Linux-Development-Sys Digest #130, Volume #8 Fri, 8 Sep 00 10:13:16 EDT
Contents:
Re: ext3 in 2.4.0-test kernels (Johan Kullstam)
Re: negative dentry (Karl Heyes)
Re: Load/unload modules programatically (Karl Heyes)
is there a way to convert java application bytecode to executable file to run on
linux. ("Richard Lim")
Re: is there a way to convert java application bytecode to executable file to run on
linux. (Juergen Kreileder)
cursor settings (B.Lim)
Re: buffer_dirty - what's the @#$%? ("Ian Dichkovsky")
printk output in X? (Tasos Kotaras)
Re: buffer_dirty - what's the @#$%? (Robert Kaiser)
Re: Ftp library (Arnstein Oseland)
Re: buffer_dirty - what's the @#$%? ("Ian Dichkovsky")
Problem with fopen under RedHat 6.2 (Doug Dodson)
Re: Problem with fopen under RedHat 6.2 (Andreas Kahari)
Re: printk output in X? ("[EMAIL PROTECTED]")
Re: Problem with fopen under RedHat 6.2 ("Nikita V. Youshchenko")
Re: buffer_dirty - what's the @#$%? ([EMAIL PROTECTED])
Re: help with linux network programming (Byron)
Re: buffer_dirty - what's the @#$%? (Bob Hauck)
----------------------------------------------------------------------------
Subject: Re: ext3 in 2.4.0-test kernels
From: Johan Kullstam <[EMAIL PROTECTED]>
Date: Thu, 07 Sep 2000 22:45:22 GMT
[EMAIL PROTECTED] (Daniel Robert Franklin) writes:
> Stefan Boresch <[EMAIL PROTECTED]> writes:
>
>
> >How do I get
> >ext3 filesystem support in the 2.4.0-test kernels. Is it not
> >already there (I believe remembering something like this), but
> >I find no flag for configuring it. I downloaded the ext3-0.0.2f
> >package from kernel org, but that seems to contain only diffs
> >agains a RH 2.2.16 kernel and a 2.2.17-pre something. I would
> >guess (haven't tried) that those patches are useless for 2.4.0.
>
> It's not there yet. I think they are trying to hammer out some
> common-functionality between the various journalled FS projects before
> putting ext3/Reiser/XFS etc. in (plus I think XFS needs some more work). I'd
> expect something early in 2.5, probably backported to 2.4.x, x > 0.
reiserfs is pretty stable these days. it is definately usable. i've
been using it hard core for 6 months so far without problems. still,
fsck for reiserfs is a bit primitive/broken so if the journal fails
you could be toast. as always -- BACK UP YOUR DATA!
except for the annoyance factor, it doesn't really matter that the
stock kernel doesn't ship it. it's just a matter of patching your
kernel. reiserfs works with late model 2.2.* and 2.4.0-test* kernels.
--
J o h a n K u l l s t a m
[[EMAIL PROTECTED]]
Don't Fear the Penguin!
------------------------------
From: Karl Heyes <[EMAIL PROTECTED]>
Subject: Re: negative dentry
Date: Fri, 08 Sep 2000 00:23:19 +0000
In article <[EMAIL PROTECTED]>, "Jay Randall"
<[EMAIL PROTECTED]> wrote:
> Hi,
>
> Can somebody please explain to me what a 'negative dentry' is and what it is
> used for.
a dentry is a structure that contains a file and an inode number ( a file can
have many names). These are created when a name is queried in the VFS.
If th filesystem has the file, it associates the file the dentry, if not the
dentry still exists with no file associated with it.
The upshot is that if a filename is looked up, the the VFS cache of dentries is
hit before the FS -depandant stuff. helping to improve lookup performance.
negative dentries you could think of as ghost filenames that don't show up in
you ls listings but indicate filenames often looked for but never found.
eg
you start vi alot, vi is located in /usr/bin/vi, your path is set to
/bin:/usr/bin therefore /bin/vi is looked up first. /bin/vi never exists but
is sought many times (I'm not counting caching by shells ie rehash). so /bin/vi
becomes a negative dentry.
karl
------------------------------
From: Karl Heyes <[EMAIL PROTECTED]>
Subject: Re: Load/unload modules programatically
Date: Fri, 08 Sep 2000 00:41:47 +0000
In article <39b7cef2$0$[EMAIL PROTECTED]>, "Chris"
<[EMAIL PROTECTED]> wrote:
> Is there a way to load and unload kernel modules from within a user
> application? I am currently using a shell script consisting of insmod, search
> /proc/devices for major number, mknod. Then another script using rmmod to
> unload the module when the app closes.
>
> What I really want is to have the application manage the loading and
> unloading of the module without having to rely on the shell.
>
The loading of modules is a root only task, you don't want normal users
iniitiating module loading directly. kmod is created which exec modprobe then
in turn insmod.
The above script could be done but it needs root, there maybe capabilities
provided by 2.4 for this sort of task
karl.
------------------------------
From: "Richard Lim" <[EMAIL PROTECTED]>
Crossposted-To:
comp.lang.java.gui,comp.lang.java.help,comp.lang.java.programmer,comp.os.linux.development.apps
Subject: is there a way to convert java application bytecode to executable file to run
on linux.
Date: Fri, 8 Sep 2000 08:34:58 +0800
is there a way to convert java application bytecode to executable file to
run on linux without the runtime environment.
------------------------------
From: Juergen Kreileder <[EMAIL PROTECTED]>
Crossposted-To:
comp.lang.java.gui,comp.lang.java.help,comp.lang.java.programmer,comp.os.linux.development.apps
Subject: Re: is there a way to convert java application bytecode to executable file to
run on linux.
Date: 08 Sep 2000 03:23:15 +0200
>>>>> "Richard" == Richard Lim <[EMAIL PROTECTED]> writes:
Richard> is there a way to convert java application bytecode to
Richard> executable file to run on linux without the runtime
Richard> environment.
Take a look a GCJ: http://sources.redhat.com/java/
Juergen
--
Juergen Kreileder, Blackdown Java-Linux Team
http://www.blackdown.org/java-linux.html
JVM'01: http://www.usenix.org/events/jvm01/
------------------------------
From: [EMAIL PROTECTED] (B.Lim)
Subject: cursor settings
Date: 8 Sep 2000 03:55:18 GMT
How would I go about enabling a non-blinking block cursor to be compiled
into the kernel? Is there a way to change the colour as well? I've read
VGA-softcursor.txt in the source tree but it doesn't say how to compile
it in the kernel - only through crude 'echo' commands. I've tried
modifying /usr/src/linux/include/linux/console_struct.h but I don't
know how to disable the blinking. Any suggestions?
Thanks.
--
B.Lim - http://unixbox.freewebsites.com
GNUPG key fingerprint = C94E C318 90D5 38F7 EF1A 657B DDC9 7BD7 5BC2 AE1E
"Security through obscurity is an unworkable principle."
------------------------------
From: "Ian Dichkovsky" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.hardware,comp.os.linux.misc,comp.os.linux.questions
Subject: Re: buffer_dirty - what's the @#$%?
Date: Fri, 8 Sep 2000 10:11:55 +0300
> > I copy file _FROM_ floppy to hard
> it has time. If you remove the floppy before it gets around to
> doing/finishing the copy the buffer is "dirty."
I don't remove floppy before umount.
>
> sync
>
> forces the write (rather than waiting).
I know about sync
so maybe I must type
mount /mnt/fd; cp /mnt/fd/* /prj; sync; umount /mnt/fd
Bye!
------------------------------
From: Tasos Kotaras <[EMAIL PROTECTED]>
Subject: printk output in X?
Date: Fri, 08 Sep 2000 11:09:05 +0300
Hello everybody,
This is a newbie question, as I have just started meddling with Linux
device drivers: I have a problem getting output from printk while I'm
in KDE. Of course, while I'm in in text mode everything works OK.
I know that X 'covers' the virtual terminal which displays the
messages,
but I wonder why even the good-old 'xterm -C' doesn't do the trick...
Is there anything I can do to get the printk output displayed while I'm
in X?
I would be grateful for any help.
--
`\|||/
(@@)
_ooO_(_)_Ooo________________________________
______|_____|_____|_____|_____|_____|_____|_____|
_____|__________|_____|_____|____|_____|____|_____
|________Tasos Kotaras___|_____|____|_____|_____|
___|___|__Telecom Software Engineer_____|____|____
_____|_____Access Net & Wireless Comm Dept
|_______|___INTRACOM___|_____|______|______|____
__|___|______Peania 19002, Greece_|_____|____
___e-mail: [EMAIL PROTECTED]|____|____|____|
|_____Phone: +30 1 6690185_______|_____|______
------------------------------
From: [EMAIL PROTECTED] (Robert Kaiser)
Crossposted-To: comp.os.linux.hardware,comp.os.linux.misc,comp.os.linux.questions
Subject: Re: buffer_dirty - what's the @#$%?
Date: 8 Sep 2000 07:47:49 GMT
In article <8p7su8$i1j$[EMAIL PROTECTED]>,
"Ian Dichkovsky" <[EMAIL PROTECTED]> writes:
>> > So, what it mean - buffer_dirty ?
>>
>> Caching. It happens in Windows if you speed Windows up (but Windows
>> defaults to turn off write caching). When you write a file to floppy all
>
> I copy file _FROM_ floppy to hard
>
> mount /mnt/fd; cp /mnt/fd/* /prj; umount /mnt/fd
>
Even if you only read from floppy, depending on the filesystem type,
the system may be trying to update access time entries.
Try mounting the floppy read-only.
Rob
------------------------------
From: Arnstein Oseland <[EMAIL PROTECTED]>
Subject: Re: Ftp library
Date: Fri, 08 Sep 2000 10:15:07 +0200
Patrick Collet wrote:
>
> Hi,
>
> I'm looking for an ftp library on Linux. Do you know anyone ? Do you know
> which one is the best ?
Check out libcurl. http://curl.haxx.se
Arnstein
------------------------------
From: "Ian Dichkovsky" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.hardware,comp.os.linux.misc,comp.os.linux.questions
Subject: Re: buffer_dirty - what's the @#$%?
Date: Fri, 8 Sep 2000 13:02:27 +0300
Thank all for the answers, BUT i don't understand.
Sorry.
Why I must mount floppy read-only?
Why I must see those messages ..... buffer_dirty....?
Can I do simple things without annoying messages ?
1. insert floppy
2. mount floppy
3. copy from floppy
4. umount floppy
5. remove floppy
"Robert Kaiser" <[EMAIL PROTECTED]> wrote in message
news:8pa5j5$mr5$[EMAIL PROTECTED]...
> In article <8p7su8$i1j$[EMAIL PROTECTED]>,
> "Ian Dichkovsky" <[EMAIL PROTECTED]> writes:
> >> > So, what it mean - buffer_dirty ?
> >>
> >> Caching. It happens in Windows if you speed Windows up (but Windows
> >> defaults to turn off write caching). When you write a file to floppy
all
> >
> > I copy file _FROM_ floppy to hard
> >
> > mount /mnt/fd; cp /mnt/fd/* /prj; umount /mnt/fd
> >
>
> Even if you only read from floppy, depending on the filesystem type,
> the system may be trying to update access time entries.
>
> Try mounting the floppy read-only.
>
> Rob
------------------------------
From: Doug Dodson <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.development.apps,comp.os.linux.misc
Subject: Problem with fopen under RedHat 6.2
Date: Fri, 08 Sep 2000 07:39:24 -0400
This is a multi-part message in MIME format.
==============D16B8A998C0BEB58661D4412
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Hi,
We are trying to port some code over to a Linux PC running RedHat 6.2.
Compilation of the code is fine, however when we run, we get a
segmentation fault on one of our fopen calls. We seem to be able to
pass through the code once, but on the second iteration, we get the
fault. This code is being ported from a Solaris machine where it ran
fine. Here is the output of "gdb sfg core". We are just wondering if
this is a known bug or if anyone has seen behavior like this before.
Thanks for any help:
GNU gdb 19991004
Copyright 1998 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you
are
welcome to change it and/or distribute copies of it under certain
conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for
details.
This GDB was configured as "i386-redhat-linux"...
Core was generated by `sfg x w0000001.txt w0000002.txt w0000003.txt
w0000004.txt w0000005.txt w0001000'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /lib/libc.so.6...done.
Reading symbols from /lib/ld-linux.so.2...done.
#0 0x40074709 in chunk_alloc (ar_ptr=0x40109d60, nb=184) at
malloc.c:2763
2763 malloc.c: No such file or directory.
(gdb) where
#0 0x40074709 in chunk_alloc (ar_ptr=0x40109d60, nb=184) at
malloc.c:2763
#1 0x400745ce in __libc_malloc (bytes=176) at malloc.c:2696
#2 0x4006d83b in _IO_new_fopen (filename=0xbfff9cdc "w0000002.txt",
mode=0x8054708 "r") at iofopen.c:42
#3 0x804c8f0 in oratag ()
#4 0x8049e60 in main ()
#5 0x400339cb in __libc_start_main (main=0x8048b0c <main>, argc=992,
argv=0xbfffb954, init=0x80487d8 <_init>, fini=0x8053a5c <_fini>,
rtld_fini=0x4000ae60 <_dl_fini>, stack_end=0xbfffb94c)
at ../sysdeps/generic/libc-start.c:92
- Doug -
==============D16B8A998C0BEB58661D4412
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name="dodson.vcf"
Content-Transfer-Encoding: 7bit
Content-Description: Card for Doug Dodson
Content-Disposition: attachment;
filename="dodson.vcf"
begin:vcard
n:Dodson;Douglas
x-mozilla-html:FALSE
org:SRI International;State College, PA
adr:;;;;;;
version:2.1
email;internet:[EMAIL PROTECTED]
title:System/Network Administrator
fn:Douglas B. Dodson
end:vcard
==============D16B8A998C0BEB58661D4412==
------------------------------
Crossposted-To: comp.os.linux.development.apps,comp.os.linux.misc
Subject: Re: Problem with fopen under RedHat 6.2
From: [EMAIL PROTECTED] (Andreas Kahari)
Date: 8 Sep 2000 14:03:31 +0100
In article <[EMAIL PROTECTED]>,
Doug Dodson <[EMAIL PROTECTED]> wrote:
>-=-=-=-=-=-
>
>Hi,
>
>We are trying to port some code over to a Linux PC running RedHat 6.2.
>Compilation of the code is fine, however when we run, we get a
>segmentation fault on one of our fopen calls. We seem to be able to
>pass through the code once, but on the second iteration, we get the
>fault. This code is being ported from a Solaris machine where it ran
>fine. Here is the output of "gdb sfg core". We are just wondering if
>this is a known bug or if anyone has seen behavior like this before.
>Thanks for any help:
[cut]
Did you close the file properly before opening it again?
/A
--
Andreas K�h�ri, <URL:http://hello.to/andkaha/>.
All junk e-mail will be reported to the appropriate authorities.
========================================================================
The important thing is not to stop questioning.
------------------------------
From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
Subject: Re: printk output in X?
Date: Fri, 08 Sep 2000 14:56:39 +0200
Hi,
Printk has several levels of priority. (level 1 to 6 , I think)
>From this these it is decided where it should be directed.
This is setup by the logd.
I think by default redhat just chucks out everything on the console.
KDE may be redirecting this to your logs /var/log,
(this is usually done by klogd in your nit)
e.g. the level KERN_INFO goes to the messages log
and KERN_ERR to errorlog
etc..
You are properly using printk like printk("this is my message\n");
you should use it like printk(KERN_INFO"this is in message my log\n");
Then maybe set klogd to -c 3 , I think it is,
if you don't want messages flying all over the place.
Hope this helps,
Richard.
Tasos Kotaras wrote:
> Hello everybody,
>
> This is a newbie question, as I have just started meddling with Linux
>
> device drivers: I have a problem getting output from printk while I'm
> in KDE. Of course, while I'm in in text mode everything works OK.
>
> I know that X 'covers' the virtual terminal which displays the
> messages,
> but I wonder why even the good-old 'xterm -C' doesn't do the trick...
>
> Is there anything I can do to get the printk output displayed while I'm
> in X?
>
> I would be grateful for any help.
>
> --
> `\|||/
> (@@)
> _ooO_(_)_Ooo________________________________
> ______|_____|_____|_____|_____|_____|_____|_____|
> _____|__________|_____|_____|____|_____|____|_____
> |________Tasos Kotaras___|_____|____|_____|_____|
> ___|___|__Telecom Software Engineer_____|____|____
> _____|_____Access Net & Wireless Comm Dept
> |_______|___INTRACOM___|_____|______|______|____
> __|___|______Peania 19002, Greece_|_____|____
> ___e-mail: [EMAIL PROTECTED]|____|____|____|
> |_____Phone: +30 1 6690185_______|_____|______
------------------------------
From: "Nikita V. Youshchenko" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.development.apps,comp.os.linux.misc
Subject: Re: Problem with fopen under RedHat 6.2
Date: Fri, 08 Sep 2000 17:15:26 +0400
Looks like your program contails some dynamic memory error. E.g.
double-free()-ing some code, free()-ing something that is not
malloc()-ed, or accessing larger memory parts that were malloc()-ed.
These errors are known to be hard-to-find.
Try some malloc-debugging tool, e.g. electric-fence.
Nikita
> Hi,
>
> We are trying to port some code over to a Linux PC running RedHat 6.2.
> Compilation of the code is fine, however when we run, we get a
> segmentation fault on one of our fopen calls. We seem to be able to
> pass through the code once, but on the second iteration, we get the
> fault. This code is being ported from a Solaris machine where it ran
> fine. Here is the output of "gdb sfg core". We are just wondering if
> this is a known bug or if anyone has seen behavior like this before.
> Thanks for any help:
>
> GNU gdb 19991004
> Copyright 1998 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you
> are
> welcome to change it and/or distribute copies of it under certain
> conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB. Type "show warranty" for
> details.
> This GDB was configured as "i386-redhat-linux"...
> Core was generated by `sfg x w0000001.txt w0000002.txt w0000003.txt
> w0000004.txt w0000005.txt w0001000'.
> Program terminated with signal 11, Segmentation fault.
> Reading symbols from /lib/libc.so.6...done.
> Reading symbols from /lib/ld-linux.so.2...done.
> #0 0x40074709 in chunk_alloc (ar_ptr=0x40109d60, nb=184) at
> malloc.c:2763
> 2763 malloc.c: No such file or directory.
> (gdb) where
> #0 0x40074709 in chunk_alloc (ar_ptr=0x40109d60, nb=184) at
> malloc.c:2763
> #1 0x400745ce in __libc_malloc (bytes=176) at malloc.c:2696
> #2 0x4006d83b in _IO_new_fopen (filename=0xbfff9cdc "w0000002.txt",
> mode=0x8054708 "r") at iofopen.c:42
> #3 0x804c8f0 in oratag ()
> #4 0x8049e60 in main ()
> #5 0x400339cb in __libc_start_main (main=0x8048b0c <main>, argc=992,
> argv=0xbfffb954, init=0x80487d8 <_init>, fini=0x8053a5c <_fini>,
> rtld_fini=0x4000ae60 <_dl_fini>, stack_end=0xbfffb94c)
> at ../sysdeps/generic/libc-start.c:92
>
> - Doug -
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: buffer_dirty - what's the @#$%?
Crossposted-To: comp.os.linux.hardware,comp.os.linux.misc,comp.os.linux.questions
Date: 8 Sep 2000 09:21:52 -0400
In comp.os.linux.misc Ian Dichkovsky <[EMAIL PROTECTED]> wrote:
> 1. insert floppy
> 2. mount floppy
> 3. copy from floppy
> 4. umount floppy
> 5. remove floppy
Linux caches its writes. The copy from floppy may not be complete unless
you wait after step 3. Also, the programme may try to write to the floppy
to update the time stamp (indicating the last time the file on the floppy
was accessed) (if you interrupt it while it is writing to the fat
sector(s) on the floppy, it will probably not just be a bad time stamp)
and if you interrupt while it is writing to the floppy the record on the
floppy may be faulty.
After step 3 you can wait.
After step 3 you can force a buffer write using "sync"
Mounting the floppy as read only (which was another suggestion) should
prevent the system from trying to update the floppy record (if you are
copying from the floppy instead of to it and as long as the file is
completely read into memory it can later write to the hard disk).
On a system which caches writes you cannot just give a write command and
remove the media (and copying from a read/write floppy may involve a write
command to update the last access time). You have to ensure that the
command is finished.
A dirty buffer message indicates an incomplete result.
------------------------------
From: Byron <[EMAIL PROTECTED]>
Subject: Re: help with linux network programming
Date: Fri, 08 Sep 2000 21:34:49 +0800
Reply-To: [EMAIL PROTECTED]
[EMAIL PROTECTED] wrote:
> i want some help with writing simple network
> programs like
>
> generating IP packets, able to modify IP headers for
> IP address, flags in IP packets etc, detect arrival of
> packets and evaluate its headers, flags etc.
>
> thanks
> brian
Ok, if you want to be able to detect arrival of packets,
you can use a library called libpcap. It is a packet capture
library and deals with many layers/protocols. A very
powerful mechanism is supplied for you to be able to
access the data you want. e.g. byte offset into specific
protocol encapsulation layers. (ip, udp, tcp, icmp, ether,
fddi, etc....)
This library is covered in unix network programming,
but to use this library you need root privileges on the
machine.
If you don't want to use this, you can try using Linux
Packet sockets (SOCK_PACKET)
If you want to write packets to the network, then you
should be using raw sockets (RAW_SOCKET). You
will also need to enable the socket option IP_HDRINCL.
This will allow you to write complete packets. For this,
you'll need to know protocol header formats etc...
As for protocol header formats, I suggest
Internetworking with TCP/IP
Volume 1 Princiles, Protocols and Architecture
Douglas E. Comer
Prentice Hall Inc 1995
Otherwise, you should be fine with Unix Network Programming.
It's a great book. If you still have problems however, I have some
source I've developed for Linux that you might find useful.
(A PDU filter, being upgraded to multi-threaded PDU filter)
Byron Hammond
[EMAIL PROTECTED]
http://www.cs.curtin.edu.au/~hammondb/www
------------------------------
From: [EMAIL PROTECTED] (Bob Hauck)
Crossposted-To: comp.os.linux.hardware,comp.os.linux.misc,comp.os.linux.questions
Subject: Re: buffer_dirty - what's the @#$%?
Reply-To: bobh{at}haucks{dot}org
Date: Fri, 08 Sep 2000 13:43:43 GMT
On Fri, 8 Sep 2000 13:02:27 +0300, Ian Dichkovsky <[EMAIL PROTECTED]> wrote:
>1. insert floppy
>2. mount floppy
>3. copy from floppy
>4. umount floppy
>5. remove floppy
If floppy is FAT or VFAT (DOS or Windows) formatted, you should look at
the man page for mtools.
mcopy a:some-file /some/place
No mount/unmount needed.
mcopy
mdel
mdir
...etc...
--
-| Bob Hauck
-| To Whom You Are Speaking
-| http://www.haucks.org/
------------------------------
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End of Linux-Development-System Digest
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