资源和限制

#include  <sys/types.h>

#include  <sys/resource.h>

#include  <sys/time.h>

#include <stdio.h>

#include  <unistd.h>

#include <stdlib.h>

#include  <math.h>

void work()

{

    FILE *f=tmpfile();

    for(int i=0;i<10000;++i)

    {

        fprintf(f,"Do something output\n");

        if(ferror(f))

        {

            fprintf(stderr,"Error writing to temporary file\n");

            exit(1);

        }

    }

    double x=4.5;

    for(int i=0;i<1000000;++i)

        x=log(x*x+3.21);

}

int main(int argc,char * argv[])

{

    struct rusage r_usage;

    work();

    getrusage(RUSAGE_SELF,&r_usage);

    printf("CPU usage:User = %ld. %06ld, System=%ld. %06ld\n",

           r_usage.ru_utime.tv_sec,r_usage.ru_utime.tv_usec,

           r_usage.ru_stime.tv_sec,r_usage.ru_stime.tv_usec);

    int priority;

    priority = getpriority(PRIO_PROCESS,getpid());

    printf("Current priority = %d\n",priority);

    struct rlimit r_limit;

    getrlimit(RLIMIT_FSIZE,&r_limit);

    printf("Current FSIZE limit : soft = %ld,hard = %ld\n",

           r_limit.rlim_cur,r_limit.rlim_max);

    r_limit.rlim_cur=2048;

    r_limit.rlim_max=4096;

    printf("Setting a 2K file size limit\n");

    setrlimit(RLIMIT_FSIZE,&r_limit);

    work();

    exit(0);

}