openbsd-compat/regress/closefromtest.c

   1 /*
   2  * Copyright (c) 2006 Darren Tucker
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <sys/types.h>
  18 #include <sys/stat.h>
  19
  20 #include <fcntl.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24
  25 #define NUM_OPENS 10
  26
  27 void
  28 fail(char *msg)
  29 {
  30         fprintf(stderr, "closefrom: %s\n", msg);
  31         exit(1);
  32 }
  33
  34 int
  35 main(void)
  36 {
  37         int i, max, fds[NUM_OPENS];
  38         char buf[512];
  39
  40         for (i = 0; i < NUM_OPENS; i++)
  41                 if ((fds[i] = open("/dev/null", O_RDONLY)) == -1)
  42                         exit(0);        /* can't test */
  43         max = i - 1;
  44
  45         /* should close last fd only */
  46         closefrom(fds[max]);
  47         if (close(fds[max]) != -1)
  48                 fail("failed to close highest fd");
  49
  50         /* make sure we can still use remaining descriptors */
  51         for (i = 0; i < max; i++)
  52                 if (read(fds[i], buf, sizeof(buf)) == -1)
  53                         fail("closed descriptors it should not have");
  54
  55         /* should close all fds */
  56         closefrom(fds[0]);
  57         for (i = 0; i < NUM_OPENS; i++)
  58                 if (close(fds[i]) != -1)
  59                         fail("failed to close from lowest fd");
  60         return 0;
  61 }