Re: need explanation ulimit -c for limiting core dumps

[Matthew Woehlke]

Chet Ramey wrote:
> jason.roscoe@gmail.com wrote:
> > I'm trying to limit the size of coredumps using 'ulimit -c'.  Can
> someone please explain why a core file gets generated from the coretest
> program (source is below)?
> > Thanks for any help or suggestions.
> >
> > % ulimit -H -c
> > 512
> > % ./coretest 2048
> > rlim_cur,rlim_max = 524288,524288
> > malloced 2097152 bytes my pid is 21255
> > Segmentation fault (core dumped)
> > % ls -l core
> > -rw-------  1 jacr swdvt 2265088 2006-10-19 14:24 core
>
> Are you sure that's not an old core file?  My Linux testing indicates that
> the coredump bit is set in the exit status, but no core file is actually
> created:
>
> $ ulimit -c 512
> $ ./xcore 2048
> rlim_cur,rlim_max = 524288,524288
> malloced 2097152 bytes my pid is 7661
> Segmentation fault (core dumped)
> $ ls -ls core
> /bin/ls: core: No such file or directory

You sure your Linux makes 'core' and not 'core.<pid>', right? You might 
want to do 'ls -ls core*' instead...

$ ls core*
ls: core*: No such file or directory
$ ( ulimit -c 512 ; ./core.x )
rlim_cur,rlim_max = 524288,524288
malloced 1048576 bytes my pid is 26891
$ ls core.*
core.26891

--
Matthew
When on POSIX, do as POSIX mandates.