91/02/07" in
      the current directory.  This is a subtle but crucial distinction.

      What can you do in this case?  The first thing to try is to
      return to the Mac that created this crummy entry, and see if you
      can convince it and your local NFS daemon to rename the file to
      something without slashes.

      If that doesn't work or isn't possible, you'll need help from
      your system manager, who will have to try the one of the
      following.  Use "ls -i" to find the inode number of this bogus
      file, then unmount the file system and use "clri" to clear the
      inode, and "fsck" the file system with your fingers crossed.
      This destroys the information in the file.  If you want to keep
      it, you can try:

	create a new directory in the same parent directory as the one
	containing the bad file name;

	move everything you can (i.e. everything but the file with the
	bad name) from the old directory to the new one;

	do "ls -id" on the directory containing the file with the bad
	name to get its inumber;

	umount the file system;

	"clri" the directory containing the file with the bad name;

	"fsck" the file system.

      Then, to find the file,

	remount the file system;

	rename the directory you created to have the name of the old
	directory (since the old directory should have been blown away
	by "fsck")

	move the file out of "lost+found" into the directory with a
	better name.

      Alternatively, you can patch the directory the hard way by
      crawling around in the raw file system.  Use "fsdb", if you
      have it.

2.3)  How do I get a recursive directory listing?

      One of the following may do what you want:

	ls -R 			(not all versions of "ls" have -R)
	find . -print		(should work everywhere)
	du -a .			(shows you both the name and size)

      If you're looking for a wildcard pattern that will match all ".c"
      files in this directory and below, you won't find one, but you
      can use

	% some-command `find . -name '*.c' -print`

      "find" is a powerful program.  Learn about it.

2.4)  How do I get the current directory into my prompt?

      It depends which shell you are using.  It's easy with some
      shells, hard or impossible with others.

      C Shell (csh):
	Put this in your .cshrc - customize the prompt variable the
	way you want.

	    alias setprompt 'set prompt="${cwd}% "'
	    setprompt		# to set the initial prompt
	    alias cd 'chdir \!* && setprompt'
	
	If you use pushd and popd, you'll also need

	    alias pushd 'pushd \!* && setprompt'
	    alias popd  'popd  \!* && setprompt'

	Some C shells don't keep a $cwd variable - you can use
	`pwd` instead.

	If you just want the last component of the current directory
	in your prompt ("mail% " instead of "/usr/spool/mail% ")
	you can use

	    alias setprompt 'set prompt="$cwd:t% "'
	
	Some older csh's get the meaning of && and || reversed.
	Try doing:

	    false && echo bug

	If it prints "bug", you need to switch && and || (and get
	a better version of csh.)

      Bourne Shell (sh):

	If you have a newer version of the Bourne Shell (SVR2 or newer)
	you can use a shell function to make your own command, "xcd" say:

	    xcd() { cd $* ; PS1="`pwd` $ "; }

	If you have an older Bourne shell, it's complicated but not
	impossible.  Here's one way.  Add this to your .profile file:

		LOGIN_SHELL=$$ export LOGIN_SHELL
		CMDFILE=/tmp/cd.$$ export CMDFILE
		# 16 is SIGURG, pick a signal that's not likely to be used
		PROMPTSIG=16 export PROMPTSIG
		trap '. $CMDFILE' $PROMPTSIG

	and then put this executable script (without the indentation!),
	let's call it "xcd", somewhere in your PATH

		: xcd directory - change directory and set prompt
		: by signalling the login shell to read a command file
		cat >${CMDFILE?"not set"} <<EOF
		cd $1
		PS1="\`pwd\`$ "
		EOF
		kill -${PROMPTSIG?"not set"} ${LOGIN_SHELL?"not set"}

	Now change directories with "xcd /some/dir".

      Korn Shell (ksh):

	Put this in your .profile file:
		PS1='$PWD $ '
	
	If you just want the last component of the directory, use
		PS1='${PWD##*/} $ '

      T C shell (tcsh)

	Tcsh is a popular enhanced version of csh with some extra
	builtin variables (and many other features):

	    %~		the current directory, using ~ for $HOME
	    %d or %/	the full pathname of the current directory
	    %c or %.	the trailing component of the current directory

	so you can do

	    set prompt='%~ '

      BASH (FSF's "Bourne Again SHell")
	
	\w in $PS1 gives the full pathname of the current directory,
	with ~ expansion for $HOME;  \W gives the basename of
	the current directory.  So, in addition to the above sh and
	ksh solutions, you could use

	    PS1='\w $ '	
	or
	    PS1='\W $ '

2.5)  How do I read characters from the terminal in a shell script?

      In sh, use read.  It is most common to use a loop like

	    while read line
	    do
		    ...
	    done

      In csh, use $< like this:
	
	    while ( 1 )
		set line = "$<"
		if ( "$line" == "" ) break
		...
	    end

      Unfortunately csh has no way of distinguishing between a blank
      line and an end-of-file.

      If you're using sh and want to read a *single* character from the
      terminal, you can try something like

	    echo -n "Enter a character: "
	    stty cbreak		# or  stty raw
	    readchar=`dd if=/dev/tty bs=1 count=1 2>/dev/null`
	    stty -cbreak

	    echo "Thank you for typing a $readchar ."

2.6)  How do I rename "*.foo" to "*.bar", or change file names to lowercase?
	
      Why doesn't "mv *.foo *.bar" work?  Think about how the shell
      expands wildcards.   "*.foo" and "*.bar" are expanded before the
      mv command ever sees the arguments.  Depending on your shell,
      this can fail in a couple of ways.  CSH prints "No match."
      because it can't match "*.bar".  SH executes "mv a.foo b.foo
      c.foo *.bar", which will only succeed if you happen to have a
      single directory named "*.bar", which is very unlikely and almost
      certainly not what you had in mind.

      Depending on your shell, you can do it with a loop to "mv" each
      file individually.  If your system has "basename", you can use:

      C Shell:
	foreach f ( *.foo )
	    set base=`basename $f .foo`
	    mv $f $base.bar
	end

      Bourne Shell:
	for f in *.foo; do
	    base=`basename $f .foo`
	    mv $f $base.bar
	done

      Some shells have their own variable substitution features, so
      instead of using "basename", you can use simpler loops like:

      C Shell:

	foreach f ( *.foo )
	    mv $f $f:r.bar
	end

      Korn Shell:

	for f in *.foo; do
	    mv $f ${f%foo}bar
	done

      If you don't have "basename" or want to do something like
      renaming foo.* to bar.*, you can use something like "sed" to
      strip apart the original file name in other ways, but the general
      looping idea is the same.  You can also convert file names into
      "mv" commands with 'sed', and hand the commands off to "sh" for
      execution.  Try

	ls -d *.foo | sed -e 's/.*/mv & &/' -e 's/foo$/bar/' | sh

      A program by Vladimir Lanin called "mmv" that does this job
      nicely was posted to comp.sources.unix (Volume 21, issues 87 and
      88) in April 1990.  It lets you use

	mmv '*.foo' '=1.bar'

      Shell loops like the above can also be used to translate file
      names from upper to lower case or vice versa.  You could use
      something like this to rename uppercase files to lowercase:

	C Shell:
	    foreach f ( * )
		mv $f `echo $f | tr '[A-Z]' '[a-z]'`
	    end
	Bourne Shell:
	    for f in *; do
		mv $f `echo $f | tr '[A-Z]' '[a-z]'`
	    done
	Korn Shell:
	    typeset -l l
	    for f in *; do
		l="$f"
		mv $f $l
	    done

      If you wanted to be really thorough and handle files with `funny'
      names (embedded blanks or whatever) you'd need to use

	Bourne Shell:

	    for f in *; do
	      g=`expr "xxx$f" : 'xxx\(.*\)' | tr '[A-Z]' '[a-z]'`
	      mv "$f" "$g"
	    done

      The `expr' command will always print the filename, even if it
      equals `-n' or if it contains a System V escape sequence like `\c'.

      Some versions of "tr" require the [ and ], some don't.  It
      happens to be harmless to include them in this particular
      example; versions of tr that don't want the [] will conveniently
      think they are supposed to translate '[' to '[' and ']' to ']'.

      If you have the "perl" language installed, you may find this
      rename script by Larry Wall very useful.  It can be used to
      accomplish a wide variety of filename changes.

	#!/usr/bin/perl
	#
	# rename script examples from lwall:
	#       rename 's/\.orig$//' *.orig
	#       rename 'y/A-Z/a-z/ unless /^Make/' *
	#       rename '$_ .= ".bad"' *.f
	#       rename 'print "$_: "; s/foo/bar/ if <stdin> =~ /^y/i' *

	$op = shift;
	for (@ARGV) {
	    $was = $_;
	    eval $op;
	    die $@ if $@;
	    rename($was,$_) unless $was eq $_;
	}

2.7)  Why do I get [some strange error message] when I "rsh host command" ?

      (We're talking about the remote shell program "rsh" or sometimes
      "remsh" or "remote"; on some machines, there is a restricted shell
      called "rsh", which is a different thing.)

      If your remote account uses the C shell, the remote host will
      fire up a C shell to execute 'command' for you, and that shell
      will read your remote .cshrc file.  Perhaps your .cshrc contains
      a "stty", "biff" or some other command that isn't appropriate for
      a non-interactive shell.  The unexpected output or error message
      from these commands can screw up your rsh in odd ways.

      Here's an example.  Suppose you have

	stty erase ^H
	biff y

      in your .cshrc file.  You'll get some odd messages like this.

	% rsh some-machine date
	stty: : Can't assign requested address
	Where are you?
	Tue Oct  1 09:24:45 EST 1991

      You might also get similar errors when running certain "at" or
      "cron" jobs that also read your .cshrc file.

      Fortunately, the fix is simple.  There are, quite possibly, a
      whole *bunch* of operations in your ".cshrc" (e.g., "set
      history=N") that are simply not worth doing except in interactive
      shells.  What you do is surround them in your ".cshrc" with:

	    if ( $?prompt ) then
		    operations....
	    endif

      and, since in a non-interactive shell "prompt" won't be set, the
      operations in question will only be done in interactive shells.

      You may also wish to move some commands to your .login file; if
      those commands only need to be done when a login session starts
      up (checking for new mail, unread news and so on) it's better to
      have them in the .login file.

2.8)  How do I {set an environment variable, change directory} inside
      a program or shell script and have that change affect my
      current shell?

      In general, you can't, at least not without making special
      arrangements.  When a child process is created, it inherits a
      copy of its parent's variables (and current directory).  The
      child can change these values all it wants but the changes won't
      affect the parent shell, since the child is changing a copy of
      the original data.

      Some special arrangements are possible.  Your child process could
      write out the changed variables, if the parent was prepared to
      read the output and interpret it as commands to set its own
      variables.

      Also, shells can arrange to run other shell scripts in the
      context of the current shell, rather than in a child process, so
      that changes will affect the original shell.

      For instance, if you have a C shell script named "myscript":

	cd /very/long/path
	setenv PATH /something:/something-else

      or the equivalent Bourne or Korn shell script

	cd /very/long/path
	PATH=/something:/something-else export PATH

      and try to run "myscript" from your shell, your shell will fork
      and run the shell script in a subprocess.  The subprocess is also
      running the shell; when it sees the "cd" command it changes *its*
      current directory, and when it sees the "setenv" command it
      changes *its* environment, but neither has any effect on the
      current directory of the shell at which you're typing (your login
      shell, let's say).

      In order to get your login shell to execute the script (without
      forking) you have to use the "." command (for the Bourne or Korn
      shells) or the "source" command (for the C shell).  I.e. you type

	. myscript

      to the Bourne or Korn shells, or

	source myscript

      to the C shell.

      If all you are trying to do is change directory or set an
      environment variable, it will probably be simpler to use a C
      shell alias or Bourne/Korn shell function.  See the "how do I get
      the current directory into my prompt" section of this article for
      some examples.

2.9)  How do I redirect stdout and stderr separately in csh?

      In csh, you can redirect stdout with ">", or stdout and stderr
      together with ">&" but there is no direct way to redirect stderr
      only.  The best you can do is

	( command >stdout_file ) >&stderr_file

      which runs "command" in a subshell;  stdout is redirected inside
      the subshell to stdout_file, and both stdout and stderr from the
      subshell are redirected to stderr_file, but by this point stdout
      has already been redirected so only stderr actually winds up in
      stderr_file.

      Sometimes it's easier to let sh do the work for you.

	sh -c 'command >stdout_file 2>stderr_file'

2.10) How do I tell inside .cshrc if I'm a login shell?

      When people ask this, they usually mean either

	How can I tell if it's an interactive shell?  or
	How can I tell if it's a top-level shell?

      You could perhaps determine if your shell truly is a login shell
      (i.e. is going to source ".login" after it is done with ".cshrc")
      by fooling around with "ps" and "$$".  Login shells generally
      have names that begin with a '-'.  If you're really interested in
      the other two questions, here's one way you can organize your
      .cshrc to find out.

	if (! $?CSHLEVEL) then
		#
		# This is a "top-level" shell,
		# perhaps a login shell, perhaps a shell started up by
		# 'rsh machine some-command'
		# This is where we should set PATH and anything else we
		# want to apply to every one of our shells.
		#
		setenv      CSHLEVEL        0
		set home = ~username        # just to be sure
		source ~/.env               # environment stuff we always want
	else
		#
		# This shell is a child of one of our other shells so
		# we don't need to set all the environment variables again.
		#
		set tmp = $CSHLEVEL
		@ tmp++
		setenv      CSHLEVEL        $tmp
	endif

	# Exit from .cshrc if not interactive, e.g. under rsh
	if (! $?prompt) exit

	# Here we could set the prompt or aliases that would be useful
	# for interactive shells only.

	source ~/.aliases

2.11) How do I construct a shell glob-pattern that matches all files
      except "." and ".." ?

      You'd think this would be easy.

      *        Matches all files that don't begin with a ".";

      .*	     Matches all files that do begin with a ".", but
	     this includes the special entries "." and "..",
	     which often you don't want;

      .[!.]*   (Newer shells only; some shells use a "^" instead of
	     the "!"; POSIX shells must accept the "!", but may
	     accept a "^" as well; all portable applications shall
	     not use an unquoted "^" immediately following the "[")

	     Matches all files that begin with a "." and are
	     followed by a non-"."; unfortunately this will miss
	     "..foo";

      .??*     Matches files that begin with a "." and which are
	     at least 3 characters long.  This neatly avoids
	     "." and "..", but also misses ".a" .

      So to match all files except "." and ".." safely you have to use
      3 patterns (if you don't have filenames like ".a" you can leave
      out the first):

	.[!.]* .??* *

      Alternatively you could employ an external program or two and use
      backquote substitution.  This is pretty good:

      `ls -a | sed -e '/^\.$/d' -e '/^\.\.$/d'`

	(or `ls -A` in some Unix versions)

      but even it will mess up on files with newlines, IFS characters
      or wildcards in their names.

2.12) How do I find the last argument in a Bourne shell script?

      Answer by:
	Martin Weitzel <@mikros.systemware.de:martin@mwtech.uucp>
	Maarten Litmaath <maart@nat.vu.nl>

      If you are sure the number of arguments is at most 9, you can use:

	eval last=\${$#}

      In POSIX-compatible shells it works for ANY number of arguments.
      The following works always too:

	for last
	do
		:
	done

      This can be generalized as follows:

	for i
	do
		third_last=$second_last
		second_last=$last
		last=$i
	done

      Now suppose you want to REMOVE the last argument from the list,
      or REVERSE the argument list, or ACCESS the N-th argument
      directly, whatever N may be.  Here is a basis of how to do it,
      using only built-in shell constructs, without creating subprocesses:

	t0= u0= rest='1 2 3 4 5 6 7 8 9' argv=

	for h in '' $rest
	do
		for t in "$t0" $rest
		do
			for u in $u0 $rest
			do
				case $# in
				0)
					break 3
				esac
				eval argv$h$t$u=\$1
				argv="$argv \"\$argv$h$t$u\""	# (1)
				shift
			done
			u0=0
		done
		t0=0
	done

	# now restore the arguments
	eval set x "$argv"					# (2)
	shift

      This example works for the first 999 arguments.  Enough?
      Take a good look at the lines marked (1) and (2) and convince
      yourself that the original arguments are restored indeed, no
      matter what funny characters they contain!

      To find the N-th argument now you can use this:

	eval argN=\$argv$N

      To reverse the arguments the line marked (1) must be changed to:

	argv="\"\$argv$h$t$u\" $argv"

      How to remove the last argument is left as an exercise.

      If you allow subprocesses as well, possibly executing nonbuilt-in
      commands, the `argvN' variables can be set up more easily:

	N=1

	for i
	do
		eval argv$N=\$i
		N=`expr $N + 1`
	done

      To reverse the arguments there is still a simpler method, that
      even does not create subprocesses.  This approach can also be
      taken if you want to delete e.g. the last argument, but in that
      case you cannot refer directly to the N-th argument any more,
      because the `argvN' variables are set up in reverse order:

	argv=

	for i
	do
		eval argv$#=\$i
		argv="\"\$argv$#\" $argv"
		shift
	done

	eval set x "$argv"
	shift

2.13) What's wrong with having '.' in your $PATH ?

      A bit of background: the PATH environment variable is a list of
      directories separated by colons.  When you type a command name
      without giving an explicit path (e.g. you type "ls", rather than
      "/bin/ls") your shell searches each directory in the PATH list in
      order, looking for an executable file by that name, and the shell
      will run the first matching program it finds.

      One of the directories in the PATH list can be the current
      directory "." .  It is also permissible to use an empty directory
      name in the PATH list to indicate the current directory.  Both of
      these are equivalent

      for csh users:

	setenv PATH :/usr/ucb:/bin:/usr/bin
	setenv PATH .:/usr/ucb:/bin:/usr/bin

      for sh or ksh users

	PATH=:/usr/ucb:/bin:/usr/bin export PATH
	PATH=.:/usr/ucb:/bin:/usr/bin export PATH

      Having "." somewhere in the PATH is convenient - you can type
      "a.out" instead of "./a.out" to run programs in the current
      directory.  But there's a catch.

      Consider what happens in the case  where "." is the first entry
      in the PATH.  Suppose your current directory is a publically-
      writable one, such as "/tmp".  If there just happens to be a
      program named "/tmp/ls" left there by some other user, and you
      type "ls" (intending, of course, to run the normal "/bin/ls"
      program), your shell will instead run "./ls", the other user's
      program.  Needless to say, the results of running an unknown
      program like this might surprise you.

      It's slightly better to have "." at the end of the PATH:

	setenv PATH /usr/ucb:/bin:/usr/bin:.

      Now if you're in /tmp and you type "ls", the shell will
      search /usr/ucb, /bin and /usr/bin for a program named
      "ls" before it gets around to looking in ".", and there
      is less risk of inadvertently running some other user's
      "ls" program.  This isn't 100% secure though - if you're
      a clumsy typist and some day type "sl -l" instead of "ls -l",
      you run the risk of running "./sl", if there is one.
      Some "clever" programmer could anticipate common typing
      mistakes and leave programs by those names scattered
      throughout public directories.  Beware.

      Many seasoned Unix users get by just fine without having
      "." in the PATH at all:

	setenv PATH /usr/ucb:/bin:/usr/bin

      If you do this, you'll need to type "./program" instead
      of "program" to run programs in the current directory, but
      the increase in security is probably worth it.

-- 
Ted Timar - tmatimar@sunee.uwaterloo.ca
Empress Software, 3100 Steeles Ave E, Markham, Ont., Canada L3R 8T3

-----------------------------

From: Ted Timar <tmatimar@sunee.uwaterloo.ca>
Subject: Frequently Asked Questions about Unix (4/4) [Monthly posting]
Date: 9 Oct 92 05:03:15 GMT
Expires: Fri, 6 Nov 1992 05:00:14 GMT
Followup-To: comp.unix.questions
Supersedes: <unix-faq/part4_717397221@athena.mit.edu>
X-Last-Updated: 1992/09/24
To:       info-unix@sem.brl.mil

Archive-name: unix-faq/part4
Version: $Id: part4,v 1.6 92/09/11 09:15:32 tmatimar Exp $

These four articles contain the answers to some Frequently Asked
Questions often seen in comp.unix.questions and comp.unix.shell.
Please don't ask these questions again, they've been answered plenty
of times already - and please don't flame someone just because they may
not have read this particular posting.  Thank you.

These articles are divided approximately as follows:

      1.*) General questions.
      2.*) Relatively basic questions, likely to be asked by beginners.
      3.*) Intermediate questions.
      4.*) Advanced questions, likely to be asked by people who thought
	   they already knew all of the answers.

This article includes answers to:

      4.1)  How do I read characters from a terminal without requiring the user
              to hit RETURN?
      4.2)  How do I check to see if there are characters to be read without
              actually reading?
      4.3)  How do I find the name of an open file?
      4.4)  How can an executing program determine its own pathname?
      4.5)  How do I use popen() to open a process for reading AND writing?
      4.6)  How do I sleep() in a C program for less than one second?
      4.7)  How can I get setuid shell scripts to work?
      4.8)  How can I find out which user or process has a file open or is using
            a particular file system (so that I can unmount it?)
      4.9)  How do I keep track of people who are fingering me?
      4.10) Is it possible to reconnect a process to a terminal after it has
            been disconnected, e.g. after starting a program in the background
            and logging out?
      4.11) Is it possible to "spy" on a terminal, displaying the output
            that's appearing on it on another terminal?

    If you're looking for the answer to, say, question 4.5, and want to skip
    everything else, you can search ahead for the regular expression "^4.5)".

While these are all legitimate questions, they seem to crop up in
comp.unix.questions on an annual basis, usually followed by plenty
of replies (only some of which are correct) and then a period of
griping about how the same questions keep coming up.  You may also like
to read the monthly article "Answers to Frequently Asked Questions"
in the newsgroup "news.announce.newusers", which will tell you what
"UNIX" stands for.

With the variety of Unix systems in the world, it's hard to guarantee
that these answers will work everywhere.  Read your local manual pages
before trying anything suggested here.  If you have suggestions or
corrections for any of these answers, please send them to to
tmatimar@sunee.uwaterloo.ca.

4.1)  How do I read characters from a terminal without requiring the user
      to hit RETURN?

      Check out cbreak mode in BSD, ~ICANON mode in SysV.

      If you don't want to tackle setting the terminal parameters
      yourself (using the "ioctl(2)" system call) you can let the stty
      program do the work - but this is slow and inefficient, and you
      should change the code to do it right some time:

      #include <stdio.h>
      main()
      {
	    int c;

	    printf("Hit any character to continue\n");
	    /*
	     * ioctl() would be better here; only lazy
	     * programmers do it this way:
	     */
	    system("/bin/stty cbreak");        /* or "stty raw" */
	    c = getchar();
	    system("/bin/stty -cbreak");
	    printf("Thank you for typing %c.\n", c);

	    exit(0);
      }

      You might like to check out the documentation for the "curses"
      library of portable screen functions.  Often if you're interested
      in single-character I/O like this, you're also interested in
      doing some sort of screen display control, and the curses library
      provides various portable routines for both functions.

4.2)  How do I check to see if there are characters to be read without
      actually reading?

      Certain versions of UNIX provide ways to check whether characters
      are currently available to be read from a file descriptor.  In
      BSD, you can use select(2).  You can also use the FIONREAD ioctl
      (see tty(4)), which returns the number of characters waiting to
      be read, but only works on terminals, pipes and sockets.  In
      System V Release 3, you can use poll(2), but that only works on
      streams.  In Xenix - and therefore Unix SysV r3.2 and later - the
      rdchk() system call reports whether a read() call on a given file
      descriptor will block.

      There is no way to check whether characters are available to be
      read from a FILE pointer.  (You could poke around inside stdio
      data structures to see if the input buffer is nonempty, but that
      wouldn't work since you'd have no way of knowing what will happen
      the next time you try to fill the buffer.)

      Sometimes people ask this question with the intention of writing
	    if (characters available from fd)
		    read(fd, buf, sizeof buf);
      in order to get the effect of a nonblocking read.  This is not
      the best way to do this, because it is possible that characters
      will be available when you test for availability, but will no
      longer be available when you call read.  Instead, set the
      O_NDELAY flag (which is also called FNDELAY under BSD) using the
      F_SETFL option of fcntl(2).  Older systems (Version 7, 4.1 BSD)
      don't have O_NDELAY; on these systems the closest you can get to
      a nonblocking read is to use alarm(2) to time out the read.

4.3)  How do I find the name of an open file?

      In general, this is too difficult.  The file descriptor may
      be attached to a pipe or pty, in which case it has no name.
      It may be attached to a file that has been removed.  It may
      have multiple names, due to either hard or symbolic links.

      If you really need to do this, and be sure you think long
      and hard about it and have decided that you have no choice,
      you can use find with the -inum and possibly -xdev option,
      or you can use ncheck, or you can recreate the functionality
      of one of these within your program.  Just realize that
      searching a 600 megabyte filesystem for a file that may not
      even exist is going to take some time.

4.4)  How can an executing program determine its own pathname?

      Your program can look at argv[0]; if it begins with a "/", it is
      probably the absolute pathname to your program, otherwise your
      program can look at every directory named in the environment
      variable PATH and try to find the first one that contains an
      executable file whose name matches your program's argv[0] (which
      by convention is the name of the file being executed).  By
      concatenating that directory and the value of argv[0] you'd
      probably have the right name.

      You can't really be sure though, since it is quite legal for one
      program to exec() another with any value of argv[0] it desires.
      It is merely a convention that new programs are exec'd with the
      executable file name in argv[0].

      For instance, purely a hypothetical example:
	
	#include <stdio.h>
	main()
	{
	    execl("/usr/games/rogue", "vi Thesis", (char *)NULL);
	}

      The executed program thinks its name (its argv[0] value) is
      "vi Thesis".   (Certain other programs might also think that
      the name of the program you're currently running is "vi Thesis",
      but of course this is just a hypothetical example, don't
      try it yourself :-)

4.5)  How do I use popen() to open a process for reading AND writing?

      The problem with trying to pipe both input and output to an
      arbitrary slave process is that deadlock can occur, if both
      processes are waiting for not-yet-generated input at the same
      time.  Deadlock can be avoided only by having BOTH sides follow a
      strict deadlock-free protocol, but since that requires
      cooperation from the processes it is inappropriate for a
      popen()-like library function.

      The 'expect' distribution includes a library of functions that a
      C programmer can call directly.  One of the functions does the
      equivalent of a popen for both reading and writing.  It uses ptys
      rather than pipes, and has no deadlock problem.  It's portable to
      both BSD and SV.  See the next answer for more about 'expect'.

4.6)  How do I sleep() in a C program for less than one second?

      The first thing you need to be aware of is that all you can
      specify is a MINIMUM amount of delay; the actual delay will
      depend on scheduling issues such as system load, and could be
      arbitrarily large if you're unlucky.

      There is no standard library function that you can count on in
      all environments for "napping" (the usual name for short
      sleeps).  Some environments supply a "usleep(n)" function which
      suspends execution for n microseconds.  If your environment
      doesn't support usleep(), here are a couple of implementations
      for BSD and System V environments.

      The following code is adapted from Doug Gwyn's System V emulation
      support for 4BSD and exploits the 4BSD select() system call.
      Doug originally called it 'nap()'; you probably want to call it
      "usleep()";

      /*
	    usleep -- support routine for 4.2BSD system call emulations
	    last edit:	29-Oct-1984	D A Gwyn
      */

      extern int	select();

      int
      usleep( usec )				/* returns 0 if ok, else -1 */
	    long		usec;		/* delay in microseconds */
	    {
	    static struct			/* `timeval' */
		    {
		    long	tv_sec;		/* seconds */
		    long	tv_usec;	/* microsecs */
		    }	delay;		/* _select() timeout */

	    delay.tv_sec = usec / 1000000L;
	    delay.tv_usec = usec % 1000000L;

	    return select( 0, (long *)0, (long *)0, (long *)0, &delay );
	    }

      On System V you might do it this way:

      /*
      subseconds sleeps for System V - or anything that has poll()
      Don Libes, 4/1/1991

      The BSD analog to this function is defined in terms of
      microseconds while poll() is defined in terms of milliseconds.
      For compatibility, this function provides accuracy "over the long
      run" by truncating actual requests to milliseconds and
      accumulating microseconds across calls with the idea that you are
      probably calling it in a tight loop, and that over the long run,
      the error will even out.

      If you aren't calling it in a tight loop, then you almost
      certainly aren't making microsecond-resolution requests anyway,
      in which case you don't care about microseconds.  And if you did,
      you wouldn't be using UNIX anyway because random system
      indigestion (i.e., scheduling) can make mincemeat out of any
      timing code.

      Returns 0 if successful timeout, -1 if unsuccessful.

      */

      #include <poll.h>

      int
      usleep(usec)
      unsigned int usec;		/* microseconds */
      {
	    static subtotal = 0;	/* microseconds */
	    int msec;			/* milliseconds */

	    /* 'foo' is only here because some versions of 5.3 have
	     * a bug where the first argument to poll() is checked
	     * for a valid memory address even if the second argument is 0.
	     */
	    struct pollfd foo;

	    subtotal += usec;
	    /* if less then 1 msec request, do nothing but remember it */
	    if (subtotal < 1000) return(0);
	    msec = subtotal/1000;
	    subtotal = subtotal%1000;
	    return poll(&foo,(unsigned long)0,msec);
      }

      Another possibility for nap()ing on System V, and probably other
      non-BSD Unices is Jon Zeeff's s5nap package, posted to
      comp.sources.misc, volume 4.  It does require a installing a
      device driver, but works flawlessly once installed.  (Its
      resolution is limited to the kernel HZ value, since it uses the
      kernel delay() routine.)

4.7)  How can I get setuid shell scripts to work?

      [ This is a long answer, but it's a complicated and frequently-asked
        question.  Thanks to Maarten Litmaath for this answer, and
        for the "indir" program mentioned below. ]

      Let us first assume you are on a UNIX variant (e.g. 4.3BSD or
      SunOS) that knows about so-called `executable shell scripts'.
      Such a script must start with a line like:

	#!/bin/sh

      The script is called `executable' because just like a real (binary)
      executable it starts with a so-called `magic number' indicating
      the type of the executable.  In our case this number is `#!' and
      the OS takes the rest of the first line as the interpreter for
      the script, possibly followed by 1 initial option like:

	#!/bin/sed -f

      Suppose this script is called `foo' and is found in /bin,
      then if you type:

	foo arg1 arg2 arg3

      the OS will rearrange things as though you had typed:

	/bin/sed -f /bin/foo arg1 arg2 arg3

      There is one difference though: if the setuid permission bit for
      `foo' is set, it will be honored in the first form of the
      command; if you really type the second form, the OS will honor
      the permission bits of /bin/sed, which is not setuid, of course.

      ----------

      OK, but what if my shell script does NOT start with such a `#!'
      line or my OS does not know about it?

      Well, if the shell (or anybody else) tries to execute it, the OS
      will return an error indication, as the file does not start with
      a valid magic number.  Upon receiving this indication the shell
      ASSUMES the file to be a shell script and gives it another try:

	/bin/sh shell_script arguments

      But we have already seen that a setuid bit on `shell_script' will
      NOT be honored in this case!

      ----------

      Right, but what about the security risks of setuid shell scripts?

      Well, suppose the script is called `/etc/setuid_script', starting
      with:

	#!/bin/sh
	
      Now let us see what happens if we issue the following commands:

	$ cd /tmp
	$ ln /etc/setuid_script -i
	$ PATH=.
	$ -i

      We know the last command will be rearranged to:

	/bin/sh -i

      But this command will give us an interactive shell, setuid to the
      owner of the script!
      Fortunately this security hole can easily be closed by making the
      first line:

	#!/bin/sh -

      The `-' signals the end of the option list: the next argument `-i'
      will be taken as the name of the file to read commands from, just
      like it should!

      ---------

      There are more serious problems though:

	$ cd /tmp
	$ ln /etc/setuid_script temp
	$ nice -20 temp &
	$ mv my_script temp

      The third command will be rearranged to:

	nice -20 /bin/sh - temp

      As this command runs so slowly, the fourth command might be able
      to replace the original `temp' with `my_script' BEFORE `temp' is
      opened by the shell!  There are 4 ways to fix this security hole:

	1)  let the OS start setuid scripts in a different, secure way
	    - System V R4 and 4.4BSD use the /dev/fd driver to pass the
	    interpreter a file descriptor for the script

	2)  let the script be interpreted indirectly, through a frontend
	    that makes sure everything is all right before starting the
	    real interpreter - if you use the `indir' program from
	    comp.sources.unix the setuid script will look like this:

		#!/bin/indir -u
		#?/bin/sh /etc/setuid_script

	3)  make a `binary wrapper': a real executable that is setuid and
	    whose only task is to execute the interpreter with the name of
	    the script as an argument

	4)  make a general `setuid script server' that tries to locate the
	    requested `service' in a database of valid scripts and upon
	    success will start the right interpreter with the right
	    arguments.

      ---------

      Now that we have made sure the right file gets interpreted, are
      there any risks left?

      Certainly!  For shell scripts you must not forget to set the PATH
      variable to a safe path explicitly.  Can you figure out why?
      Also there is the IFS variable that might cause trouble if not
      set properly.  Other environment variables might turn out to
      compromise security as well, e.g. SHELL...  Furthermore you must
      make sure the commands in the script do not allow interactive
      shell escapes!  Then there is the umask which may have been set
      to something strange...

      Etcetera.  You should realise that a setuid script `inherits' all
      the bugs and security risks of the commands that it calls!

      All in all we get the impression setuid shell scripts are quite a
      risky business!  You may be better off writing a C program instead!

4.8)  How can I find out which user or process has a file open or is using
      a particular file system (so that I can unmount it?)

      Use fuser (system V), fstat (BSD), ofiles (public domain) or
      pff (public domain).  These programs will tell you various things
      about processes using particular files.

      A port of the 4.3 BSD fstat to Dynix, SunOS and Ultrix
      can be found in archives of comp.sources.unix, volume 18.

      pff is part of the kstuff package, and works on quite a few systems.
      Instructions for obtaining kstuff are provided in question 3.10.

4.9)  How do I keep track of people who are fingering me?

      Generally, you can't find out the userid of someone who is
      fingering you from a remote machine.  You may be able to
      find out which machine the remote request is coming from.
      One possibility, if your system supports it and assuming
      the finger daemon doesn't object, is to make your .plan file a
      "named pipe" instead of a plain file.  (Use 'mknod' to do this.)

      You can then start up a program that will open your .plan file
      for writing; the open will block until some other process (namely
      fingerd) opens the .plan for reading.  Now you can whatever you
      want through this pipe, which lets you show different .plan
      information every time someone fingers you.

      Of course, this may not work at all if your system doesn't
      support named pipes or if your local fingerd insists
      on having plain .plan files.

      Your program can also take the opportunity to look at the output
      of "netstat" and spot where an incoming finger connection is
      coming from, but this won't get you the remote user.

      Getting the remote userid would require that the remote site be
      running an identity service such as RFC 931.  There are now three
      RFC 931 implementations for popular BSD machines, and several
      applications (such as the wuarchive ftpd) supporting the server.
      For more information join the rfc931-users mailing list,
      rfc931-users-request@kramden.acf.nyu.edu.

      There are two caveats relating to this answer.  The first is that
      many NFS systems won't allow the recognize the named pipe
      correctly.  This means that trying to read the pipe on another
      machine will either block until it times out, or see it as a
      zero-length file, and never print it.

      The second problem is that on many systems, fingerd checks that
      the .plan file contains data (and is readable) before trying to
      read it.  This will not cause remote fingers to miss your .plan
      file entirely.

4.10) Is it possible to reconnect a process to a terminal after it has
      been disconnected, e.g. after starting a program in the background
      and logging out?

      Most variants of Unix do not support "detaching" and "attaching"
      processes, as operating systems such as VMS and Multics support.
      However, there are two freely redistributable packages which can
      be used to start processes in such a way that they can be later
      reattached to a terminal.

      The first is "screen," which is described in the
      comp.sources.unix archives as "Screen, multiple windows on a CRT"
      (see the "screen-3.2" package in comp.sources.misc, volume 28.)
      This package will run on at least BSD, System V r3.2 and SCO UNIX.

      The second is "pty," which is described in the comp.sources.unix
      archives as a package to "Run a program under a pty session" (see
      "pty" in volume 23).  pty is designed for use under BSD-like
      system only.

      Neither of these packages is retroactive, i.e. you must have
      started a process under screen or pty in order to be able to
      detach and reattach it.

4.11) Is it possible to "spy" on a terminal, displaying the output
      that's appearing on it on another terminal?

      There are a few different ways you can do this, although none
      of them is perfect:

      * kibitz allows two (or more) people to interact with a shell
        (or any arbitary program).  Uses include:

	- watching or aiding another person's terminal session;
	- recording a conversation while retaining the ability to
	  scroll backwards, save the conversation, or even edit it
	  while in progress;
	- teaming up on games, document editing, or other cooperative
	  tasks where each person has strengths and weakness that
	  complement one another.

        kibitz comes as part of the expect distribution.  See question 3.9.

        kibitz requires permission from the person to be spyed upon.  To
        spy without permission requires less pleasant approaches:

      * You can write a program that grovels through Kernel structures
        and watches the output buffer for the terminal in question,
        displaying characters as they are output.  This, obviously, is
        not something that should be attempted by anyone who does not
        have experience working with the Unix kernel.  Furthermore,
        whatever method you come up with will probably be quite
        non-portable.

      * If you want to do this to a particular hard-wired terminal all
        the time (e.g. if you want operators to be able to check the
        console terminal of a machine from other machines), you can
        actually splice a monitor into the cable for the terminal.  For
        example, plug the monitor output into another machine's serial
        port, and run a program on that port that stores its input
        somewhere and then transmits it out *another* port, this one
        really going to the physical terminal.  If you do this, you have
        to make sure that any output from the terminal is transmitted
        back over the wire, although if you splice only into the
        computer->terminal wires, this isn't much of a problem.  This is
        not something that should be attempted by anyone who is not very
        familiar with terminal wiring and such.

-- 
Ted Timar - tmatimar@sunee.uwaterloo.ca
Empress Software, 3100 Steeles Ave E, Markham, Ont., Canada L3R 8T3

-----------------------------

From: Ted Timar <tmatimar@sunee.uwaterloo.ca>
Subject: Frequently Asked Questions about Unix (3/4) [Monthly posting]
Date: 9 Oct 92 05:03:37 GMT
Expires: Fri, 6 Nov 1992 05:00:14 GMT
Followup-To: comp.unix.questions
Supersedes: <unix-faq/part3_717397221@athena.mit.edu>
X-Last-Updated: 1992/09/24
To:       info-unix@sem.brl.mil

Archive-name: unix-faq/part3
Version: $Id: part3,v 1.6 92/09/11 09:15:30 tmatimar Exp $

These four articles contain the answers to some Frequently Asked
Questions often seen in comp.unix.questions and comp.unix.shell.
Please don't ask these questions again, they've been answered plenty
of times already - and please don't flame someone just because they may
not have read this particular posting.  Thank you.

These articles are divided approximately as follows:

      1.*) General questions.
      2.*) Relatively basic questions, likely to be asked by beginners.
      3.*) Intermediate questions.
      4.*) Advanced questions, likely to be asked by people who thought
	   they already knew all of the answers.

This article includes answers to:

      3.1)  How do I find out the creation time of a file?
      3.2)  How do I use "rsh" without having the rsh hang around
              until the remote command has completed?
      3.3)  How do I truncate a file?
      3.4)  Why doesn't find's "{}" symbol do what I want?
      3.5)  How do I set the permissions on a symbolic link?
      3.6)  How do I "undelete" a file?
      3.7)  How can a process detect if it's running in the background?
      3.8)  Why doesn't redirecting a loop work as intended?  (Bourne shell)
      3.9)  How do I run 'passwd', 'ftp', 'telnet', 'tip' and other interactive
              programs from a shell script or in the background?
      3.10) How do I find out the process ID of a program with a particular
            name from inside a shell script or C program?
      3.11) How do I check the exit status of a remote command
            executed via "rsh" ?
      3.12) Is it possible to pass shell variable settings into an awk program?
      3.13) How do I get rid of zombie processes that persevere?
      3.14) How do I get lines from a pipe as they are written instead of
            only in larger blocks.

    If you're looking for the answer to, say, question 3.5, and want to skip
    everything else, you can search ahead for the regular expression "^3.5)".

While these are all legitimate questions, they seem to crop up in
comp.unix.questions on an annual basis, usually followed by plenty
of replies (only some of which are correct) and then a period of
griping about how the same questions keep coming up.  You may also like
to read the monthly article "Answers to Frequently Asked Questions"
in the newsgroup "news.announce.newusers", which will tell you what
"UNIX" stands for.

With the variety of Unix systems in the world, it's hard to guarantee
that these answers will work everywhere.  Read your local manual pages
before trying anything suggested here.  If you have suggestions or
corrections for any of these answers, please send them to to
tmatimar@sunee.uwaterloo.ca.

3.1)  How do I find out the creation time of a file?

      You can't - it isn't stored anywhere.  Files have a last-modified
      time (shown by "ls -l"), a last-accessed time (shown by "ls -lu")
      and an inode change time (shown by "ls -lc"). The latter is often
      referred to as the "creation time" - even in some man pages -
      but that's wrong; it's also set by such operations as mv, ln,
      chmod, chown and chgrp.

      The man page for "stat(2)" discusses this.

3.2)  How do I use "rsh" without having the rsh hang around until the
      remote command has completed?

      (See note in question 2.7 about what "rsh" we're talking about.)

      The obvious answers fail:
      	    rsh machine command &
      or      rsh machine 'command &'

      For instance, try doing   rsh machine 'sleep 60 &' and you'll see
      that the 'rsh' won't exit right away.  It will wait 60 seconds
      until the remote 'sleep' command finishes, even though that
      command was started in the background on the remote machine.  So
      how do you get the 'rsh' to exit immediately after the 'sleep' is
      started?

      The solution - if you use csh on the remote machine:

	    rsh machine -n 'command >&/dev/null </dev/null &'

      If you use sh on the remote machine:

	    rsh machine -n 'command >/dev/null 2>&1 </dev/null &'

      Why?  "-n" attaches rsh's stdin to /dev/null so you could run the
      complete rsh command in the background on the LOCAL machine.
      Thus "-n" is equivalent to another specific "< /dev/null".
      Furthermore, the input/output redirections on the REMOTE machine
      (inside the single quotes) ensure that rsh thinks the session can
      be terminated (there's no data flow any more.)

      Note: The file that you redirect to/from on the remote machine
      doesn't have to be /dev/null; any ordinary file will do.

      In many cases, various parts of these complicated commands
      aren't necessary.

3.3)  How do I truncate a file?

      The BSD function ftruncate() sets the length of a file.  Xenix -
      and therefore SysV r3.2 and later - has the chsize() system
      call.  For other systems, the only kind of truncation you can do
      is truncation to length zero with creat() or open(..., O_TRUNC).

3.4)  Why doesn't find's "{}" symbol do what I want?

      "find" has a -exec option that will execute a particular command
      on all the selected files. Find will replace any "{}" it sees
      with the name of the file currently under consideration.

      So, some day you might try to use "find" to run a command on
      every file, one directory at a time.  You might try this:

	find /path -type d -exec command {}/\* \;

      hoping that find will execute, in turn

	command directory1/*
	command directory2/*
	...

      Unfortunately, find only expands the "{}" token when it appears
      by itself.  Find will leave anything else like "{}/*" alone, so
      instead of doing what you want, it will do

	command {}/*
	command {}/*
	...

      once for each directory.  This might be a bug, it might be a
      feature, but we're stuck with the current behaviour.

      So how do you get around this?  One way would be to write a
      trivial little shell script, let's say "./doit", that consists of

	command "$1"/*

      You could then use

	find /path -type d -exec ./doit {} \;

      Or if you want to avoid the "./doit" shell script, you can use

	find /path -type d -exec sh -c 'command $0/*' {} \;

      (This works because within the 'command' of "sh -c 'command' A B C ...",
       $0 expands to A, $1 to B, and so on.)

      or you can use the construct-a-command-with-sed trick

	find /path -type d -print | sed 's:.*:command &/*:' | sh

      If all you're trying to do is cut down on the number of times
      that "command" is executed, you should see if your system has the
      "xargs" command.  Xargs reads arguments one line at a time from
      the standard input and assembles as many of them as will fit into
      one command line.  You could use

	find /path -print | xargs command

      which would result in one or more executions of

	command file1 file2 file3 file4 dir1/file1 dir1/file2

      Unfortunately this is not a perfectly robust or secure solution.
      Xargs expects its input lines to be terminated with newlines, so
      it will be confused by files with odd characters such as newlines
      in their names.

3.5)  How do I set the permissions on a symbolic link?

      Permissions on a symbolic link don't really mean anything.  The
      only permissions that count are the permissions on the file that
      the link points to.

3.6)  How do I "undelete" a file?

      Someday, you are going to accidentally type something like "rm *
      .foo", and find you just deleted "*" instead of "*.foo".
      Consider it a rite of passage.

      Of course, any decent systems administrator should be doing
      regular backups.  Check with your sysadmin to see if a recent
      backup copy of your file is available.  But if it isn't, read
      on.

      For all intents and purposes, when you delete a file with "rm" it
      is gone.  Once you "rm" a file, the system totally forgets which
      blocks scattered around the disk comprised your file.  Even
      worse, the blocks from the file you just deleted are going to be
      the first ones taken and scribbled upon when the system needs
      more disk space.  However, never say never.  It is theoretically
      possible *if* you shut down the system immediately after the "rm"
      to recover portions of the data.  However, you had better have a
      very wizardly type person at hand with hours or days to spare to
      get it all back.

      Your first reaction when you "rm" a file by mistake is why not
      make a shell alias or procedure which changes "rm" to move files
      into a trash bin rather than delete them?  That way you can
      recover them if you make a mistake, and periodically clean out
      your trash bin.  Two points:  first, this is generally accepted
      as a *bad* idea.  You will become dependent upon this behaviour
      of "rm", and you will find yourself someday on a normal system
      where "rm" is really "rm", and you will get yourself in trouble.
      Second, you will eventually find that the hassle of dealing with
      the disk space and time involved in maintaining the trash bin, it
      might be easier just to be a bit more careful with "rm".  For
      starters, you should look up the "-i" option to "rm" in your
      manual.

      If you are still undaunted, then here is a possible simple
      answer.  You can create yourself a "can" command which moves
      files into a trashcan directory. In csh(1) you can place the
      following commands in the ".login" file in your home directory:

	alias can	'mv \!* ~/.trashcan'	   # junk file(s) to trashcan
	alias mtcan	'rm -f ~/.trashcan/*'	   # irretrievably empty trash
	if ( ! -d ~/.trashcan ) mkdir ~/.trashcan  # ensure trashcan exists

      You might also want to put a:

	rm -f ~/.trashcan/*

      in the ".logout" file in your home directory to automatically
      empty the trash when you log out.  (sh and ksh versions are left
      as an exercise for the reader.)

      MIT's Project Athena has produced a comprehensive
      delete/undelete/expunge/purge package, which can serve as a
      complete replacement for rm which allows file recovery.  This
      package was posted to comp.sources.misc (volume 17, issue
      023-026)

3.7)  How can a process detect if it's running in the background?

      First of all: do you want to know if you're running in the
      background, or if you're running interactively? If you're
      deciding whether or not you should print prompts and the like,
      that's probably a better criterion. Check if standard input
      is a terminal:

	    sh: if [ -t 0 ]; then ... fi
	    C: if(isatty(0)) { ... }

      In general, you can't tell if you're running in the background.
      The fundamental problem is that different shells and different
      versions of UNIX have different notions of what "foreground" and
      "background" mean - and on the most common type of system with a
      better-defined notion of what they mean, programs can be moved
      arbitrarily between foreground and background!

      UNIX systems without job control typically put a process into the
      background by ignoring SIGINT and SIGQUIT and redirecting the
      standard input to "/dev/null"; this is done by the shell.

      Shells that support job control, on UNIX systems that support job
      control, put a process into the background by giving it a process
      group ID different from the process group to which the terminal
      belongs.  They move it back into the foreground by setting the
      terminal's process group ID to that of the process.  Shells that
      do *not* support job control, on UNIX systems that support job
      control, typically do what shells do on systems that don't
      support job control.

3.8)  Why doesn't redirecting a loop work as intended?  (Bourne shell)

      Take the following example:

	foo=bar

	while read line
	do
		# do something with $line
		foo=bletch
	done < /etc/passwd

	echo "foo is now: $foo"

      Despite the assignment ``foo=bletch'' this will print
      ``foo is now: bar'' in many implementations of the Bourne shell.
      Why?  Because of the following, often undocumented, feature of
      historic Bourne shells: redirecting a control structure (such as
      a loop, or an ``if'' statement) causes a subshell to be created,
      in which the structure is executed; variables set in that
      subshell (like the ``foo=bletch'' assignment) don't affect the
      current shell, of course.

      The POSIX 1003.2 Shell and Tools Interface standardization
      committee forbids the behaviour described above, i.e. in P1003.2
      conformant Bourne shells the example will print ``foo is now:
      bletch''.

      In historic (and P1003.2 conformant) implementations you can use
      the following `trick' to get around the redirection problem:

	foo=bar

	# make file descriptor 9 a duplicate of file descriptor 0 (stdin);
	# then connect stdin to /etc/passwd; the original stdin is now
	# `remembered' in file descriptor 9; see dup(2) and sh(1)
	exec 9<&0 < /etc/passwd

	while read line
	do
		# do something with $line
		foo=bletch
	done

	# make stdin a duplicate of file descriptor 9, i.e. reconnect
	# it to the original stdin; then close file descriptor 9
	exec 0<&9 9<&-

	echo "foo is now: $foo"

      This should always print ``foo is now: bletch''.
      Right, take the next example:

	foo=bar

	echo bletch | read foo

	echo "foo is now: $foo"

      This will print ``foo is now: bar'' in many implementations,
      ``foo is now: bletch'' in some others.  Why?  Generally each part
      of a pipeline is run in a different subshell; in some
      implementations though, the last command in the pipeline is made
      an exception: if it is a builtin command like ``read'', the
      current shell will execute it, else another subshell is created.

      POSIX 1003.2 allows both behaviours so portable scripts cannot
      depend on any of them.

3.9)  How do I run 'passwd', 'ftp', 'telnet', 'tip' and other interactive
      programs from a shell script or in the background?

      These programs expect a terminal interface.  Shells makes no
      special provisions to provide one.  Hence, such programs cannot
      be automated in shell scripts.

      The 'expect' program provides a programmable terminal interface
      for automating interaction with such programs.  The following
      expect script is an example of a non-interactive version of
      passwd(1).

	# username is passed as 1st arg, password as 2nd
	set password [index $argv 2]
	spawn passwd [index $argv 1]
	expect "*password:"
	send "$password\r"
	expect "*password:"
	send "$password\r"
	expect eof

      expect can partially automate interaction which is especially
      useful for telnet, rlogin, debuggers or other programs that have
      no built-in command language.  The distribution provides an
      example script to rerun rogue until a good starting configuration
      appears.  Then, control is given back to the user to enjoy the game.

      Fortunately some programs have been written to manage the
      connection to a pseudo-tty so that you can run these sorts of
      programs in a script.

      To get expect, email "send pub/expect/expect.shar.Z" to
      library@cme.nist.gov or anonymous ftp same from
      durer.cme.nist.gov.

      Another solution is provided by the pty 4.0 program, which runs a
      program under a pseudo-tty session and was posted to
      comp.sources.unix, volume 25.  A pty-based solution using named
      pipes to do the same as the above might look like this:

	#!/bin/sh
	/etc/mknod out.$$ p; exec 2>&1
	( exec 4<out.$$; rm -f out.$$
	<&4 waitfor 'password:'
	    echo "$2"
	<&4 waitfor 'password:'
	    echo "$2"
	<&4 cat >/dev/null
	) | ( pty passwd "$1" >out.$$ )

      Here, 'waitfor' is a simple C program that searches for
      its argument in the input, character by character.

      A simpler pty solution (which has the drawback of not
      synchronizing properly with the passwd program) is

	#!/bin/sh
	( sleep 5; echo "$2"; sleep 5; echo "$2") | pty passwd "$1"

3.10) How do I find out the process ID of a program with a particular
      name from inside a shell script or C program?

      In a shell script:

      There is no utility specifically designed to map between program
      names and process IDs.  Furthermore, such mappings are often
      unreliable, since it's possible for more than one process to have
      the same name, and since it's possible for a process to change
      its name once it starts running.  However, a pipeline like this
      can often be used to get a list of processes (owned by you) with
      a particular name:

	    ps ux | awk '/name/ && !/awk/ {print $2}'

      You replace "name" with the name of the process for which you are
      searching.

      The general idea is to parse the output of ps, using awk or grep
      or other utilities, to search for the lines with the specified
      name on them, and print the PID's for those lines.  Note that the
      "!/awk/" above prevents the awk process for being listed.

      You may have to change the arguments to ps, depending on what
      kind of Unix you are using.

      In a C program:

      Just as there is no utility specifically designed to map between
      program names and process IDs, there are no (portable) C library
      functions to do it either.

      However, some vendors provide functions for reading Kernel
      memory; for example, Sun provides the "kvm_" functions, and Data
      General provides the "dg_" functions.  It may be possible for any
      user to use these, or they may only be useable by the super-user
      (or a user in group "kmem") if read-access to kernel memory on
      your system is restricted.  Furthermore, these functions are
      often not documented or documented badly, and might change from
      release to release.

      Some vendors provide a "/proc" filesystem, which appears as a
      directory with a bunch of filenames in it.  Each filename is a
      number, corresponding to a process ID, and you can open the file
      and read it to get information about the process.  Once again,
      access to this may be restricted, and the interface to it may
      change from system to system.

      If you can't use vendor-specific library functions, and you
      don't have /proc, and you still want to do this completely
      in C, you
      are going to have to do the grovelling through kernel memory
      yourself.  For a good example of how to do this on many systems,
      see the sources to "ofiles", available in the comp.sources.unix
      archives.  (A package named "kstuff" to help with kernel
      grovelling was posted to alt.sources in May 1991 and is also
      available via anonymous ftp as
      usenet/alt.sources/articles/{329{6,7,8,9},330{0,1}}.Z from
      wuarchive.wustl.edu.)

3.11) How do I check the exit status of a remote command
      executed via "rsh" ?

      This doesn't work:

	rsh some-machine some-crummy-command || echo "Command failed"

      The exit status of 'rsh' is 0 (success) if the rsh program
      itself completed successfully, which probably isn't what
      you wanted.

      If you want to check on the exit status of the remote program,
      you can try using Maarten Litmaath's 'ersh' script, which was
      posted to alt.sources in January, 1991.  ersh is a shell script
      that calls rsh, arranges for the remote machine to echo the
      status of the command after it completes, and exits with that
      status.

3.12) Is it possible to pass shell variable settings into an awk program?

      There are two different ways to do this.  The first involves
      simply expanding the variable where it is needed in the program.
      For example, to get a list of all ttys you're using:

	who | awk '/^'"$USER"'/ { print $2 }'				(1)

      Single quotes are usually used to enclose awk programs because
      the character '$' is often used in them, and '$' will be
      interpreted by the shell if enclosed inside double quotes, but
      not if enclosed inside single quotes.  In this case, we *want*
      the '$' in "$USER" to be interpreted by the shell, so we close
      the single quotes and then put the "$USER" inside double quotes.
      Note that there are no spaces in any of that, so the shell will
      see it all as one argument.  Note, further, that the double
      quotes probably aren't necessary in this particular case (i.e. we
      could have done

	who | awk '/^'$USER'/ { print $2 }'				(2)

      ), but they should be included nevertheless because they are
      necessary when the shell variable in question contains special
      characters or spaces.

      The second way to pass variable settings into awk is to use an
      often undocumented feature of awk which allows variable settings
      to be specified as "fake file names" on the command line.  For
      example:

	who | awk '$1 == user { print $2 }' user="$USER" -		(3)

      Variable settings take effect when they are encountered on the
      command line, so, for example, you could instruct awk on how to
      behave for different files using this technique.  For example:

	awk '{ program that depends on s }' s=1 file1 s=0 file2		(4)

      Note that some versions of awk will cause variable settings
      encountered before any real filenames to take effect before the
      BEGIN block is executed, but some won't so neither way should be
      relied upon.

      Note, further, that when you specify a variable setting, awk
      won't automatically read from stdin if no real files are
      specified, so you need to add a "-" argument to the end of your
      command, as I did at (3) above.

3.13) How do I get rid of zombie processes that persevere?

      From: jik@pit-manager.MIT.Edu (Jonathan I. Kamens)
      Date: Fri, 17 Jan 92 14:40:09 -0500

      Unfortunately, it's impossible to generalize how the death of
      child processes should behave, because the exact mechanism varies
      over the various flavors of Unix.

      First of all, by default, you have to do a wait() for child
      processes under ALL flavors of Unix.  That is, there is no flavor
      of Unix that I know of that will automatically flush child
      processes that exit, even if you don't do anything to tell it to
      do so.

      Second, under some SysV-derived systems, if you do
      "signal(SIGCHLD, SIG_IGN)" (well, actually, it may be SIGCLD
      instead of SIGCHLD, but most of the newer SysV systems have
      "#define SIGCHLD SIGCLD" in the header files), then child
      processes will be cleaned up automatically, with no further
      effort in your part.  The best way to find out if it works at
      your site is to try it, although if you are trying to write
      portable code, it's a bad idea to rely on this in any case.
      Unfortunately, POSIX doesn't allow you to do this; the behavior
      of setting the SIGCHLD to SIG_IGN under POSIX is undefined, so
      you can't do it if your program is supposed to be
      POSIX-compliant.

      If you can't use SIG_IGN to force automatic clean-up, then you've
      got to write a signal handler to do it.  It isn't easy at all to
      write a signal handler that does things right on all flavors of
      Unix, because of the following inconsistencies:

      On some flavors of Unix, the SIGCHLD signal handler is called if
      one *or more* children have died.  This means that if your signal
      handler only does one wait() call, then it won't clean up all of
      the children.  Fortunately, I believe that all Unix flavors for
      which this is the case have available to the programmer the
      wait3() call, which allows the WNOHANG option to check whether or
      not there are any children waiting to be cleaned up.  Therefore,
      on any system that has wait3(), your signal handler should call
      wait3() over and over again with the WNOHANG option until there
      are no children left to clean up.

      On SysV-derived systems, SIGCHLD signals are regenerated if there
      are child processes still waiting to be cleaned up after you exit
      the SIGCHLD signal handler.  Therefore, it's safe on most SysV
      systems to assume when the signal handler gets called that you
      only have to clean up one signal, and assume that the handler
      will get called again if there are more to clean up after it
      exits.

      On older systems, signal handlers are automatically reset to
      SIG_DFL when the signal handler gets called.  On such systems,
      you have to put "signal(SIGCHILD, catcher_func)" (where
      "catcher_func" is the name of the handler function) as the first
      thing in the signal handler, so that it gets reset.
      Unfortunately, there is a race condition which may cause you to
      get a SIGCHLD signal and have it ignored between the time your
      handler gets called and the time you reset the signal.
      Fortunately, newer implementations of signal() don't reset the
      handler to SIG_DFL when the handler function is called.  To get
      around this problem, on systems that do not have wait3() but do
      have SIGCLD, you need to reset the signal handler with a call to
      signal() after doing at least one wait() within the handler, each
      time it is called.

      The summary of all this is that on systems that have wait3(), you
      should use that and your signal handler should loop, and on
      systems that don't, you should have one call to wait() per
      invocation of the signal handler.

      One more thing -- if you don't want to go through all of this
      trouble, there is a portable way to avoid this problem, although
      it is somewhat less efficient.  Your parent process should fork,
      and then wait right there and then for the child process to
      terminate.  The child process then forks again, giving you a
      child and a grandchild.  The child exits immediately (and hence
      the parent waiting for it notices its death and continues to
      work), and the grandchild does whatever the child was originally
      supposed to.  Since its parent died, it is inherited by init,
      which will do whatever waiting is needed.  This method is
      inefficient because it requires an extra fork, but is pretty much
      completely portable.

3.14) How do I get lines from a pipe as they are written instead of only in
      larger blocks.

      From: jik@pit-manager.MIT.Edu (Jonathan I. Kamens)
      Date: Sun, 16 Feb 92 20:59:28 -0500

      The stdio library does buffering differently depending on whether
      it thinks it's running on a tty.  If it thinks it's on a tty, it
      does buffering on a per-line basis; if not, it uses a larger
      buffer than one line.

      If you have the source code to the client whose buffering you
      want to disable, you can use setbuf() or setvbuf() to change the
      buffering.

      If not, the best you can do is try to convince the program that
      it's running on a tty by running it under a pty, e.g. by using
      the "pty" program mentioned in question 3.9.

-- 
Ted Timar - tmatimar@sunee.uwaterloo.ca
Empress Software, 3100 Steeles Ave E, Markham, Ont., Canada L3R 8T3

-----------------------------

From: "Hetland, Thor Henning  7-93" <ARTEMIS@gribb.hsr.no>
Subject: Device driver (I/O)
Date: 9 Oct 92 08:46:21 GMT
To:       info-unix@sem.brl.mil


Do anyone out there have an C-example of an I/O device driver?  We are doing 
one right now, and would like to check out some tricks..

Please e-mail any responce.

TSM.

-----------------------------

From: Alan Yasutovich <yasu@ll.mit.edu>
Subject: Printing to a serial postscript printer hangs printer.
Date: 9 Oct 92 12:11:26 GMT
To:       info-unix@sem.brl.mil


	I have a xyplex terminal server on the network.  Xyplex
	provides a printer of.

	The print to the ASCII printer has always worked.  

	When I send postscript, the "busy light" comes on and stays
	on.  Also, there are 2 ways to do it. "By hand" to the filter,
	and lpr.

	Doing it by hand prints successfully, but the light continues
	to flash.  using lpr gives no printout, and hangs the printer
	for a power-down reset.

	I believe at least that there is some kind of bogus character
	there.

	It was suggested that I put a cntrl D as the last character
	in the file.  This made no difference.

	Any ideas?

-- 
	Alan Yasutovich
	"inquiring  (and nosey) minds WANT TO KNOW!!!"
	I can remember when "safe sex" meant having a padded headboard!!
	Tick Tock.....Tick Tock......Tick Tock .....Tick Tock......

-----------------------------

From: Harley Davis <davis@passy.ilog.fr>
Subject: When to use libcurses
Date: 9 Oct 92 16:53:53 GMT
To:       info-unix@sem.brl.mil


Is there any reason not to use the curses library for controlling a
terminal within a portable program?  It seems to exist on all Unices
of interest as well as VMS, yet GNU Emacs does not seem to use it in
most cases.  This makes me wonder if there is some problem with it.

-- Harley Davis
--

 ------------------------------------------------------------------------------
nom: Harley Davis			ILOG S.A.
net: davis@ilog.fr			2 Avenue Gallie'ni, BP 85
tel: (33 1) 46 63 66 66			94253 Gentilly Cedex, France

-----------------------------

From: Sarah Skovronsky <starfish@stein.u.washington.edu>
Subject: .signatures, fortune files, etc.
Date: 9 Oct 92 21:20:10 GMT
To:       info-unix@sem.brl.mil

I'd like to set up a .signature that would include a randomly-chosen quote
each time I used it.  Or, failing that, set up my own fortune file so I
can at least have random sayings, if not imbedded in the signature.  Does
anyone know how I could go about doing this?

-- 
                                   Please note new address
**********************************vvvvvvvvvvvvvvvvvvvvvvvvv*************
*            Sarah Skovronsky     starfish@u.washington.edu            *
* "Sample my FIST, you community theater reject!"  --TV's Frank, MST3K *
**********fnord!********furrfu!********hi-keeba!********meep!***********

-----------------------------

From: Tim McDonough CSC   <mcdono@nosc.mil>
Subject: Problem with dd and tar file on exabyte
Date: 9 Oct 92 21:22:43 GMT
To:       info-unix@sem.brl.mil

Greetings 
	I want to copy a tar file from one exabyte tape to another. 
	I've been using dd/cpio to copy the single tar file 
	with little luck. I've tried ibs/bs=8196 . Tar has no 
	problem extracting the files. Using a SPARCstation 1+ 4.1.2

fizzle 18> /usr/bin/dd if=/dev/rst9 files=1 of=/dev/rst6 
st1:	Error for command 'read', Error Level: 'Fatal'
    	Block: 0	File Number: 0
    	Sense Key: No Additional Sense
	Incorrect Length Indicator Set
dd: read: I/O error
0+0 records in
0+0 records out


---
Tim McDonough                   |   The opinions voiced are my own and
Computer Sciences Corp.         |   do not reflect those of my employer
mcdono@sunspot.nosc.mil         |   or the Susquehanna Hat Company.

-----------------------------

From: Dave Morgan <dmorgan@javelin.sim.es.com>
Subject: Converting comp_t type to something more integerish.
Date: 9 Oct 92 22:15:57 GMT
To:       info-unix@sem.brl.mil


     We are trying to track the usage of a software package we have
to determine how many licenses we need.  Turning on Sun's accounting
appears to record every invocation of a process, exactly what we need.
I have no problem opening the file /var/adm/pacct and running through
it reading in acct structs.  I just can't tell how long the process ran
(elapsed time) since I don't know how to get this elapsed time from comp_t
to something I can use.
     I'd use sa, but it doesn't tell me how many of the processes were running
at any given time and how long each session lasted.  This is what I need for
license info.

     man 5 acct gives:
	The type comp_t is a 3 bits base 8 exponent, 13 bit fraction
	     ``floating   point''   number.

     Any help appreciated...

-Dave
-- 
-* Dave Morgan                                    System Programmer
dmorgan@javelin.sim.es.com            Evans & Sutherland Computer Corporation
 ...uunet!javelin.sim.es.com!dmorgan         "Carpedium - Sieze the day"

-----------------------------

From: Marty Collins <mcollins@db.SJF.Novell.COM>
Subject: Re: PC/NFS vs Netware
Date: 9 Oct 92 23:49:53 GMT
X-Newsreader: Tin 1.1 PL4
To:       info-unix@sem.brl.mil

kumeda@beach.csulb.edu (ANDY KUMEDA) writes:
: Sorry if this topic has been brought up before...
: 
: The question:  Should we use Sun's PC/NFS or Novell's Netware?!?
: I mainly would like a summary of Pros and Cons between the two.

You are asking about comparing apples and oranges.

Are you heavily vested in DOS workstations or UNIX workstations?

If you are vested heavier in one side then that shows which platform
to use.

If the type of machines is even then you need to ask yourself do you
need connectivity between both worlds?

If so then you could run Netware on a central server that would allow
DOS clients access to file and print services. Then you could either
by Netware NFS that would allow UNIX users access to the same Netware
file and print services.  The two products together would be
$4,995 for Netware NFS and $4,995 for 50 user version of Netware 3.11.

Or you could get Portable Netware or Netware for Sun for your Sun.
I don't know the cost of this particular product.

If you wanted to load PC-NFS on Dos workstation and have seemless connectivity
to both Netware and Sun at the same time it can be done for a resonable
memory hit. Running both the Netware shell and PC-NFS shell with the
correct modules will run you about 70-100K with reasonable memory management. 

Then you will have the overhead of running the NFS protocol right from your
workstation compared to using a centralized server to be the
middle point between the Dos/Netware and UNix/NFS world.
You must install PC-NFS on all workstations that you want this connectivity
compared to installing NFS on just the Netware server that should have the
high amount of memory and faster processor, hopefully.



: 
: Things that should be considered:
: 	1) Hardware requirements. (Note: we already have an Ethernet network
:       established.)
:       a.  Server cost/type 
:    2) Software requirments.
:       a.  Server software cost 
:       b.  Client software cost
:    3) Advantages vs Disadvantages between the two
:       a.  Will the end-user notice any difference?!?
:       b.  Which is easier to administer?!?
:       c.  Print capabilities?!?
:       d.  Misc. (ie other important issues)
: 
: If it's of any significance, our site consists of several hundred 
: PC's (286's, 386/25, 386/33) all connected by UTP Ethernet.
: 
: Please e-mail responses as I do not read all the newsgroups that I
: posted to -- I will summarize later. 
: 
: Thank you.
: 
: Andy Kumeda
: US Naval Weapons Station, Seal Beach
: (310) 594-7114
: kumeda@hawk.nwac.sea06.navy.mil
: kumeda@csulb.edu
: 

--
		
	   A woman needs a man like a fish needs a bicycle.

	                				U2 
							Tryin to throw your
							arms around the world.

   Marty Collins
   Product Support
   NOVELL, INC.  San Jose, CA.        
   mcollins@novell.com 
   1-800-NETWARE  

-----------------------------

From: Jim Gasprich <jimg@ocean.rutgers.edu>
Subject: prtvtoc (SVR4) vs. dkinfo (SUN OS 4.1.1)
Keywords: prtvtoc
Date: 10 Oct 92 00:28:23 GMT
To:       info-unix@sem.brl.mil

I am stuck with a couple of OKIstations and their storage devices, I'd like
to move the 600 M drives onto a SUN SPARCstation IPC (SUN OS 4.1.1). What I
need is info (# cyls, etc.) on the OKI drives so that the info can be used
in the SUN's format program.

OKI has since gone belly-up (if you have any of their machines, you would
understand why), so I have no one to pesker on the phone. The OKIs use
SVR4, and we have some feeble manuals from Intel which have helped, but not
enough.

In SUN OS, there is a command called dkinfo, which gives info on a disk, i.e.:
	#dkinfo sd0

	sd0: Emulex MD21 controller at addr f8800000, unit # 24
	1254 cylinders 9 heads 36 sectors/track
	a: 16848 sectors (52 cyls)
	   starting cylinder 0
	b: 65448 sectors (202 cyls)
	   starting cylinder 52
	c: 406296 sectors (1254 cyls)
	   starting cylinder 0
	d: No such device or address
	e: No such device or address
	f: No such device or address
	g: 283176 sectors (874 cyls)
	   starting cylinder 254
	h: 40824 sectors (126 cyls)
	   starting cylinder 1128

In SVR4, there is a command called prtvtoc (print Volume Table of Contents),
which should give me what I want, but alas, does not seem to work. Here's the
lowdown:

	# df
	/         (/dev/root       ):  48872 blocks   46804 files
	/proc     (/proc           ):      0 blocks     143 files
	/dev/fd   (/dev/fd         ):      0 blocks       0 files
	/stand    (/dev/dsk/c0t0d0sa):   6425 blocks      92 files
	/grass    (/dev/dsk/c0t1d0s1): 665250 blocks   40822 files

(the last listing is the disk I want info on)

	# prtvtoc /dev/rdsk/c0t1d0s1
	prtvtoc: device /dev/rdsk/c0t1d0s1 is not a slice 0 device
	prtvtoc [-a] [-e] [-p] [-f filename] raw-device

I'm a little lost as to the error message, and the manual does not even give
a listing of the other options.

Any help or clues would be greatly appreciated. Thanks.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Jim Gasprich                            e-mail: jimg@ocean.rutgers.edu
Research & Support Slave                tel:    (908) 932-9631
Cook College Remote Sensing Center      fax:    (908) 932-8644
Rutgers University
PO Box 231
New Brunswick, NJ, O8903        "Du bist mein Gweckman" - Anonymous Fascist
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

-----------------------------

From: "Chris M. Cavers" <cavers@menudo.uh.edu>
Subject: kernel to nonkernel ipc
Date: 10 Oct 92 04:02:26 GMT
To:       info-unix@sem.brl.mil

I would like to have my device driver communicate with a user level process.
The ioctl call is fine for short data transfers (128 or 255 bytes) but
I need to send over several thousand bytes at one time.

My questions are:
	a) which method does the kernel use (sockets,message queues,
			shared memory w/semaphores)
	b) If I want to send messages from kernel (e.g. device driver) to
			user level processes, is it ok to use message queues?

-----------------------------

From: "Chris M. Cavers" <cavers@menudo.uh.edu>
Subject: rn
Date: 10 Oct 92 04:05:33 GMT
To:       info-unix@sem.brl.mil

How do I kill the signtures from message when I use rn.
I couldn't find this in the manual pages.

-----------------------------

From: David Fox <bbs.barfeau@goonsquad.spies.com>
Subject: PKZIP for unix? (pkzip version 1.10)
Date: 10 Oct 92 05:35:46 GMT
To:       info-unix@sem.brl.mil

Hi. I've acquired a version of zip/unzip for unix (BSD) that works
but it's compatible with version 1.93a (DOS), and not 1.10 (DOS),
which most/all DOS-oriented BBSes use.  Thus, I need to find where
I can get a version that's compatible.
 
Please email with ftp sites where I can get these.  I think it's
unzip 5.0?

-----------------------------


End of INFO-UNIX Digest
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