xref: /openbsd-src/bin/sleep/sleep.c (revision d13be5d47e4149db2549a9828e244d59dbc43f15)
1 /*	$OpenBSD: sleep.c,v 1.19 2009/10/27 23:59:22 deraadt Exp $	*/
2 /*	$NetBSD: sleep.c,v 1.8 1995/03/21 09:11:11 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1988, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <ctype.h>
34 #include <errno.h>
35 #include <locale.h>
36 #include <signal.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <time.h>
40 #include <unistd.h>
41 
42 extern char *__progname;
43 
44 void usage(void);
45 void alarmh(int);
46 
47 int
48 main(int argc, char *argv[])
49 {
50 	int ch;
51 	time_t secs = 0, t;
52 	char *cp;
53 	long nsecs = 0;
54 	struct timespec rqtp;
55 	int i;
56 
57 	setlocale(LC_ALL, "");
58 
59 	signal(SIGALRM, alarmh);
60 
61 	while ((ch = getopt(argc, argv, "")) != -1)
62 		switch(ch) {
63 		default:
64 			usage();
65 		}
66 	argc -= optind;
67 	argv += optind;
68 
69 	if (argc != 1)
70 		usage();
71 
72 	cp = *argv;
73 	while ((*cp != '\0') && (*cp != '.')) {
74 		if (!isdigit(*cp))
75 			usage();
76 		t = (secs * 10) + (*cp++ - '0');
77 		if (t / 10 != secs)	/* oflow */
78 			return (EINVAL);
79 		secs = t;
80 	}
81 
82 	/* Handle fractions of a second */
83 	if (*cp == '.') {
84 		cp++;
85 		for (i = 100000000; i > 0; i /= 10) {
86 			if (*cp == '\0')
87 				break;
88 			if (!isdigit(*cp))
89 				usage();
90 			nsecs += (*cp++ - '0') * i;
91 		}
92 
93 		/*
94 		 * We parse all the way down to nanoseconds
95 		 * in the above for loop. Be pedantic about
96 		 * checking the rest of the argument.
97 		 */
98 		while (*cp != '\0') {
99 			if (!isdigit(*cp++))
100 				usage();
101 		}
102 	}
103 
104 	rqtp.tv_sec = secs;
105 	rqtp.tv_nsec = nsecs;
106 
107 	if ((secs > 0) || (nsecs > 0))
108 		if (nanosleep(&rqtp, NULL))
109 			return (errno);
110 	return (0);
111 }
112 
113 void
114 usage(void)
115 {
116 	(void)fprintf(stderr, "usage: %s seconds\n", __progname);
117 	exit(1);
118 }
119 
120 /*
121  * POSIX 1003.2 says sleep should exit with 0 return code on reception
122  * of SIGALRM.
123  */
124 /* ARGSUSED */
125 void
126 alarmh(int signo)
127 {
128 	/*
129 	 * exit() flushes stdio buffers, which is not legal in a signal
130 	 * handler. Use _exit().
131 	 */
132 	_exit(0);
133 }
134