sleep.c revision 210749 
1/*-
2 * Copyright (c) 1988, 1993, 1994
3 *	The Regents of the University of California.  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 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#if 0
31#ifndef lint
32static char const copyright[] =
33"@(#) Copyright (c) 1988, 1993, 1994\n\
34	The Regents of the University of California.  All rights reserved.\n";
35#endif /* not lint */
36
37#ifndef lint
38static char sccsid[] = "@(#)sleep.c	8.3 (Berkeley) 4/2/94";
39#endif /* not lint */
40#endif
41#include <sys/cdefs.h>
42__FBSDID("$FreeBSD: head/bin/sleep/sleep.c 210749 2010-08-02 10:57:56Z kib $");
43
44#include <ctype.h>
45#include <err.h>
46#include <limits.h>
47#include <signal.h>
48#include <stdint.h>
49#include <stdio.h>
50#include <stdlib.h>
51#include <time.h>
52
53static void usage(void);
54
55static volatile sig_atomic_t report_requested;
56static void
57report_request(int signo __unused)
58{
59
60	report_requested = 1;
61}
62
63int
64main(int argc, char *argv[])
65{
66	struct timespec time_to_sleep;
67	double d;
68	time_t original;
69	char buf[2];
70
71	if (argc != 2)
72		usage();
73
74	if (sscanf(argv[1], "%lf%1s", &d, buf) != 1)
75		usage();
76	if (d > INT_MAX)
77		usage();
78	if (d <= 0)
79		return (0);
80	original = time_to_sleep.tv_sec = (time_t)d;
81	time_to_sleep.tv_nsec = 1e9 * (d - time_to_sleep.tv_sec);
82
83	signal(SIGINFO, report_request);
84	while (nanosleep(&time_to_sleep, &time_to_sleep) != 0) {
85		if (report_requested) {
86			/* Reporting does not bother with nanoseconds. */
87			warnx("about %d second(s) left out of the original %d",
88			    (int)time_to_sleep.tv_sec, (int)original);
89			report_requested = 0;
90		} else
91			break;
92	}
93	return (0);
94}
95
96static void
97usage(void)
98{
99
100	fprintf(stderr, "usage: sleep seconds\n");
101	exit(1);
102}
103