1 /*
2 * Copyright (c) 2014 Spectra Logic Corporation
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions, and the following disclaimer,
10 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * substantially similar to the "NO WARRANTY" disclaimer below
13 * ("Disclaimer") and any redistribution must be conditioned upon
14 * including a substantially similar Disclaimer requirement for further
15 * binary redistribution.
16 *
17 * NO WARRANTY
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGES.
29 *
30 * Authors: Alan Somers (Spectra Logic Corporation)
31 */
32
33 #include <errno.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <unistd.h>
37
38 #define RANDOM_MAX ((1U<<31) - 1)
39
main(int argc,char ** argv)40 int main(int argc, char** argv){
41 useconds_t max_usecs, usecs;
42 double frac;
43
44 if (argc != 2) {
45 printf("Usage: randsleep <max_microseconds>\n");
46 exit(2);
47 }
48
49 errno = 0;
50 max_usecs = (useconds_t)strtol(argv[1], NULL, 0);
51 if (errno != 0) {
52 perror("strtol");
53 exit(1);
54 }
55 srandomdev();
56 frac = (double)random() / (double)RANDOM_MAX;
57 usecs = (useconds_t)((double)max_usecs * frac);
58 usleep(usecs);
59
60 return (0);
61 }
62