xref: /openbsd-src/bin/sleep/sleep.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: sleep.c,v 1.18 2009/02/13 20:39:58 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 #ifndef lint
34 static char copyright[] =
35 "@(#) Copyright (c) 1988, 1993, 1994\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)sleep.c	8.3 (Berkeley) 4/2/94";
42 #else
43 static char rcsid[] = "$OpenBSD: sleep.c,v 1.18 2009/02/13 20:39:58 deraadt Exp $";
44 #endif
45 #endif /* not lint */
46 
47 #include <ctype.h>
48 #include <errno.h>
49 #include <locale.h>
50 #include <signal.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <time.h>
54 #include <unistd.h>
55 
56 extern char *__progname;
57 
58 void usage(void);
59 void alarmh(int);
60 
61 int
62 main(int argc, char *argv[])
63 {
64 	int ch;
65 	time_t secs = 0, t;
66 	char *cp;
67 	long nsecs = 0;
68 	struct timespec rqtp;
69 	int i;
70 
71 	setlocale(LC_ALL, "");
72 
73 	signal(SIGALRM, alarmh);
74 
75 	while ((ch = getopt(argc, argv, "")) != -1)
76 		switch(ch) {
77 		default:
78 			usage();
79 		}
80 	argc -= optind;
81 	argv += optind;
82 
83 	if (argc != 1)
84 		usage();
85 
86 	cp = *argv;
87 	while ((*cp != '\0') && (*cp != '.')) {
88 		if (!isdigit(*cp))
89 			usage();
90 		t = (secs * 10) + (*cp++ - '0');
91 		if (t / 10 != secs)	/* oflow */
92 			return (EINVAL);
93 		secs = t;
94 	}
95 
96 	/* Handle fractions of a second */
97 	if (*cp == '.') {
98 		cp++;
99 		for (i = 100000000; i > 0; i /= 10) {
100 			if (*cp == '\0')
101 				break;
102 			if (!isdigit(*cp))
103 				usage();
104 			nsecs += (*cp++ - '0') * i;
105 		}
106 
107 		/*
108 		 * We parse all the way down to nanoseconds
109 		 * in the above for loop. Be pedantic about
110 		 * checking the rest of the argument.
111 		 */
112 		while (*cp != '\0') {
113 			if (!isdigit(*cp++))
114 				usage();
115 		}
116 	}
117 
118 	rqtp.tv_sec = secs;
119 	rqtp.tv_nsec = nsecs;
120 
121 	if ((secs > 0) || (nsecs > 0))
122 		if (nanosleep(&rqtp, NULL))
123 			return (errno);
124 	return (0);
125 }
126 
127 void
128 usage(void)
129 {
130 	(void)fprintf(stderr, "usage: %s seconds\n", __progname);
131 	exit(1);
132 }
133 
134 /*
135  * POSIX 1003.2 says sleep should exit with 0 return code on reception
136  * of SIGALRM.
137  */
138 /* ARGSUSED */
139 void
140 alarmh(int signo)
141 {
142 	/*
143 	 * exit() flushes stdio buffers, which is not legal in a signal
144 	 * handler. Use _exit().
145 	 */
146 	_exit(0);
147 }
148