Linux-Misc Digest #41, Volume #26 Sun, 15 Oct 00 16:13:01 EDT
Contents:
rcp between Linux and sco unix ("Frank Cheng")
Re: How can one app crashing bring down whole system? ("Julian Francis")
Re: What is a system map, part 2? (Jean-David Beyer)
Re: Microsoft's Anti Linux Page (Andres Soolo)
Re: What is a good graphical mail client? (ray)
Re: IPChains and Cable Modems - Fequently loosing connectivity to the Internet
(Giuseppi Tubiere)
Where do "Programs" go? ("Lamar Thomas")
How to execute a program at startup? (=?iso-8859-1?Q?St=E9phane?= K.)
Warning: Setting Locale Failed (Bryan Robinson)
Re: Linux Chat Server (Andres Soolo)
Re: Where do "Programs" go? ("J.Smith")
XFree 4.0 (David Mehringer)
Re: What is a system map, part 2? ("J.Smith")
Re: [Help Me] UDP Network Programming (Andres Soolo)
----------------------------------------------------------------------------
From: "Frank Cheng" <[EMAIL PROTECTED]>
Subject: rcp between Linux and sco unix
Date: Sun, 15 Oct 2000 18:11:29 GMT
one sco box running OSR505 with all the minimum patches installed.
one linux box running Redhat6.2
problems occurs when I do rcp between the two boxes. The message is
"Permission Denied". But
1, I run the command as root
2, both machine has entry of the others hostname in /etc/hosts.equiv
I dig in and find the Linux use "kerrobes authentication" when using
rsh,rlogin,etc. But it still say in man page that if this auth method fails,
the generic unix way works. But it does not work between sco box and linux
box.
Is there any way to turn off this auth method? or is there any way to
configure this method to let such command as rcp work between linux and sco
osr505?
TIA.
Frank Cheng
------------------------------
From: "Julian Francis" <[EMAIL PROTECTED]>
Subject: Re: How can one app crashing bring down whole system?
Date: Sun, 15 Oct 2000 19:26:36 +0100
Darren,
>From memory it is quite easy for an X window program to lock up the X
server, and effectively prevent you from using the computer.
All the program needs to do is execute:
XGrabServer(display)
After this no other programs can use the X server (and are therefore
effectively frozen) until the same program executes XUnGrabServer.
Obviously it is dubious practice for programmers to use this technique, and
happily it isn't widely used in programs. However, I believe it is used
internally in the Motif toolkit for the bit that handles drag and drop
functionality.
So for example I think this C fragment should lock up your computer quite
nicely:
XGrabServer(display)
for ( ; ; ) {}
I've been bitten by this several times when debugging the drag and drop
functionality of an application. The problem is that if a breakpoint is set
after this instruction has been executed, it will try to talk to the
debugger, but unfortunately the debugger itself is unable to communicate
with the X server as a result of this command!
Luckily it doesn't happen very often.
I can't say for sure if this is your problem. If you were very keen to find
out I think there are programs which monitor all X protocol requests, and
you could use this to see if it has just executed this X instruction before
freezing (obviously the snooper would have to save the information to a file
and not try to draw it on the screen!)
The kernel itself of course should still be running. So if you can login
externally via telnet then that would be one way of dealing with this
situation without rebooting the machine. I can't remember if you have to
kill the X server, or if it's sufficient just to kill the offending program
(but it's worth a go).
Hope this is helpful.
Julian.
"D. D. Brierton" <[EMAIL PROTECTED]> wrote in message
news:8s9jaf$iak$[EMAIL PROTECTED]...
> One of Linux's (and Unix's) strengths is supposed to be the way in which
> each process runs in its own protected mode or space (excuse my
> ignorance of the precise techical terminology). It is often touted that
> unlike in other well-known operating systems one application crashing
> cannot bring the whole system down with it.
>
> On the whole my experince has borne this out. I have many experimental,
> alpha, and beta pieces of software installed, which often crash, or
> hang, or just vanish inexplicably, whilst everything else carries on as
> if nothing has happened.
>
> However, both Netscape and Mozilla have managed to do what supposedly
> can't be done. Admittedly, Netscape hasn't done it in some time, but
> when I was running an earlier version of Mandrake and an earlier
> incarnation of Netscape 4.7x the latter would sometimes lock up the
> whole X session so tightly that I couldn't even ctrl-alt-F1 to the
> console, or ctrl-alt-backspace to kill the X session, requiring a hard
> reboot.
>
> Yesterday I installed Mozilla M18 and PSM, the personal security
> manager. Now if I click on Tasks -> Privacy and Security -> Security
> Manager the whole X session locks up. I can ctrl-alt-F1 to the console,
> and from there if I "killall mozilla-bin" then the whole X session
> crashes, and the console becomes unusable while gdm constantly tries to
> restart and fails. Eventually a hard reboot is again required.
>
> My question is not about Netscape or Mozilla---I'll post something about
> Mozilla's above behaviour to one of the mozilla groups---but about linux
> itself. I thought that this simply wasn't meant to be possible, given
> the way applications were handled by the operating system.
>
> So, are we guilty of hyping linux's stability into the realms of
> fiction? How can an app effectively bring down the system?
>
> Best,
>
> Darren
>
> --
> ======================================================================
> D. D. Brierton Department of Philosophy, University of Edinburgh
> [EMAIL PROTECTED] http://www.cogsci.ed.ac.uk/~ddb
> ======================================================================
------------------------------
From: Jean-David Beyer <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.development
Subject: Re: What is a system map, part 2?
Date: Sun, 15 Oct 2000 14:36:52 -0400
"J.Smith" wrote:
> Oh boy, here we go again... :)
The reason we go here again is because it seems to me that there is no
justification for the symbolic link "System.map". If you have only one kernel
in /boot, you could do that, but since most of us have more than one kernel
around (I have both smp and up kernels, both current and old, and some may have
new or test ones as well, it is essentially useless to have that pointer. In my
case, there is only a 25% chance that it would be pointing in the right place,
presuming (falsely) that I boot each with equal probability.
My distribution seems to come with the smp version as the standard thing to
boot, but the links all point to the up versions of the files. Is my
distribution wrong and I chould change the symbolic links? Or does it not
matter because the symbolic links are not used? I have noticed no symptoms;
could someone suggest the symptoms I would get with the symbolic links pointing
to the wrong files?
These files are pretty different:
205841 Aug 26 1999 System.map-2.2.12-0.1
216825 Aug 26 1999 System.map-2.2.12-0.1smp
203421 May 31 12:42 System.map-2.2.14-5.0.14c
214729 May 31 12:32 System.map-2.2.14-5.0.14csmp
At least, I assume that since their sizes are different that their contents
are different as well.
> For the viewers that have just tuned in, there was a tread on
> comp.os.linux.misc not so long ago that discussed the need for and use of
> the /boot/System.map file. There also seemed to be some confusion about how
> to handle 2 different kernel's in /boot, and the two different
> /boot/System.map files that go with it.
>
> Although there was no conclusive evidence, the current status seems to be as
> such:
>
> System.map is a "map" of your kernel. It contains info about the entry
> points of the functions you compiled into your kernel, and de-bug
> information. The kernel itself knows the addresses and entry-points, but
> that file is needed for some programs which need info about kernel entry
> points. These programs are klogd(8), ksymoops(8), depmod(8), and the procps
> tools (ps(1), top(1), ...). These programs don't all do the same thing in
> looking for System.map files. depmod(8) doesn't need a System.map file if
> it's operating on the currently running kernel. ps(1) and klogd(8) like to
> find a System.map file, but don't look in the same places.
I get what seem to be correct /var/log/messages files even though my System.map
link is pointing to the wrong System.map-2.2.whatever. Likewise, the ps(1) and
top(1) commands work as expected.
> You may have noticed that I have taken the liberty of cross-posting this
> message to os.linux.development. Although this may seem a little bit odd, or
> off-topic for this newsgroup, but I guess that the only people who can
> really clarify what system.map is used for and how you should handle two
> kernels&map files are the guys who actually know something about the
> source-code :)
>
> ------------------------------------------------------------
>
> >
> > All this talk about the "system.map" file prompted me to look
> > at my directory, /boot.
> > I guess my question is: does anyone (i.e., any process,
> > including the kernel) use these symbolic links? Because if so,
> > I should change them to point to the kernel I normally use. But
> > that raises another question: If I boot a different kernel,
> > perhaps because I installed one that is no good as the latest
> > one, I will get the wrong values for the symbolic links. What
> > are the consequences of this?
> >
--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 73926.
/( )\ Shrewsbury, New Jersey
^^-^^ 2:20pm up 5 days, 19:58, 3 users, load average: 2.08, 2.12, 2.09
------------------------------
From: Andres Soolo <[EMAIL PROTECTED]>
Subject: Re: Microsoft's Anti Linux Page
Date: 15 Oct 2000 18:53:57 GMT
Tony Lawrence <[EMAIL PROTECTED]> wrote:
>> 'Linux cannot deliver on the hype', indeed...
> Actually, it's great that Microsoft attacks Linux. As someone
> once said about newspaper articles, say anything you want, just
> spell the name right- the point being that any attack makes folks
I guess it was Rockefeller, one of the most famous monopolists in
history ;-)
And it was Mahatma Ghandi who once said a revolution has four seps:
1. they ignore you;
2. they laugh at you;
3. they fight you;
4. we win.
> Most sales folks know that you do not mention your competitors
> unless you absolutely have to. If there is any chance your
> customer doesn't know your competitors, you sure don't want to
> help them find out, do you? Yet that's just what Microsoft is
> doing, so they must feel very very threatened..
My guess is too many people started calling Microsoft to ask about
Linux (and I'm sure some of them asked when Microsoft is going to
ship it), so Microsoft is now trying to assume the role of the
`independent specialist' and, no doubt, publish more things like
that one in the near future. Damage control, to say it briefly.
--
Andres Soolo <[EMAIL PROTECTED]>
To teach is to learn.
------------------------------
From: ray <[EMAIL PROTECTED]>
Crossposted-To: linux.debian.user,linux.debian.www
Subject: Re: What is a good graphical mail client?
Date: Sun, 15 Oct 2000 19:04:13 GMT
Tom Huckstep wrote:
> By the way, I've tried mozilla, but it is sooooo sloooooow on my
> machine. I'd try netscape, but fear the same problem, and anyway, I
> don't know what to do to get Netscape working from the base install.
> Tom Huckstep
> --
> Tom Huckstep <[EMAIL PROTECTED]> wrote in message
> news:8scons$b9q$[EMAIL PROTECTED]...
> > Is there such a thing as a decent graphical mail program for Linux,
> > which supports POP3 and SMTP? I have spent all day looking through
> > dselect for such a thing.
> > I would like a simple interface which will let me save messages in
> an
> > outbox, to be sent when I connect to the internet via my modem. I
> > have tried both balsa and spruce, but both seem to be very early in
> > development, and I can't get either to work with any degree of
> > success. Emacs doesn't seem to offer any easily configured mail
> > clients either. I don't want to have to go through exim or
> sendmail,
> > but straight to my ISP's server.
> > Ashamed as I am to admit it, Outlook Express does nearly all that I
> > want. POP3 and STMP, easy folder management, along with an outbox
> for
> > saving messages when offline, and a sent items folder. (The search
> > facility is also excellent).
> > If you use a program that has these features, or know of one, please
> > let me know. (I will also be happy to use a text-based one, if it
> is
> > any good).
> >
> > Tom Huckstep
> >
> >
> >
> >
We may be starting a distro, WM, desktop flame war, here, but. i have
used several I liked. Actually, Nutscrape is not slow on my machine,
though, certainly, Mozilla is. I do not care for KDE, preferring Gnome
and either sawfish or enlightenment, but I do have KDE installed, and my
decided email favorite is kmail. It's in kdenetwork package. It's tiny,
fast, has all the features I need. It works great with gnome. This new
evolution they are building I have looked at, it's not for me, though it
is interesting. I just need basic folders, addressbooks, etc., and kmail
does all I need.
--
Ray R. Jones
Errors have been made. Others will be blamed.
[EMAIL PROTECTED]
HTTP://raymondjones.net
------------------------------
From: Giuseppi Tubiere <[EMAIL PROTECTED]>
Crossposted-To:
comp.os.linux.help,comp.os.linux.networking,comp.os.linux.questions,comp.os.linux.redhat,comp.os.linux.setup,linux.redhat.install,linux.redhat.misc
Subject: Re: IPChains and Cable Modems - Fequently loosing connectivity to the Internet
Date: Sun, 15 Oct 2000 14:07:12 -0500
Kevin,
You never mention if the IP address changes as you restart the Cable
Modem.
Based purely on the symptom data, it sounds like both of you are
loosing IP address @home. I'm not sure how to do this yet on Linux,
but check the address generated after modem reboot, likely it's a new
number.
If the number's changed, then you'll have to check your DCHP lease
renewal times.
Another test for this would be to release and renew your RH DCHP card
address [don't know how yet, but sure linux will do this like winsux
does.]
Cable modems will change addresses on a whim [or latest screw-up
@home], you'll need to adjust for constantly changing IP address.
hope this helps!
Sam Clark
[EMAIL PROTECTED]
[EMAIL PROTECTED] is my spam filter.
On Sun, 15 Oct 2000 07:36:58 GMT, "Kevin Safford" <[EMAIL PROTECTED]>
wrote:
>
>"Vinson Armstead" <[EMAIL PROTECTED]> wrote in message
>news:K65G5.48264$[EMAIL PROTECTED]...
>> This is a strange problem...Any suggestions or advice would be greatly
>> appreciated
>>
>> I have been having a problem with keeping my cable modem connection active
>> when using my RH (first 6.2 now 7.0) server as a Firewall (running
>IPChains
>> 1.3.9-17)
>>
>
>I ran across your description while searching for a possible
>explanation to a very similar problem. I recently made an old
>486 into a linux firewall/router for my cable modem connection (I am on
>@home). I have been having the exact same problem as you describe.
>
>I am running Mandrake 7.0 with 2 ne2000 ISA cards. The symptom I have is,
>after using the browser on my PC (par t of my internal network), the
>connection seems to "hang". I can find no usage pattern that causes this to
>happen or accelerates the problem, other than it occurs when I am actively
>browsing (as opposed to it happening when the machines are sitting
>idle.)Here's what I have discovered so far when the connection hangs:
>
>1) I cannot ping to the outside world from either my linux box or my PC.
>
>2) I can ping both the internal (192.168.1.1) and external address from both
>the linux and PC.
>
>3) If I try to telnet (or ftp) from my PC into my linux box, I make the
>connection (and see the connection in the syslog), but I do not get the
>login prompt (i.e., nothing is sent back to the PC). (I find this very,
>very strange and kind of annoying, since I have to go find a keyboard to
>connect to the linux box again.)
>
>4) Restarting the network will not help: the DHCP request from my linux box
>times out. Rebooting the linux box does not help. Same problem. The ONLY
>way to get back is to unplug my cable modem (I have an RCA modem) and plug
>it back in (simply turning it on and off with the power switch doesn't help;
>I believe that unplugging this particular modem causes it to reinitialize
>itself.)
>
>I called ATT support this morning, and they claim that my cable modem itself
>is pingable and that the problem is something with my machine. And, since
>they don't support linux, I'm on my own. =)
>
>I have searched through the various HOWTOs and FAQs looking for anything
>related to this and have been unsucessful. I have played with my IPCHAINS
>commands to see if they were the problem. Nothing I can think of has helped
>solve the problem.
>
>And, like you describe, my connection worked fine for a long time when the
>modem directly connected to my PC.
>
>Any thoughts would be greatly appreciated. I've gotten quite tired of
>unplugging my cable modem and restarting my network.
>
>Kevin
>[EMAIL PROTECTED]
>
>
>
------------------------------
From: "Lamar Thomas" <[EMAIL PROTECTED]>
Crossposted-To:
comp.os.linux,comp.os.linux.admin,comp.os.linux.help,comp.os.linux.networking,comp.os.linux.questions,comp.os.linux.setup,linux.redhat.applixware
Subject: Where do "Programs" go?
Date: Sun, 15 Oct 2000 19:30:37 GMT
When you install programs on Linux RH 6.2 where do they go? I mean, if I
were installing a program on Windows it would install to "C:\Programs
Files\(ProgramFolder". Where do they go on Linux? I am setting up my first
Linux system and I want to make sure I leave enough room a the "Right"
partition for installing my programs. Do they go to the /usr partition?
Thanks for your help.
Lamar
------------------------------
From: =?iso-8859-1?Q?St=E9phane?= K. <[EMAIL PROTECTED]>
Crossposted-To: uk.comp.os.linux
Subject: How to execute a program at startup?
Date: Sun, 15 Oct 2000 21:40:42 +0200
Hi there,
Does anybody know how to execute a program at startup?
The situation: I have to exec my ddns everytime I turn my machine on
because I have dynamic IP. OK.
BUT I cannot execute it as normal user (otherwise I would just put a
line in my .bashrc) it gives me a strange answer
[stephanek@kastar stephanek]$ ddns --modify
error: unknown port in configuration file: http
so I have to execute the script as root, then it works. How do I tell
the init program to run this script (as root) everytime I turn the
computer on? Without logging in as root though?
Thanks for your help folks,
PS: all this is for my ftp server to run properly... Who wants leech
access?
--
*******************************************************************************
* Stephane K. * [EMAIL PROTECTED] * Are you
nuts? *
* * *
No?... *
* Humanoid, __ __ Bruxelles, Earth
* *
* / \/ \ * You
should! *
***************/********\******************************************************
\ /
\ / ~~~~~~~~~~~! members.fortunecity.com
\ / ~~~~~~/stephen79k
\ / ~~~~~~~~
-------\/----------------------------------------
------------------------------
From: Bryan Robinson <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.setup
Subject: Warning: Setting Locale Failed
Date: Sun, 15 Oct 2000 15:40:59 -0400
I'm trying to get asDrinks to work on my system. When I try to run the
script, I get the following message:
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = "en",
LC_ALL = "en",
LANG = "en"
are supported and installed on your system.
This doesn't seem to be well documented. Can anyone tell me how to
change these settings, or at least where to look for info?
Thanks much,
Bryan Robinson
[EMAIL PROTECTED]
------------------------------
From: Andres Soolo <[EMAIL PROTECTED]>
Subject: Re: Linux Chat Server
Date: 15 Oct 2000 19:56:35 GMT
Zer0Oxygen <[EMAIL PROTECTED]> wrote:
> Does anyone know of a good linux chat server that can be accessed using
> telnet? I have tried out a few like jdkchat, nexus, nuts, and
> geektalkd... But they are all very plain. I'm looking for one that will
> notify users either visually or verbally when there is activity.
One of the fundamental tasks of a chat server is to report all
relevant activity to the users, mostly in real time. If that is not
what you meant by `visual notification', please explain further.
--
Andres Soolo <[EMAIL PROTECTED]>
The two most common things in the universe are hydrogen and stupidity.
------------------------------
From: "J.Smith" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.networking,comp.os.linux.setup
Subject: Re: Where do "Programs" go?
Date: Sun, 15 Oct 2000 21:57:11 +0200
Common locations are /bin, /sbin, /usr/bin, /usr/sbin, /usr/local/bin,
/usr/local/sbin. This is were the executables live. Shared libraries (dll's,
in windows terms) usually go in /lib or /usr/lib. You might want to read the
Filesystem Hierarchy Standard (fhs) for more information about which files
should go in which directories. Check it out at http://www.pathname.com/fhs/
"Lamar Thomas" <[EMAIL PROTECTED]> wrote in message
news:xBnG5.322091$[EMAIL PROTECTED]...
> When you install programs on Linux RH 6.2 where do they go? I mean, if I
> were installing a program on Windows it would install to "C:\Programs
> Files\(ProgramFolder". Where do they go on Linux? I am setting up my
first
> Linux system and I want to make sure I leave enough room a the "Right"
> partition for installing my programs. Do they go to the /usr partition?
> Thanks for your help.
>
> Lamar
>
>
>
------------------------------
From: David Mehringer <[EMAIL PROTECTED]>
Subject: XFree 4.0
Date: Sun, 15 Oct 2000 14:58:27 -0500
I've just installed red hat 7 and now X doesn't work properly for
me. For example, moving windows around on the screen causes the display to
get totally screwed up and there is no way to refresh it. Having read some
other postings and checked the XFree86 site, it seems my card is not
supported under XF86 4.0; I'm using the SVGA driver, and the version whcih
ships with RH7 is 3.3.6 not 4.0.1. So, I'd like advice on what I should do
now. I backed up my RH6.2 installation before insalling 7, so I could just
blow away 7 and resurrect 6.2. I'd prefer not to do this, because it blows
away other new packages which might be useful. I could try to downgrade
back to XF86-3.3.6 (if I can figure out how to do this with rpm), but my
guess there are a lot of packages which have been installed that depend on
XF-4.0 so downgrading could be an enormous chore. Don't particularly want
to have to buy a new graphics card either, but if someone could suggest one
that costs $100 or less and is supported by XF86-4, then I'd consider that.
I'm not a big 3D gamer.
If you could email as well as post that would be great; my news feed is
often flaky.
--
David Mehringer, Ph.D. University of Illinois
[EMAIL PROTECTED] National Center for Supercomputing
Research Scientist, Applications/Department of Astronomy
Software Applications Developer, 1002 W. Green St.
BIMA Data Archivist Urbana, IL 61801 USA
voice: 217 244 5468 fax: 217 244 7638
http://monet.astro.uiuc.edu/~dmehring/dmehring.html
------------------------------
From: "J.Smith" <[EMAIL PROTECTED]>
Subject: Re: What is a system map, part 2?
Date: Sun, 15 Oct 2000 22:04:04 +0200
The following is cut 'n pasted from the reply of "Ben Caradoc-Davies", a
friendly netizen who replyed to a similar tread in
comp.os.linux/development:
===========================================
/boot/System.map is used by ksymoops to convert addresses (in kernel oops)
into symbols.
man ksymoops
Does lilo need it?
No.
Is it needed for loadable modules?
No.
Do other applications use this file?
There is nothing stopping them. :-)
/boot/System.map is a symbolic link to the appropriate map file. You can do
this by hand, or in the case of recent RedHat releases, this link is updated
at boot time by the following in rc.sysinit:
if [ -L /boot/System.map -a -r /boot/System.map-`uname -r` ] ; then
ln -s -f System.map-`uname -r` /boot/System.map
fi
------------------------------
From: Andres Soolo <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.networking
Subject: Re: [Help Me] UDP Network Programming
Date: 15 Oct 2000 20:04:05 GMT
In comp.os.linux.misc Bomshik Kim <[EMAIL PROTECTED]> wrote:
> I do not want to receive the out-of-date UDP packets.
> When I restart process B, I just want to ignore the old UDP packets,
> and to receive the new UDP packets.
The UDP does not do session management, so there is no way to tell
on that layer which packets are new and which are outdated. If you
want to get that functionality on top of UDP, you have to implement
some session data yourself (such as making the client mark outgoing
packets with a session identifier which is handed to them by the server
at first message transmitted--but, depending on your exact situations,
there may be better ways). Or, if your transmissions happen to
be session-based, it might be better to use TCP instead of UDP.
> ps)please reply to both newsgroup and [EMAIL PROTECTED]
What is the point of a newsgroup when the people use private mail
instead? :-)
--
Andres Soolo <[EMAIL PROTECTED]>
Beware of Programmers who carry screwdrivers.
-- Leonard Brandwein
------------------------------
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End of Linux-Misc Digest
******************************
