tools/reorder/rseed.c

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 /*
   6
   7   A program that reads /dev/random to produce a seed for srand(3).
   8
   9  */
  10
  11 #include <stdio.h>
  12 #include <fcntl.h>
  13
  14 int
  15 main(int argc, char *argv[])
  16 {
  17     int fd, ok, seed = 0;
  18
  19     fd = open("/dev/random", O_RDONLY);
  20     if (fd < 0) {
  21         perror("/dev/random");
  22         return 1;
  23     }
  24
  25     ok = read(fd, &seed, sizeof seed);
  26     if (ok > 0)
  27         printf("%d\n", seed);
  28     else
  29         perror("/dev/random");
  30
  31     close(fd);
  32     return 0;
  33 }