text: #include <errno.h>
  #include <fcntl.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/resource.h>
  #include <unistd.h>
  #include "fdleak.h"
  
  int main(int argc, char **argv)
  {
     struct rlimit oldrlim;
     struct rlimit newrlim;
     int fd;
  
     CLOSE_INHERITED_FDS;
  
     if (getrlimit(RLIMIT_NOFILE, &oldrlim) < 0)
     {
        perror("getrlimit");
        exit(1);
     }
  
     newrlim.rlim_cur = oldrlim.rlim_max+1;
     newrlim.rlim_max = oldrlim.rlim_max;
     if (setrlimit(RLIMIT_NOFILE, &newrlim) == -1)
     {
        if (errno != EINVAL) {
           fprintf(stderr, "setrlimit exceeding hardlimit must set errno=EINVAL\n");
           exit(1);
        }
     }
     else
     {
          fprintf(stderr, "setrlimit exceeding hardlimit must return -1\n");
          exit(1);
     }
  
     newrlim.rlim_cur = oldrlim.rlim_max;
     newrlim.rlim_max = oldrlim.rlim_max+1;
     if (setrlimit(RLIMIT_NOFILE, &newrlim) == -1)
     {
        if (errno != EPERM) {
           fprintf(stderr, "setrlimit changing hardlimit must set errno=EPERM\n");
           exit(1);
        }
     }
     else
     {
          fprintf(stderr, "setrlimit changing hardlimit must return -1\n");
          exit(1);
     }
  
     newrlim.rlim_cur = oldrlim.rlim_cur / 2;
     newrlim.rlim_max = oldrlim.rlim_max;
       
     if (setrlimit(RLIMIT_NOFILE, &newrlim) < 0)
     {
        perror("setrlimit");
        exit(1);
     }
       
     if (getrlimit(RLIMIT_NOFILE, &newrlim) < 0)
     {
        perror("getrlimit");
        exit(1);
     }
  
     if (newrlim.rlim_cur != oldrlim.rlim_cur / 2)
     {
        fprintf(stderr, "rlim_cur is %llu (should be %llu)\n",
                (unsigned long long)newrlim.rlim_cur,
                (unsigned long long)oldrlim.rlim_cur / 2);
     }
  
     if (newrlim.rlim_max != oldrlim.rlim_max)
     {
        fprintf(stderr, "rlim_max is %llu (should be %llu)\n",
                (unsigned long long)newrlim.rlim_max,
                (unsigned long long)oldrlim.rlim_max);
     }
  
     newrlim.rlim_cur -= 3; /* allow for stdin, stdout and stderr */
  
     while (newrlim.rlim_cur-- > 0)
     {
        if (open("/dev/null", O_RDONLY) < 0)
        {
           perror("open");
        }
     }
  
     if ((fd = open("/dev/null", O_RDONLY)) >= 0)
     {
        fprintf(stderr, "open succeeded with fd %d - it should have failed!\n", fd);
     }
     else if (errno != EMFILE)
     {
        perror("open");
     }
  
     if (setrlimit(RLIMIT_NOFILE, NULL) != -1  || errno != EFAULT)
     {
        fprintf(stderr, "setrlimit non addressable arg2 must set errno=EFAULT\n");
        exit(1);
     }
     
     exit(0);
  }
  