How to increase the limit of “maximum open files” in C?
The default limit for the max open files on Mac OS X is 256 (ulimit -n) and my application needs about 400 file handlers.
I tried to change the limit with setrlimit() but even if the function executes correctly, i'm still limited to 256.
Here is the test program I use (compiled with gcc):
and the output is:
I cannot ask the people who use my application to poke inside a /etc file or something. I need the application to do it by itself.
I tried to change the limit with setrlimit() but even if the function executes correctly, i'm still limited to 256.
Here is the test program I use (compiled with gcc):
#include <stdio.h>
#include <sys/resource.h>
main()
{
struct rlimit rlp;
FILE *fp[10000];
int i;
getrlimit(RLIMIT_NOFILE, &rlp);
printf("before %d %d ", rlp.rlim_cur, rlp.rlim_max);
rlp.rlim_cur = 10000;
setrlimit(RLIMIT_NOFILE, &rlp);
getrlimit(RLIMIT_NOFILE, &rlp);
printf("after %d %d ", rlp.rlim_cur, rlp.rlim_max);
for(i=0;i<10000;i++) {
fp = fopen("a.out", "r");
if(fp==0) { printf("failed after %d ", i); break; }
}
}
and the output is:
before 256 -1
after 10000 -1
failed after 253
I cannot ask the people who use my application to poke inside a /etc file or something. I need the application to do it by itself.
MacBook Pro 15", Mac OS X (10.6.4)
