xref: /minix/bin/sleep/sleep.c (revision 00b67f09)
1 /* $NetBSD: sleep.c,v 1.24 2011/08/29 14:51:19 joerg 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 1.24 2011/08/29 14:51:19 joerg 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 __dead static void alarmhandle(int);
57 __dead static void usage(void);
58 
59 static volatile sig_atomic_t report_requested;
60 static void
61 report_request(int signo __unused)
62 {
63 
64 	report_requested = 1;
65 }
66 
67 int
68 main(int argc, char *argv[])
69 {
70 	char *arg, *temp;
71 	double fval, ival, val;
72 	struct timespec ntime;
73 	time_t original;
74 	int ch, fracflag, rv;
75 
76 	setprogname(argv[0]);
77 	(void)setlocale(LC_ALL, "");
78 
79 	(void)signal(SIGALRM, alarmhandle);
80 
81 	while ((ch = getopt(argc, argv, "")) != -1)
82 		switch(ch) {
83 		default:
84 			usage();
85 		}
86 	argc -= optind;
87 	argv += optind;
88 
89 	if (argc != 1)
90 		usage();
91 
92 	/*
93 	 * Okay, why not just use atof for everything? Why bother
94 	 * checking if there is a fraction in use? Because the old
95 	 * sleep handled the full range of integers, that's why, and a
96 	 * double can't handle a large long. This is fairly useless
97 	 * given how large a number a double can hold on most
98 	 * machines, but now we won't ever have trouble. If you want
99 	 * 1000000000.9 seconds of sleep, well, that's your
100 	 * problem. Why use an isdigit() check instead of checking for
101 	 * a period? Because doing it this way means locales will be
102 	 * handled transparently by the atof code.
103 	 */
104 	fracflag = 0;
105 	arg = *argv;
106 	for (temp = arg; *temp != '\0'; temp++)
107 		if (!isdigit((unsigned char)*temp))
108 			fracflag++;
109 
110 	if (fracflag) {
111 		val = atof(arg);
112 		if (val <= 0)
113 			usage();
114 		ival = floor(val);
115 		fval = (1000000000 * (val-ival));
116 		ntime.tv_sec = ival;
117 		ntime.tv_nsec = fval;
118 	}
119 	else {
120 		ntime.tv_sec = atol(arg);
121 		if (ntime.tv_sec <= 0)
122 			return EXIT_SUCCESS;
123 		ntime.tv_nsec = 0;
124 	}
125 
126 	original = ntime.tv_sec;
127 	signal(SIGINFO, report_request);
128 	while ((rv = nanosleep(&ntime, &ntime)) != 0) {
129 		if (report_requested) {
130 		/* Reporting does not bother with nanoseconds. */
131 			warnx("about %d second(s) left out of the original %d",
132 			(int)ntime.tv_sec, (int)original);
133 			report_requested = 0;
134 		} else
135 			break;
136 	}
137 
138 	if (rv == -1)
139 		err(EXIT_FAILURE, "nanosleep failed");
140 
141 	return EXIT_SUCCESS;
142 	/* NOTREACHED */
143 }
144 
145 static void
146 usage(void)
147 {
148 	(void)fprintf(stderr, "usage: %s seconds\n", getprogname());
149 	exit(EXIT_FAILURE);
150 	/* NOTREACHED */
151 }
152 
153 /* ARGSUSED */
154 static void
155 alarmhandle(int i)
156 {
157 	_exit(EXIT_SUCCESS);
158 	/* NOTREACHED */
159 }
160