xref: /netbsd-src/bin/sleep/sleep.c (revision 274254cdae52594c1aa480a736aef78313d15c9c)
1 /* $NetBSD: sleep.c,v 1.22 2008/07/20 00:52:40 lukem Exp $ */
2 
3 /*
4  * Copyright (c) 1988, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1988, 1993, 1994\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)sleep.c	8.3 (Berkeley) 4/2/94";
41 #else
42 __RCSID("$NetBSD: sleep.c,v 1.22 2008/07/20 00:52:40 lukem Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #include <ctype.h>
47 #include <err.h>
48 #include <locale.h>
49 #include <math.h>
50 #include <signal.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <time.h>
54 #include <unistd.h>
55 
56 static void alarmhandle(int);
57 static void usage(void);
58 int main(int, char *[]);
59 
60 int
61 main(int argc, char *argv[])
62 {
63 	char *arg, *temp;
64 	double fval, ival, val;
65 	struct timespec ntime;
66 	int ch, fracflag;
67 
68 	setprogname(argv[0]);
69 	(void)setlocale(LC_ALL, "");
70 
71 	(void)signal(SIGALRM, alarmhandle);
72 
73 	while ((ch = getopt(argc, argv, "")) != -1)
74 		switch(ch) {
75 		default:
76 			usage();
77 		}
78 	argc -= optind;
79 	argv += optind;
80 
81 	if (argc != 1)
82 		usage();
83 
84 	/*
85 	 * Okay, why not just use atof for everything? Why bother
86 	 * checking if there is a fraction in use? Because the old
87 	 * sleep handled the full range of integers, that's why, and a
88 	 * double can't handle a large long. This is fairly useless
89 	 * given how large a number a double can hold on most
90 	 * machines, but now we won't ever have trouble. If you want
91 	 * 1000000000.9 seconds of sleep, well, that's your
92 	 * problem. Why use an isdigit() check instead of checking for
93 	 * a period? Because doing it this way means locales will be
94 	 * handled transparently by the atof code.
95 	 */
96 	fracflag = 0;
97 	arg = *argv;
98 	for (temp = arg; *temp != '\0'; temp++)
99 		if (!isdigit((unsigned char)*temp))
100 			fracflag++;
101 
102 	if (fracflag) {
103 		val = atof(arg);
104 		if (val <= 0)
105 			usage();
106 		ival = floor(val);
107 		fval = (1000000000 * (val-ival));
108 		ntime.tv_sec = ival;
109 		ntime.tv_nsec = fval;
110 	}
111 	else {
112 		ntime.tv_sec = atol(arg);
113 		if (ntime.tv_sec <= 0)
114 			return EXIT_SUCCESS;
115 		ntime.tv_nsec = 0;
116 	}
117 
118 	if (nanosleep(&ntime, NULL) == -1)
119 		err(EXIT_FAILURE, "nanosleep failed");
120 
121 	return EXIT_SUCCESS;
122 	/* NOTREACHED */
123 }
124 
125 void
126 usage(void)
127 {
128 	(void)fprintf(stderr, "usage: %s seconds\n", getprogname());
129 	exit(EXIT_FAILURE);
130 	/* NOTREACHED */
131 }
132 
133 /* ARGSUSED */
134 void
135 alarmhandle(int i)
136 {
137 	_exit(EXIT_SUCCESS);
138 	/* NOTREACHED */
139 }
140