Linux-Development-Sys Digest #740, Volume #7 Tue, 4 Apr 00 21:13:14 EDT
Contents:
Re: Bootdisks, rdev, and root filesystems...aargh! (Neil Koozer)
Re: To core or not to core - You tell me (Erik Max Francis)
Re: struct passwd * (Bryan Hackney)
Re: To core or not to core - You tell me ("-hs-")
Re: To core or not to core - You tell me ("Lou Zher")
Re: To core or not to core - You tell me (Barry Margolin)
Re: Linx-Fonts (Juergen Heinzl)
Re: How to decide a file is newly created? (Juergen Heinzl)
Re: Parallel port programming... pins 12 and 13 not working (bill davidsen)
Re: struct passwd * ([EMAIL PROTECTED])
Re: struct passwd * (bill davidsen)
system calls table: where is it? ([EMAIL PROTECTED])
no swap ([EMAIL PROTECTED])
fetchmail timeout ("News Clear")
Re: To core or not to core - You tell me (Warren Young)
Re: Dynamic class instanciation using modules (David Wragg)
Re: To core or not to core - You tell me (Johan Kullstam)
Re: Linux and Posix AIO (Warren Young)
Re: To core or not to core - You tell me (Alan Coopersmith)
Re: How compatible is Linux with .. Linux (Christopher Browne)
Re: To core or not to core - You tell me (David Williams)
Re: To core or not to core - You tell me (mike burrell)
----------------------------------------------------------------------------
From: Neil Koozer <[EMAIL PROTECTED]>
Crossposted-To: alt.os.linux,comp.os.linux.misc
Subject: Re: Bootdisks, rdev, and root filesystems...aargh!
Date: Tue, 04 Apr 2000 13:16:55 -0700
Don Werve wrote:
>
> Ok. After reading the Bootdisk-HOWTO and rdev manpages, I decided to
> start on the path to true geekdom and make my own Linux bootdisk, so
> that I could manually build a Linux system from the ground up on one of
> my many spare computers. I've been using Linux for about two years now,
> but what better way to learn about the guts of the OS than to manually
> build a full system?
>
> Anyways, I made a root filesystem that compressed takes up 900K, and
> have a 460K kernel. I used dd to copy the kernel image to the disk, and
> then used `rdev /dev/fd0 /dev/fd0 ; rdev -R /dev/fd0 0` to set the disk
> as it's own root device. How do you tell the kernel where to look for a
> compressed root filesystem, so that it can be uncompressed into a
> ramdisk and booted...?
>
> Ideas? Sorry about the cross-post, but it seemed applicable to each
> newsgroup posted to. Please reply via E-Mail, to hari AT iveleague.org
>
> Thanks in advance! :)
This is in the "Setting the ramdisk word" section of the Bootdisk-HOWTO.
For a 2-disk boot/root pair, you would use
rdev -r /dev/fd0 49152
49152 is 0xc000
For a single boot/root disk you would use 0x4000 + the offset to the
start of the compressed ramdisk image. The offset is the number of 1k
blocks.
Neil
------------------------------
From: Erik Max Francis <[EMAIL PROTECTED]>
Crossposted-To: comp.lang.c,comp.unix.solaris,comp.lang.c++,comp.unix.programmer
Subject: Re: To core or not to core - You tell me
Date: Tue, 04 Apr 2000 14:15:40 -0700
John Gluck wrote:
> The pointer that is passed to printf will be NULL. Some
> implementations
> of printf will check the parameters passed. If it finds that one of
> the
> parameters (a pointer) is NULL, rather than try to print what NULL
> points to, it will simply print (null) in the output where the value
> pointed to would otherwise go.
>
> Taking the example above, the line printf("%d\n", ptr->a);
> would print the same result as if it had been coded
> printf("(null)\n");
>
> Hope that clears it up.
I find that very hard to believe. The dereferencing of the null pointer
happens before printf is even called, not to mention the fact that an
int is being passed to printf, not a pointer, so how is printf supposed
to magically know to print "(null)" instead of what's being passed?
--
Erik Max Francis | email [EMAIL PROTECTED] | icq 16063900
Alcyone Systems | web http://www.alcyone.com/max/ | q3a Product
San Jose, CA | languages en, eo | icbm 37 20 07 N 121 53 38 W
USA | 968.994 Ms p.L. | 272 days left | &tSftDotIotE
------------------------------
From: Bryan Hackney <[EMAIL PROTECTED]>
Subject: Re: struct passwd *
Date: Tue, 04 Apr 2000 16:22:17 -0500
[EMAIL PROTECTED] wrote:
>
[...]
>
> if (myp != (struct passwd *) NULL)
> {
> free(myp);
> }
[...]
The pointer appears to not be coming from the free store. Have to go
to the library source for the real scoop.
--
Bryan Hackney / BHC / [EMAIL PROTECTED]
http://www.FreeClassAds.com/
http://bhconsult.com/
http://bhconsult.com/bh/pgp.key
------------------------------
From: "-hs-" <[EMAIL PROTECTED]>
Crossposted-To: comp.lang.c,comp.unix.solaris,comp.lang.c++,comp.unix.programmer
Subject: Re: To core or not to core - You tell me
Date: Tue, 4 Apr 2000 23:25:01 +0200
Juergen Heinzl a �crit dans le message ...
[...] too...
>
>You should think of what the compiler is, probably, going to
>generate:
>
>ptr is NULL, so the base address is 0x00000000. a is an integer and
Wow ! In your machine perhaps, but the C-language does not guarantee a NULL
pointer to be at address 0.
--
-hs- "Stove"
CLC-FAQ: http://www.eskimo.com/~scs/C-faq/top.html
ISO-C Library: http://www.dinkum.com/htm_cl
"It's specified. But anyone who writes code like that should be
transmogrified into earthworms and fed to ducks." -- Chris Dollin CLC
------------------------------
From: "Lou Zher" <[EMAIL PROTECTED]>
Crossposted-To: comp.lang.c,comp.unix.solaris,comp.lang.c++,comp.unix.programmer
Subject: Re: To core or not to core - You tell me
Date: Tue, 04 Apr 2000 21:34:11 GMT
John Gluck wrote:
[snip]
>Taking the example above, the line printf("%d\n", ptr->a);
>would print the same result as if it had been coded
>printf("(null)\n");
In that example, ptr->a would be evaluated prior to calling printf. The
number itself, not the pointer, would be pushed onto the stack. printf("%p",
ptr) could know to print "(null)", but my quick test shows it doesn't.
-LZ
------------------------------
From: Barry Margolin <[EMAIL PROTECTED]>
Crossposted-To: comp.lang.c,comp.unix.solaris,comp.lang.c++,comp.unix.programmer
Subject: Re: To core or not to core - You tell me
Date: Tue, 04 Apr 2000 21:49:09 GMT
In article <8cdmjd$15fv$[EMAIL PROTECTED]>,
-hs- <[EMAIL PROTECTED]> wrote:
>Juergen Heinzl a �crit dans le message ...
>[...] too...
>>
>>You should think of what the compiler is, probably, going to
>>generate:
>>
>>ptr is NULL, so the base address is 0x00000000. a is an integer and
>
>
>Wow ! In your machine perhaps, but the C-language does not guarantee a NULL
>pointer to be at address 0.
He *did* say "probably". The C language doesn't guarantee it, but most
implementations work that way anyway.
Furthermore, the original poster asked what would happen in specific
systems. I'll bet that all of them use null pointers with the above
representation.
--
Barry Margolin, [EMAIL PROTECTED]
GTE Internetworking, Powered by BBN, Burlington, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.
------------------------------
From: [EMAIL PROTECTED] (Juergen Heinzl)
Subject: Re: Linx-Fonts
Date: Tue, 04 Apr 2000 22:00:09 GMT
In article <[EMAIL PROTECTED]>, Michael Schoettner wrote:
>Hi all,
>
>are there any documents or source texts about linux fonts available?
>I'm interested in algorithms for scalable fonts (like the MS
>True-Type-Fonts).
>A short e-mail would be great.
There is no such thing as Linux fonts, so general notations apply.
If it comes to TTF, then this issue has been discussed quite often
but you might look ...
http://www.fokus.gmd.de/linux/lg/issue28/ayers1.html
... here and ...
http://www.dcs.ed.ac.uk/home/jec/programs/xfsft/
... for instance. Mind esp. free fonts are at times of low
quality and may not work on *nix systems at all, TT fonts, that
is. Even MS fonts are not always error free, but still they should
not cause much of an headache.
There is a freetype library available but the last time I had had
a look there were still some open licence issues.
Cheers,
Juergen
--
\ Real name : J�rgen Heinzl \ no flames /
\ EMail Private : [EMAIL PROTECTED] \ send money instead /
------------------------------
From: [EMAIL PROTECTED] (Juergen Heinzl)
Subject: Re: How to decide a file is newly created?
Date: Tue, 04 Apr 2000 22:00:10 GMT
In article <8caicc$gju$[EMAIL PROTECTED]>, Weiguang Shi wrote:
>Hi, there:
> Could anyone please tell me how to decide inside the system calls, say
>write, the current file is a newly-created one rather than one created
>before and opened again for WR or RDWR ?
open it using O_CREAT | O_EXCL and see man 2 open for some caveats
in connection with files residing on a NFS volume.
Cheers,
Juergen
--
\ Real name : J�rgen Heinzl \ no flames /
\ EMail Private : [EMAIL PROTECTED] \ send money instead /
------------------------------
From: [EMAIL PROTECTED] (bill davidsen)
Subject: Re: Parallel port programming... pins 12 and 13 not working
Date: 4 Apr 2000 22:02:33 GMT
In article <8ca68v$tmf$[EMAIL PROTECTED]>,
Stuart Hall <[EMAIL PROTECTED]> wrote:
| Pins 12 and 13 are for Paper Empty and Select. Is my parallel port
| bad? Or is it possible that pins 12 and 13 are not used in the IBM
| parallel port standard way on a GW computer?
Of course. But before you decide that, be sure the port is a standard
port, not using any pins to control a fifo, dma, sense moon phase,
whatever. These new EPP and ECP (etc) ports are not your mother's
parallel port, and may be the problem.
| Any thoughts on using COM2 w/ a female-female 25 pin connector?
Just remember that RS-232 is +/-12v, *NOT* 0-5v as so bozo
implementations provide. Other than that, I see no reason why you
couldn't do it.
--
bill davidsen <[EMAIL PROTECTED]> CTO, TMR Associates, Inc
"Doing interesting things with little computers since 1979"(tm)
The hardest test of maturity is knowing the difference between
resisting temptation and missing a once-in-a-lifetime opportunity.
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: struct passwd *
Date: Tue, 04 Apr 2000 22:08:12 GMT
[EMAIL PROTECTED] wrote:
Curiously, I compiled it up and it worked.
--
Best regards,
Stephen Jenuth
([EMAIL PROTECTED])
Quidquid latine dictum sit, altum viditur.
------------------------------
From: [EMAIL PROTECTED] (bill davidsen)
Subject: Re: struct passwd *
Date: 4 Apr 2000 22:12:07 GMT
In article <8cdkj5$pb0$[EMAIL PROTECTED]>, <[EMAIL PROTECTED]> wrote:
| ok why does this program result in a SEGV? On solaris the exact code
| does not. Am I missing something, like the result is protected memory
| and when you try to free it, it will not let you? Any assistance would
| be appreciated!
I'm suspicious that even though the man page under ERRORS says "ENOMEM
Insufficient memory to allocate passwd structure," I am suspicious that
the pointer may be to a static buffer rather than a malloced object. You
might malloc a small buffer and print the address (%p), then the pointer
returned before you try to free that. You might want fflush() in there.
The Linux man page doesn't really say the buffer is dynamically
allocated, the error certainly implies that, and you are right in
free()ing it.
Someone have the source for glibc handy? I don't, and I'm not going to
go grab it.
You might also look at the code very hard to be sure that you don't
change the pointer, assuming that there is more code than you showed.
Pardon if there's not.
--
bill davidsen <[EMAIL PROTECTED]> CTO, TMR Associates, Inc
"Doing interesting things with little computers since 1979"(tm)
The hardest test of maturity is knowing the difference between
resisting temptation and missing a once-in-a-lifetime opportunity.
------------------------------
From: [EMAIL PROTECTED]
Subject: system calls table: where is it?
Date: Tue, 04 Apr 2000 22:09:07 GMT
Please, can somebody point me to this piece of information (source and
docs)?
Thank you in advance.
-ea-
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
From: [EMAIL PROTECTED]
Subject: no swap
Date: Tue, 04 Apr 2000 23:33:03 GMT
I'm preparing to set up a Linux system without swap space. I know how to
do this, so it's not a question for c.o.l.setup. It was running just fine
with 128meg RAM and 160meg swap and rarely got about about 8meg (as reported
by "top") into the swap space. I've now increased RAM to 384meg and I want
to disable swap altogether. But I notice that it has swapped about 2meg
anyway, despite RAM usage not being above 100meg yet. What I would like
to know is why, and what the impact will be if there is no swap space at
all (besides the fact that no confidential data will be on disk that was
not written explicitely).
--
| Phil Howard - KA9WGN | My current boycotts: Amazon.Com, DVDs, Mattel, Sony
| [EMAIL PROTECTED] +----------------------------------------------------
| Dallas - Texas - USA | My current websites: linuxhomepage.com, ham.org
------------------------------
From: "News Clear" <[EMAIL PROTECTED]>
Crossposted-To:
ahn.tech.linux,alt.os.linux.dial-up,comp.os.linux.development.apps,comp.os.linux.misc,cz.comp.linux
Subject: fetchmail timeout
Date: Wed, 5 Apr 2000 12:18:18 +1200
I have a problem with fetchmail. My linux mail server dials the ISP every
half hour and delivers/collects the mail. That works fine most of the time
but every now and then it gets stuck not being able to retrieve the mail.
The example below shows the log of the event.
The collection starts but the ISP comes back with a timeout on the deleting
the first message. The ISP can't help of course, they don't deal with any
non windows systems.
I have the impression that my end times out due to system overload at my
machine (486/100MHz) because the inhouse mail clients are querying their
mailbox quite frequently.
Is that possible or is it really the problem of the ISP.
Has anyone seen that kind of problem before?
Regards
Andreas Hagele
section from /var/log/messages
Apr 4 16:01:30 Axis fetchmail[811]: POP3> STAT
Apr 4 16:01:31 Axis fetchmail[811]: POP3< +OK 49 4390377
Apr 4 16:01:31 Axis fetchmail[811]: POP3> LAST
Apr 4 16:01:32 Axis fetchmail[811]: POP3< +OK 0 is the last read message.
Apr 4 16:01:32 Axis fetchmail[811]: 49 messages for fortuneg at
pop3.wave.co.nz (4390377 octets).
Apr 4 16:01:32 Axis fetchmail[811]: POP3> LIST^M
Apr 4 16:01:32 Axis fetchmail[811]: POP3< +OK 49 messages (4390377 octets)
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 1 4390
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 2 1899
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 3 4786
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 4 5796
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 5 2164
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 6 6318
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 7 486474
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 8 7191
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 9 1692
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 10 1660
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 11 1357
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 12 1626
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 13 141576
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 14 1313477
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 15 9026
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 16 33356
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 17 971
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 18 106181
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 19 85391
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 20 3745
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 21 4733
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 22 2468
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 23 1937
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 24 2426
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 25 2041
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 26 2506
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 27 2381
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 28 5338
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 29 2027
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 30 4242
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 31 1972
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 32 2703
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 33 1988
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 34 1794
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 35 935682
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 36 8644
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 37 6064
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 38 157361
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 39 485022
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 40 1001
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 41 2508
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 42 1613
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 43 1280
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 44 3336
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 45 3576
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 46 521178
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 47 1084
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 48 3381
Apr 4 16:01:33 Axis fetchmail[811]: POP3< 49 1015
Apr 4 16:01:33 Axis fetchmail[811]: POP3< .
Apr 4 16:01:33 Axis fetchmail[811]: POP3> TOP 1 99999999
Apr 4 16:01:34 Axis fetchmail[811]: POP3< +OK 4390 octets
Apr 4 16:01:34 Axis fetchmail[811]: reading message 1 of 49 (4390 octets)
Apr 4 16:02:11 Axis in.pop3d[813]: connect from 192.168.1.20
Apr 4 16:02:32 Axis in.pop3d[813]: Servicing request for marja
Apr 4 16:03:18 Axis in.pop3d[816]: connect from 192.168.1.11
Apr 4 16:03:19 Axis in.pop3d[816]: Servicing request for andreas
Apr 4 16:03:23 Axis in.pop3d[817]: connect from 192.168.1.15
Apr 4 16:03:24 Axis in.pop3d[817]: Servicing request for jurgen
Apr 4 16:03:34 Axis in.pop3d[818]: connect from 192.168.1.20
Apr 4 16:03:35 Axis in.pop3d[818]: Servicing request for marja
Apr 4 16:04:37 Axis in.pop3d[819]: connect from 192.168.1.20
Apr 4 16:04:38 Axis in.pop3d[819]: Servicing request for marja
Apr 4 16:05:25 Axis in.pop3d[822]: connect from 192.168.1.15
Apr 4 16:05:27 Axis in.pop3d[822]: Servicing request for jurgen
Apr 4 16:05:34 Axis in.pop3d[823]: connect from 192.168.1.21
Apr 4 16:05:36 Axis in.pop3d[823]: Servicing request for tony
Apr 4 16:05:39 Axis in.pop3d[824]: connect from 192.168.1.20
Apr 4 16:05:40 Axis in.pop3d[824]: Servicing request for marja
Apr 4 16:06:41 Axis in.pop3d[825]: connect from 192.168.1.20
Apr 4 16:06:43 Axis in.pop3d[825]: Servicing request for marja
Apr 4 16:06:51 Axis in.pop3d[826]: connect from 192.168.1.21
Apr 4 16:06:52 Axis in.pop3d[826]: Servicing request for halina
Apr 4 16:07:28 Axis in.pop3d[827]: connect from 192.168.1.15
Apr 4 16:07:29 Axis in.pop3d[827]: Servicing request for jurgen
Apr 4 16:07:44 Axis in.pop3d[828]: connect from 192.168.1.20
Apr 4 16:07:45 Axis in.pop3d[828]: Servicing request for marja
Apr 4 16:07:50 Axis identd[831]: Connection from localhost
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 220 Axis.fortunecorp.co.nz ESMTP
Sendmail 8.9.1/8.8.6; Tue, 4 Apr 2000 16:07:51 +1200
Apr 4 16:07:51 Axis fetchmail[811]: SMTP> EHLO localhost
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250-Axis.fortunecorp.co.nz Hello
root@localhost [127.0.0.1], pleased to meet you
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250-EXPN
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250-VERB
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250-8BITMIME
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250-SIZE
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250-DSN
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250-ONEX
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250-ETRN
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250-XUSR
Apr 4 16:07:51 Axis fetchmail[811]: SMTP< 250 HELP
.
.
Apr 4 16:07:52 Axis fetchmail[811]: SMTP> DATA
Apr 4 16:07:52 Axis fetchmail[811]: SMTP< 354 Enter mail, end with "." on a
line by itself
Apr 4 16:07:52 Axis fetchmail[811]: SMTP>. (EOM)
Apr 4 16:07:56 Axis fetchmail[811]: SMTP< 250 QAA00832 Message accepted for
delivery
Apr 4 16:07:56 Axis fetchmail[811]: flushed
Apr 4 16:07:56 Axis fetchmail[811]: POP3> DELE 1^M
==> here
Apr 4 16:07:56 Axis fetchmail[811]: POP3< -ERR POP timeout
Apr 4 16:07:56 Axis fetchmail[811]: POP3> QUIT^M
Apr 4 16:07:56 Axis fetchmail[811]: POP3< +OK Pop server at mail.wave.co.nz
signing off.
Apr 4 16:07:56 Axis fetchmail[811]: Query status=4
Apr 4 16:07:56 Axis fetchmail[811]: SMTP> QUIT
Apr 4 16:07:56 Axis fetchmail[811]: SMTP< 221 Axis.fortunecorp.co.nz
closing connection
section from /var/log/syslog
Apr 4 16:07:56 Axis fetchmail[811]: POP timeout
Apr 4 16:07:56 Axis fetchmail[811]: client/server protocol error while
fetching from pop3.wave.co.nz
Apr 4 16:23:45 Axis fetchmail[906]: POP timeout
Apr 4 16:23:45 Axis fetchmail[906]: client/server protocol error while
fetching from pop3.wave.co.nz
------------------------------
Date: Tue, 04 Apr 2000 18:20:10 -0600
From: Warren Young <[EMAIL PROTECTED]>
Crossposted-To: comp.lang.c,comp.unix.solaris,comp.lang.c++,comp.unix.programmer
Subject: Re: To core or not to core - You tell me
Phil Edwards wrote:
>
> (all schools are always strapped for diskspace :-). They figure, if you
> need a core file, you can re-enable it yourself.
Not on any system I've ever used. ulimit, at least, cannot _raise_
limits, it can only lower them. (For regular users only, of course.
Root can raise any limit up to the kernel's hard limit.) Typically such
policy goes in /etc/profile, which users can't change. Sure, you could
change each user's ~/.profile instead, (or /etc/skel/profile) but it's
not done much.
--
= Warren -- See the *ix pages at http://www.cyberport.com/~tangent/ix/
=
= ICBM Address: 36.8274040 N, 108.0204086 W, alt. 1714m
------------------------------
From: David Wragg <[EMAIL PROTECTED]>
Subject: Re: Dynamic class instanciation using modules
Date: 03 Apr 2000 18:20:26 +0000
Thomas Lefort <[EMAIL PROTECTED]> writes:
> - It appears that the usual shared library system can't do the job.
> Indeed - as far as I understood it - it requires knowledge of the
> library name at build time, and does not support simultaneous equivalent
> libraries.
man dlopen
------------------------------
Crossposted-To: comp.lang.c,comp.unix.solaris,comp.lang.c++,comp.unix.programmer
Subject: Re: To core or not to core - You tell me
From: Johan Kullstam <[EMAIL PROTECTED]>
Date: Wed, 05 Apr 2000 00:33:46 GMT
Ron Natalie <[EMAIL PROTECTED]> writes:
> John Gluck wrote:
> >
> > > > > ptr = NULL;
> > > > >
> > > > > printf("%d\n", ptr->a);
>
> >
> > The pointer that is passed to printf will be NULL.
>
> No pointer, null or otherwise, is passed to printf.
to be worthlessy pedantic, yes there is. the pointer to the string
"%d\n" is being passed.
--
J o h a n K u l l s t a m
[[EMAIL PROTECTED]]
Don't Fear the Penguin!
------------------------------
Date: Tue, 04 Apr 2000 18:34:26 -0600
From: Warren Young <[EMAIL PROTECTED]>
Subject: Re: Linux and Posix AIO
Fabrice Peix wrote:
>
> Yes SGI create a patch for real efficient aio,but the glibc 2.1 offers
> all or subset (?) of the primitives
> of POSIX 4. I don't know if the implementation is very efficient but i
> know is usable.
The whole point of AIO is that it be more efficient than standard
Berkeley socket I/O. How can a userland implementation built on top of
sockets be more efficient than sockets themselves, which have direct
kernel support?
Glibc AIO exists only to allow you to port programs written with AIO to
Linux. One day Linux will have official kernel support for it, but
until that day, it's not very useful to write AIO programs for Linux.
--
= Warren -- See the *ix pages at http://www.cyberport.com/~tangent/ix/
=
= ICBM Address: 36.8274040 N, 108.0204086 W, alt. 1714m
------------------------------
From: [EMAIL PROTECTED] (Alan Coopersmith)
Crossposted-To: comp.lang.c,comp.unix.solaris,comp.lang.c++,comp.unix.programmer
Subject: Re: To core or not to core - You tell me
Date: 5 Apr 2000 00:39:16 GMT
Warren Young <[EMAIL PROTECTED]> wrote:
>Phil Edwards wrote:
>>
>> (all schools are always strapped for diskspace :-). They figure, if you
>> need a core file, you can re-enable it yourself.
>
>Not on any system I've ever used. ulimit, at least, cannot _raise_
>limits, it can only lower them. (For regular users only, of course.
Really? On every system I've used, regular users can raise their soft
limits up to the hard limit, which is why we usually set the softlimit
to 0 for cores, but leave the hardlimit unlimited so the users can turn
them back on when they want to debug.
--
________________________________________________________________________
Alan Coopersmith [EMAIL PROTECTED]
Univ. of California at Berkeley http://soar.Berkeley.EDU/~alanc/
aka: alanc@{CSUA,OCF,CS,BMRC,EECS,ucsee.eecs,cory.eecs}.Berkeley.EDU
------------------------------
From: [EMAIL PROTECTED] (Christopher Browne)
Crossposted-To: comp.os.linux.development.apps
Subject: Re: How compatible is Linux with .. Linux
Reply-To: [EMAIL PROTECTED]
Date: Wed, 05 Apr 2000 00:42:40 GMT
Centuries ago, Nostradamus foresaw a time when Peter T. Breuer would
say:
>OK, what IS the difference between VMS and MVS, then! Apart from the
>first letter (of their manufacturer).
In keeping with the level of friendliness being displayed thus far...
What kind of an ignoramus needs to ask the difference between VMS and
MVS?
After all, there are FAQs out there, and someone who is reasonably
literate at using the web should *surely* be able to do a _modicum_ of
research.
--
"In other words -- and this is the rock solid principle on which the
whole of the Corporation's Galaxy-wide success is founded -- their
fundamental design flaws are completely hidden by their superficial
design flaws." -- HHGTG
[EMAIL PROTECTED] <http://www.hex.net/~cbbrowne/lsf.html>
------------------------------
From: David Williams <[EMAIL PROTECTED]>
Crossposted-To: comp.lang.c,comp.unix.solaris,comp.lang.c++,comp.unix.programmer
Subject: Re: To core or not to core - You tell me
Date: Wed, 5 Apr 2000 00:32:37 +0100
In article <8cdmjd$15fv$[EMAIL PROTECTED]>, -hs-
<[EMAIL PROTECTED]> writes
>Juergen Heinzl a �crit dans le message ...
>[...] too...
>>
>>You should think of what the compiler is, probably, going to
>>generate:
>>
>>ptr is NULL, so the base address is 0x00000000. a is an integer and
>
>
>Wow ! In your machine perhaps, but the C-language does not guarantee a NULL
>pointer to be at address 0.
>
The C Programming Language Second Edition
Brian W. Kernigan
Dennis Ritchie
ISBN 0-13-110362-8
Page 102 Half way down...
"Pointers and integers are not interchangeable. Zero is the sole
exception: the constant zero may be assigned to a pointer, and a
pointer may be compared with the constant 0. The symbolic constant
NULL is often used in place of zero, as a mnemonic to indicate more
clearly that this is a special value for a pointer. NULL is defined
in <stdio.h>"
?? Is NULL==0?? This says that it often is...
Further up on the same page is...
"If not, alloc must return some signal that no space is left. C
guarantees that zero is never a valid address for data.."
!!!!! C guarantees it! From Kernigan and Ritchie the inventors of the
language!!
Further on in the book on page 198 in Appendix A which is the draft
standard submitted to the ANSI committee (BUT NOT NECCESSARILY THE
APPROVED ANSI standard) we have
"An integral constant expression with value 0, or such an expression
cast to type void *, may be converted, by a cast, by assignment, or
by comparison, to a pointer of any type. This produces a null pointer
that is equal to another null pointer of the same type, but unequal
to any pointer to a function or object"
This means that
a) 0 == NULL (an integral constant expression with value 0...
converted by comparsion...this produces a null pointer..)
^^^^^^^^^^^^^^^^^^^^^^^
??? are they the same or not?? NB A conversion could be taking
place implying that they are not.
b) A null pointer is not equal to any pointer to an object. Hence
deferencing a null pointer to get an object is not valid here!!
Phew...Thoughts???
>--
>-hs- "Stove"
>CLC-FAQ: http://www.eskimo.com/~scs/C-faq/top.html
>ISO-C Library: http://www.dinkum.com/htm_cl
>"It's specified. But anyone who writes code like that should be
>transmogrified into earthworms and fed to ducks." -- Chris Dollin CLC
>
>
>
--
David Williams
------------------------------
From: mike burrell <[EMAIL PROTECTED]>
Subject: Re: To core or not to core - You tell me
Crossposted-To: comp.lang.c,comp.unix.solaris,comp.lang.c++,comp.unix.programmer
Date: Wed, 05 Apr 2000 00:58:22 GMT
In comp.lang.c Warren Young <[EMAIL PROTECTED]> wrote:
> Phil Edwards wrote:
>> (all schools are always strapped for diskspace :-). They figure, if you
>> need a core file, you can re-enable it yourself.
> Not on any system I've ever used. ulimit, at least, cannot _raise_
> limits, it can only lower them. (For regular users only, of course.
> Root can raise any limit up to the kernel's hard limit.)
actually, not quite true. i 'ulimit -c unlimited' as luser regularly (my
core limit is 0 by default).
--
/"\ m i k e b u r r e l l
\ / ASCII RIBBON CAMPAIGN [EMAIL PROTECTED]
X AGAINST HTML MAIL http://mikpos.dyndns.org
/ \
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