tools/testing/selftests/proc/fd-002-posix-eq.c

   1 /*
   2  * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
   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 // Test that open(/proc/*/fd/*) opens the same file.
  17 #undef NDEBUG
  18 #include <assert.h>
  19 #include <stdio.h>
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <fcntl.h>
  23 #include <unistd.h>
  24
  25 int main(void)
  26 {
  27         int fd0, fd1, fd2;
  28         struct stat st0, st1, st2;
  29         char buf[64];
  30         int rv;
  31
  32         fd0 = open("/", O_DIRECTORY|O_RDONLY);
  33         assert(fd0 >= 0);
  34
  35         snprintf(buf, sizeof(buf), "/proc/self/fd/%u", fd0);
  36         fd1 = open(buf, O_RDONLY);
  37         assert(fd1 >= 0);
  38
  39         snprintf(buf, sizeof(buf), "/proc/thread-self/fd/%u", fd0);
  40         fd2 = open(buf, O_RDONLY);
  41         assert(fd2 >= 0);
  42
  43         rv = fstat(fd0, &st0);
  44         assert(rv == 0);
  45         rv = fstat(fd1, &st1);
  46         assert(rv == 0);
  47         rv = fstat(fd2, &st2);
  48         assert(rv == 0);
  49
  50         assert(st0.st_dev == st1.st_dev);
  51         assert(st0.st_ino == st1.st_ino);
  52
  53         assert(st0.st_dev == st2.st_dev);
  54         assert(st0.st_ino == st2.st_ino);
  55
  56         return 0;
  57 }