C won't execute?!??!
 

Hi,

For some reason one of my computers has stopped executing C programs. On startup it will be fine for a bit and then (presumably after some unknown event) will not run any of my c programs.

I can compile and run a new C program that will work and it will run Tcl and bash scripts but not C.

Sorry there isn't more information but it hasn't happened many times.

Thanks,

ectof

What distribution are you using? And what exact error message are you getting when you try to run programs that don't work?

I think items in red and blue contradict each other.

Sorry, the question was not well posed.

The distro is a quite old version of suse (7.?) and gcc is 3.3, it has been reasonably stable up to now.

I meant that I could compile and run the executable of a new program, but I cannot run programs that have been compiled previously i.e. before the last boot up.

ectof

So, post (copy-paste) the source, command lines you used to compile and link, command lines you used to invoke the newly produced programs and the error messages they produce.

Thanks for your help so far.
So I managed to find out a bit more.
The program I was testing with was just the most basic 'hello_world.c'

When I compile and run

#include <stdio.h>

int main() {
printf("hello world\n");
return 0;
}

gcc 'hello_world.c'
./a.out

it gives the expected 'hello world'

But, if I do

gcc 'hello_world.c' -lgpibapi
./a.out

It seems to compile OK and then when I execute it just hangs.
I then tried

gcc 'hello_world.c' -lm
./a.out

and again it executes.
As I say the on immediate startup things are OK but then it stops working.
If you have any idea why this might happen for this library that would be great. I guess I am doing something to screw up the gpib, but I have no idea what.

ectof

So, only programs that use that one library are not working, correct?

Yes so far as I'm aware but I haven't tested all the libraries.

Can you post ldd a.out (when the program doesn't execute)? Do you happen to have two versions of libgpibapi with the same soname? Also post ls -l /usr/lib/libgpibapi/libgpibapi* (adjust path as applicable.)
Kevin Barry

Hi this is the output from the session log

ldd a.out
linux-gate.so.1 => (0xffffe000)
libgpibapi.so.2 => /usr/local/lib/libgpibapi.so.2 (0x40032000)
libc.so.6 => /lib/tls/libc.so.6 (0x40091000)
libnipalu.so.1 => /usr/local/lib/libnipalu.so.1 (0x401a6000)
libgpibconf.so.2 => /usr/local/lib/libgpibconf.so.2 (0x4023b000)
libm.so.6 => /lib/tls/libm.so.6 (0x40251000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
librt.so.1 => /lib/tls/librt.so.1 (0x40273000)
libdl.so.2 => /lib/libdl.so.2 (0x4027b000)
libpthread.so.0 => /lib/tls/libpthread.so.0 (0x4027e000)

ls -l /usr/local/lib/libgpibapi*
lrwxrwxrwx 1 root root 15 2005-09-16 16:09 /usr/local/lib/libgpibapi.so -> libgpibapi.so.2
lrwxrwxrwx 1 root root 19 2005-09-16 16:09 /usr/local/lib/libgpibapi.so.2 -> libgpibapi.so.2.3.1
lrwxrwxrwx 1 root root 49 2005-09-16 16:09 /usr/local/lib/libgpibapi.so.2.3.1 -> /usr/local/natinst/ni4882/lib/libgpibapi.so.2.3.1

ls -l /usr/local/natinst/ni4882/lib/libgpibapi.so.2.3.1
-rwxr-xr-x 1 root root 379735 2005-03-02 20:25 /usr/local/natinst/ni4882/lib/libgpibapi.so.2.3.1

Have you recompiled all (or at least one) of the non-functioning programs? Maybe you updated the library and they are linked against the wrong version.

It seems like it has something to do with the loading of that particular library (i.e. the _init function.) Why do you try to link to it? Does it replace something contained in libm?
Kevin Barry

I have tried recompiling a few of the programs, which didn't work.

Some of the other programs need it.

Thanks.

Having googled for "libgpibapi", here are two promising results you may like to pursue.

http://forums.ni.com/ni/board/messag...ssage.id=17597

http://linux.derkeiler.com/pdf/Newsg...1/msg00165.pdf

End

Thanks, that's kind of embarrassing. This looks like it may be a much more common problem than I thought.