ulimit -c for core dumps

[Jason Roscoe]

Hi,
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.

Shell interaction
% ulimit -H -c
unlimited
% ulimit -S -c
0
% bash --version
GNU bash, version 2.05b.0(1)-release (i386-pc-linux-gnu)
Copyright (C) 2002 Free Software Foundation, Inc.
% ulimit -c 512
% ulimit -S -c
512
% 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
%

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>

int main(int argc, char* argv[])
{
   char* c;
   int mult=1024;
   int sz;
   struct rlimit rlim;

   if(getrlimit(RLIMIT_CORE,&rlim))
       printf("error getting rlimit\n");

   printf("rlim_cur,rlim_max = %u,%u\n",rlim.rlim_cur,rlim.rlim_max);

   if(argc>1)
       mult=atoi(argv[1]);

   sz=mult*1024;
   c=malloc(sz);
   if(!c)
       {
       printf("unable to malloc\n");
       exit(EXIT_FAILURE);
       }

  printf("malloced %u bytes my pid is %u\n",sz,getpid());
  raise(SIGSEGV);

  return EXIT_SUCCESS;
}