HDTenEightyP/NetNews huggingface dataset:
From: fitzgb@mml0.meche.rpi.edu (Brian Fitzgerald)
Newsgroups: comp.unix.wizards
Subject: Intro to comp.unix.wizards - read before posting! (weekly announcement, last change: Jul 31 10:30)
Date: 30 Aug 92 10:00:38 GMT
Expires: Tue, 29 Sep 1992 10:00:26 GMT
Followup-To: poster
Organization: Rensselaer Polytechnic Institute, Troy NY

Please take a moment to read this before posting to comp.unix.wizards
for the first time.

comp.unix.wizards is for in-depth discussion of advanced unix topics.

Elementary questions do not belong in comp.unix.wizards.  Although some
socket questions (for example) are appropriate, "How do I program with
sockets?" is not.

Crossposting to comp.unix.wizards and comp.unix.questions is
inappropriate.  Plenty of wizards read comp.unix.questions and answer
questions there.

A wizard is someone who can rewrite the entire system from scratch.  If
you are not a wizard, you are welcome to follow along the discussions
anyway.  You'll learn quite a bit about how UNIX works.  Caution: post
to wizards only if you are yourself a wizard.

For a list of answers to frequently asked questions (FAQ), please refer
to comp.unix.questions (or comp.lang.c, news.answers, etc...).  "How do
I delete a file whose name starts with a '-' ?" is an example of such a
question.  Please do not ask or answer FAQ's on the net.

Write to Unix-Wizards-Request@BRL.MIL (Subject: subscribe.  Any
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To unsubscribe from the unix-wizards mailing list, send mail to
Unix-Wizards-Request@BRL.MIL Subject: unsubscribe.  It is incorrect to
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E-mail comments about this posting are welcome.  From time to time I'll
summarize them.

Brian
--
These opinions are mine, and do not necessarily reflect those of any
academic department or computing service at Rensselaer.
Newsgroups: comp.unix.wizards
From: imp@solbourne.com (Warner Losh)
Subject: Re: A few UNIX questions
Organization: Solbourne, User Interface Group
Date: Sun, 30 Aug 1992 01:34:40 GMT

In article <1992Aug28.232720.5343@merlin.dev.cdx.mot.com>
lezz@merlin.dev.cdx.mot.com (Lezz Giles) writes: 
>But what happens if the file is more than 0x0FFF FFFF bytes long?
                                             7fff ffff
>Any unsigned 32-bit number larger than this cannot be represented
>as a signed 32-bit number

Close.  The sign bit only steals one of your bits, not 4 of them.

Warner
-- 
Warner Losh		imp@Solbourne.COM
I've almost finished my brute force solution to subtlety.
From: pnarayan@cs.tamu.edu (P S Narayan)
Newsgroups: comp.unix.wizards
Subject: Superblock question
Date: 4 Sep 1992 21:05:11 GMT
Distribution: usa
Organization: Computer Science Department, Texas A&M University

The literature on file systems (4.2 BSD) says that the cylinder block in 
every cylinder group contains a bit map of the available data blocks in that
cylinder group. Every cylinder group also contains superblock information
for reliability.The superblock already contains the list of all free data 
blocks for that file system. Is it not redundant to have free data blocks bit 
map in the cylinder blocks when it is already there in the superblocks ?
Kindly correct me.

Thanks
Narayan
pnarayan@cs.tamu.edu
Newsgroups: comp.unix.wizards
From: jdavis@bordeaux.kpno.noao.edu (Jim Davis)
Subject: Re: Questions
Followup-To: comp.sys.sun.misc
Organization: National Optical Astronomy Observatories, Tucson AZ
Date: Wed, 26 Aug 1992 21:32:34 GMT

In article <1992Aug26.195534.24066@menudo.uh.edu> cavers@menudo.uh.edu (Chris M. Cavers) writes:
>I am trying to adapt the example ram disk device driver source
>given in the Sun manual on device drivers.
>
>a) When the os requests something from the device driver, what is the
>proper sequence of actions to take if I wish to suspend the calling
>process and queue the request.  (A detailed step by step example would
>be appreciated). 
>
>b) What is in the ram.h file that is included in the example source code?
>
>Thanks in advance
>

Well, I'm not sure about a), but b) is simple enough.  When you run your
kernel config file through /etc/config, /etc/config will see the line that
says

pseudo-device 	ram

and fill in ram.h with

#define NRAM 1

Note how the body of the ram driver is surrounded by the

#if NRAM > 0
...
#endif 

block?

Followups to comp.sys.sun.misc...
-- 
Jim Davis            | "Knock it off, Uncle Owen.  Get an afterlife!"
jdavis@noao.edu      |   -- Clarissa Darling
From: alan@nabeth.enet.dec.com (Alan Rollow - Alan's Home for Wayward Tumbleweeds.)
Newsgroups: comp.unix.wizards
Subject: Re: Disk bad block
Date: 3 Sep 92 23:06:16 GMT
Reply-To: alan@nabeth.enet.dec.com (Alan Rollow - Alan's Home for Wayward Tumbleweeds.)
Distribution: usa
Organization: Digital Equipment Corporation


In article <1992Sep2.191247.1253@tamsun.tamu.edu>, pnarayan@cs.tamu.edu (P S Narayan) writes:
>
>Hello,
>Could any one tell me how does the file manager in the Unix File System
>detect a bad block and keep a track of it so that it is never allocated
>to any file. What is badness in a block ?
>I imagine the bad block list  is kept in the zeroth block of the  filesystem.
>
As Dave Olson mentioned, it depends.

Some possible answers:

1.  Some UNIX systems will expect perfect media and not cope with
    bad blocks at all.  If you happen to have an underlying I/O
    that does cope well with them this might be alright.  Unless
    the subsystem expect help from the operating system.

2.  Others acknowledge that bad blocks occur, but know they have
    I/O subsystems that will take care of them.  They are willing
    to help the I/O subsystem perform this task.

3.  Other make no assumption that the subsystem is going to do
    anything interest and take care of themselves.  The methods
    probably vary from a "bad block file" that has the bad
    blocks allocated to it, to systems that hide real disk
    under a layer that maps out the bad blocks.  All you ever
    see is the perfect surface presented by this layer.

On the nature "badness" in a block.

To various degrees the disks you're using have error detection
(and correction) codes stored with the data on the disk.  When
it reads a block it compares runs the data through whatever
firmware or hardware that calculates the error detection code
to see if they match.  If not the block is consider bad.

If the disk or controller supports error correction it will
try to fix the error.  Way down in the operating system it may
present this state as "Data corrected, but it was X badly broken".
The host may then be responsible for telling the controller what
do with the block; replace it and write the still good data back
to the new block.  The controller may decide to do this itself.
and will just tell the host "here's a good copy.  I fixed it."

Sometimes it won't be able to correct the data and still reports
a bad block.  The controller may still go off and replace the bad
block, writting the bad data to a now good block.  Unfortunately
it may not have any way to differentiate between a bad block
and a good block with known corrupt data.  What the host does
in these cases depends on how paranoid they are about data
reliability.
  
>Regards
>Narayan
>pnarayan@cs.tamu.edu
>Texas A&M University
>
>
--
Alan Rollow				alan@nabeth.cxo.dec.com
Newsgroups: comp.unix.wizards
From: milanj@sematech.org (Jon Milan)
Subject: Re: Changing "pg" options
Organization: SEMATECH Manufacturing Systems Development
Distribution: usa
Date: Wed, 26 Aug 1992 17:13:10 GMT

In article <1992Aug25.190239.19142@cbfsb.cb.att.com> rajeev@cbnewsf.cb.att.com (rajeev.dolas) writes:
>
>
>Howdy all,
>
>	I am trying to find out if there is a way of turning the "!"
>	option off from pg.  Here is something similar to what I am 
>	trying to do:
>
>	main()
>	{
>		char t[25];
>
>		strcpy(t, "pg $HOME/.profile\n");
>		system(t);
>	}
>
>	While running this program I don't want the !<command> option
>	to be available to the user.

Just reset the SHELL environment variable in your mail to "/dev/null" or
some other dummy non-shell process.

Jon
-- 
Jon Milan         jon_milan@sematech.org      |
SEMATECH Manufacturing Systems Development    |
"is was as was was when was was as is" (pmk)  |
= = = = = = = = = = = = = = = = = = = = = = = =
Newsgroups: comp.unix.wizards
From: terry@thisbe.Eng.Sandy.Novell.COM (Terry Lambert)
Subject: Re: uncompressing an incomplete tar file
Organization: Novell NPD -- Sandy, UT
Date: Wed, 2 Sep 1992 19:45:27 GMT

In article <23015@sybase.sybase.com> brijesh@tzu.sybase.com writes:
[ ... tar stuff on, but it doesn't tar off ... ]
>3) TARed it onto TK50 tapes (~150 Meg)

TK50 drives will only hold ~60 Meg.  Maybe you meant a TK70?  If not,
this could be your problem.


					Terry Lambert
					terry_lambert@gateway.novell.com
					terry@icarus.weber.edu

---
Disclaimer:  Any opinions in this posting are my own and not those of
my present or previous employers.
Newsgroups: comp.unix.wizards
From: rickert@mp.cs.niu.edu (Neil Rickert)
Subject: Re: sendmail  problem: mailhost: DATA wait (sendmail)
Organization: Northern Illinois University
Distribution: comp
Date: Sun, 30 Aug 1992 23:48:30 GMT

In article <MRD.92Aug30191004@morsel.stdavids.picker.com> mrd@morsel.stdavids.picker.com (Michael DeCorte) writes:
>
>I'm completely stumped.  I have a microvax running Mt Xinu.  I changed
>its name a few days ago and sendmail broke.  I can send local mail, I
>can receive mail, I can't send mail.  When I try it just hangs on
>the DATA part.

If you use a freeze file, I hope you rebuilt it with 'sendmail -bz' after
the name change.

One place to look is in the parsing of header addresses.  The header address
rewrites occur in the DATA phase.  If you have debugging compiled in, you
should try sending a message with the '-d21.15' flag, to see what kind of
rewriting is happening.  Expect lots of output.  Perhaps you have a
rewriting loop somewhere.
From: bill@toby.transportation.state.mn.us (Hari Seldon psycohistorian)
Newsgroups: comp.unix.wizards
Subject: Re: Info needed on UnErase utility ...
Date: 2 Sep 92 15:53:20 GMT


>The Norton Utilities for System V includes this capability for INTERACTIVE,
>SCO and AT&T V.3.2 systems and provides a very reliable and configurable 
>service for recovering deleted files.  Support for other systems (V.4,
Apple,
>IBM, HP, ...) is in limbo.

>LoneStar's ButtSaver provides a less reliable mechanism to recover VERY 
>RECENTLY deleted files on old-style (non-bitmap-freelist) file systems. 
>The LoneStar product is less costly but works on a wider range of platforms.


or you can get some free code:

unix review oct 1990 unix file recovery by lyle frost.
source is supposed to be at:

uunet!beast  or attmail!beast in /usr/spool/uucppublic/undel.cpio
66,560 bytes

no i don't have it, we've not expended any energy on it. yet.

bill pociengel
From: PATTARINI@cheers.gs.com (David Pattarini 774 2406,home 792 2419, fax 774 2626)
Newsgroups: comp.unix.wizards
Subject: subscribe
Date: 28 Aug 92 16:36:30 GMT

Please subscribe me to this list



+----------------------------------------------------------------------------+
|--------------------------------------------------------------------------- |
|----------------------                                  ------------------- |
|---------------------- David Pattarini                  ------------------- |
|----------------------    Goldman, Sachs & Co           ------------------- |
|----------------------         London Strategy Group    ------------------- |
|----------------------           Tel: London 2406       ------------------- |
|----------------------                                  ------------------- |
|----------------------           071 774 2406           ------------------- |
|--------------------------------------------------------------------------- |
+----------------------------------------------------------------------------+
Newsgroups: comp.unix.wizards
From: jeffj@krfiny.uucp (J. Jonas)
Subject: Re: A few UNIX questions
Summary: sounds like a woops to me!
Organization: Jeff's house of computer pieces
Date: Thu, 27 Aug 1992 16:22:20 GMT

>mike@BRL.MIL ( Mike Muuss) writes:
>:
>: From: Michael Panosh <mwp.michael@melpn1.prime.com> PrimeService, Australia
>:
>: > Can *anyone* tell me why the file size is a signed integer.  Surely there
>: > is no need for negative sized files!!
>:
>: Because lseek() needs to be able to return -1 on error, and not have it
>: look like a valid file offset.

>Umm, and a *signed* file size helps, does it?

The external type used for file size (as used for system calls)
and the internal one used in the on-disk inode don't have to be the same.

I agree that the type used for the return value for lseek()
needs to be signed so that errors can be returned
(0 and >0 are valid values).

But in the 'classic' S5 file system, look at ino.h
/*
 *  Inode structure as it appears on a disk block.
 */
struct  dinode
	{
	off_t   di_size;        /* number of bytes in file */

in types.h,
	typedef long        off_t;      /* ?<offset> type */

I know of no possible time a file could have a negative size.
The type should have been unsigned.
With triple indirect blocks, the file size is limited by the
highest integer you can put in a long.
Making it unsigned would double the allowable file size,
but then lseek would start returning negative values for large files.

A fine point about this variable: it's not really the file size,
it's the offset of the last valid byte.

For example:
	create a file
	lseek 1000000 bytes into the file
	write ONE byte
The di_size will be 1000000, yet only one block was allocated.
The file has a 'hole' in it (which always reads as all nulls).
The disk space consumed is one block (512, 1k, 2k, 4k or 8k),
which may be less than 'di_size'.
Even 'du' is wrong since it only rounds up 'di_size' to the next
highest block count.
The only way to truly determine the disk space a file occupies is to
count the number of non zero block addresses in the inode.
Some file systems make this distinction and maintain
both counts in the inode.
That's why SVR4 expanded stat to return a generic stat structure
with provisions for reporting file size (in blocks), block size,
and offset to last byte.
(I'm not running SVR4 so I can't elaborate on the new and improved stat).

- Jeffrey Jonas
jeffj@synsys.uucp
-- 
-- 
Jeffrey Jonas

jeffj@synsys.uucp
Newsgroups: comp.unix.wizards,comp.unix.questions,comp.windows.x
From: acourtny@unix1.tcd.ie (Antony A. Courtney)
Subject: Re: reliable signals under BSD / SVR4
Keywords: signals, reliable, software interrupts
Organization: Trinity College, Dublin
Date: Fri, 4 Sep 1992 08:55:57 GMT

In <1992Sep3.231707.17858@noao.edu> rstevens@noao.edu (W. Richard Stevens) writes:

>>Come to think of it, doesn't it make it somewhat "tricky" to use
>> async. I/O at all?

>I've yet to find a real application that actually uses BSD's SIGIO.
>Has anyone seen one?

Sure.  Back when I was at LBL, we had an animation server which I ported to X.
When you hit the "play" button on the interface, it would just render frames
as fast as it could.  I didn't want the overhead of a "check for any activity
on my UI" inside this loop, so I marked the socket connected to the X server
for asynchronous I/O.  That way it would actually stop when you hit the "stop"
button on the UI.  This is also applicable to any system which passes control
to some subroutine library for what could be "a long time" (e.g. doing a real
long image transformation of some sort).

The impression one gets from reading the docs on BSD's SIGIO is that it can
be used to write programs using interrupt-driven i/o.  IMHO, if no "real"
programs use SIGIO it shouldn't be provided.  But if it is provided, it should
work as advertised.

(begin long aside)
That said, it can be argued that any library which forces the programmer to 
relinquish the flow of control to the library is badly designed.  Obviously 
there can be only one main dispatch loop in a single-threaded program, so it is 
at best quite difficult to interwork two libraries which want to provide the 
main dispatch loop for the programmmer.  (e.g.  using an X toolkit in 
conjunction with RPC) Further, such centralized dispatch loops use an 
"event-callback" mechanism which clouds the natural control flow that 
characterises the program.  This means that every "callback" function has to 
check any data structure it operates on for consistency and validity.  For 
instance, if I have a callback for a "zoom" button in a program that manipulates
images, my callback function has to check that the image data structure is 
consistent, since it doesn't have any way of knowing whether or not the "load"
button has been pressed to load an image.  In a more conventional program, the 
flow of control is governed by the program structure, and the abstract flow
graph it defines would never let a "zoom" function be called before a "load"
function. 
(end long aside)

>	Rich Stevens  (rstevens@noao.edu)

	-antony
--
********************************************************************************
* Antony A. Courtney                              Email: acourtny@unix1.tcd.ie *
* Computer Science Department                            antony@george.lbl.gov *
* Trinity College, Dublin, Ireland                Phone: 01+353+1-607389       *
Newsgroups: comp.unix.wizards,comp.unix.questions
From: rstevens@noao.edu (W. Richard Stevens)
Subject: Re: reliable signals under BSD / SVR4
Keywords: signals, reliable, software interrupts
Organization: National Optical Astronomy Observatories, Tucson, AZ, USA
Date: Thu, 3 Sep 1992 23:17:07 GMT

>Has anyone investigated other models for signal delivery?

In the SVR4 sigaction(2) man page under SA_SIGINFO it says that the
signals are "reliably queued."  Apparently SVR4 can provide queued
signals, but someone-in-the-know told me that Sun made AT&T take this
feature out (when they were working on SVR4 together).  Perhaps POSIX.4
will have them put it back in ...

>Come to think of it, doesn't it make it somewhat "tricky" to use
> async. I/O at all?

I've yet to find a real application that actually uses BSD's SIGIO.
Has anyone seen one?

	Rich Stevens  (rstevens@noao.edu)
From: robichau@IRO.UMontreal.CA (Benoit Robichaud)
Newsgroups: comp.unix.wizards
Subject: fingering
Date: 3 Sep 92 17:40:44 GMT
Organization: Universite de Montreal


May be those are FAQ but ....

	Is there a way to know if someone is :

	- "fingering" me ?
	- trying do do "more" on one of my files (permitted or not) ?

thanks
Benoit
From: clone@alliant.snu.ac.kr
Newsgroups: comp.unix.wizards
Subject: Info needed on UnErase utility ...
Date: 28 Aug 92 05:41:30 GMT

Dear Netter ...

I have a FAQ (I believe) question about the Quick Undelete utility.
Is there anybody out there who knows and are willing to let me know
how can I get the program or more information on the utility which
will do following functions ...

*  Quick Undelete removed files on Unix platform
** Any utility doing PC-Shell like function on my Alliant or IRIS ...

Any comments would be very valuable to me .
Thanks for reading me and in advance .

Sincerely Rhee Hwan-Seok
Seoul National Univ.
e-mail : clone@alliant.snu.ac.kr
         hyunerho@krsnucc1.BITNET
From: david@cssnet.UUCP (J. David Schronce)
Newsgroups: comp.unix.msdos
Subject: Re: End-of-file
Date: 31 Aug 92 01:26:45 GMT
Organization: Computer Support Services

ggvvgg@mixcom.com (Dave Fenske) writes:

> I have heard there is a DOS utility available (somewhere) that appends
> an end-of-file (^Z) to any file that is closed without having one.
> 
> I am in urgent need of such a utility.  It would be used for properly
> terminating a plot file which is being sent across a Lan Man X network.  Whic
> plot file, BTW, never makes it because Lan Man thinks it doesn't end.
> 
> Any names, phone numbers or leads would be greatly appreciated.
> 
> DF

it seems to me that you can append a ^Z with the following:

C:\ > REM >> filename

that SHOULD do it for you, assuming that you are in a DOS environment.  
Note that this is untested and only a suggestion.  Be sure to 
experiment on COPIES of your important files.
  

---dave---
+-----------------------------------------------------------------+
|J. David Schronce     "Death Before Decaf!!"    david@cssnet.UUCP|
|Computer Support Services                            919/775-2145|
|-----------------------------------------------------------------|
|          "The opinions and the company are both mine..."        |
+-----------------------------------------------------------------+
From: philip@think.com (Philip Mucci)
Newsgroups: comp.unix.msdos
Subject: Thanks for the help...(Was: Unix/X on IBM ....)
Date: 26 Aug 1992 17:43:39 GMT
Organization: Thinking Machines Corporation, Cambridge MA, USA
NNTP-Posting-Host: lugh.think.com

	Just wanted to thank everyone for the info I received on Unix S/W.
It looks like Linux/X is my best bet.

	Regards,
		-Pjm

Newsgroups: comp.unix.msdos
From: giaahu@giau01.gia.ch (Andreas Huerzeler)
Subject: PCs connectet to UNIX
Reply-To: giaahu@giau01.gia.ch (Andreas Huerzeler)
Organization: Grapha Informatik AG
Date: Wed, 2 Sep 1992 09:49:44 GMT



Hello all,

We consider to connect our PCs to a UNIX host. Currently we 
work with DEC ULTRIX Systems, but we prefer no proprietary 
Software. We intend to store all the PC-programs and data on the 
host, thus we need the local PC-disks only for swapping. There
are no floppydrives installed on the PCs.

Which is the suitable serversoftware ?

It should be possible to maintain the PCs with a management-
software installed central on the server. The feature "PC-
remote-boot" should be given as well.

Does anybody know about an UNIX-software which fulfil all
this demands ?

Please answer by E-Mail: giaahu@gia.ch

I would greatly appreciate any information.

A. Huerzeler

-- 
NAME   Andreas Huerzeler
EMAIL  giaahu@gia.ch
SNAIL  Peyermattstr. 3, 4665 Oftringen, Switzerland
PHONE  +41-62-997281
From: rick.guthier@cccbbs.UUCP (Rick Guthier) 
Newsgroups: comp.unix.msdos
Subject: DROP
Date: 28 Aug 92 00:19:00 GMT
Distribution: world
Organization: Cincinnati Computer Connection BBS - Cincinnati, OH - 513-752-8248
Reply-To: rick.guthier@cccbbs.UUCP (Rick Guthier)
From: david@cssnet.UUCP (J. David Schronce)
Newsgroups: comp.unix.msdos
Subject: Re: X Server on PC
Date: 30 Aug 92 02:36:55 GMT
Organization: Computer Support Services

young@is.s.u-tokyo.ac.jp (liufs) writes:

> Hi!
> 
> This may be a question asked hundreds of times. I am looking for X server
> for IBM PC and compatibles. I also want to know how to run X window on
> PC, under Windows for example, and which X window product is better. Any
> information is appreciated. Please email to me at
> young@is.s.u-tokyo.ac.jp
> 
> Thank you in advance.

I HEARTILY recommend DesqView-X.  It's a VERY robust product and does 
some AMAZING things when linked to DOS Windows & UNIX machines on a 
network.
  
Disclaimer: I'm just a satisfied customer...


---dave---
+-----------------------------------------------------------------+
|J. David Schronce     "Death Before Decaf!!"    david@cssnet.UUCP|
|Computer Support Services                            919/775-2145|
|-----------------------------------------------------------------|
|          "The opinions and the company are both mine..."        |
+-----------------------------------------------------------------+
Newsgroups: comp.unix.msdos
From: zimmerms@Informatik.TU-Muenchen.DE (Stephan Zimmermann)
Subject: Yacc, Lex, Bison for MSDOS ???
Originator: zimmerms@hphalle7b.informatik.tu-muenchen.de
Organization: Technische Universitaet Muenchen, Germany
Date: Tue, 1 Sep 1992 12:35:01 GMT


Keywords: 

Does anybody know if YACC, BISON or LEX is available for MSDOS ?
I need it desperatly !

Thanks in advance Stephan.