xref: /freebsd/bin/sleep/sleep.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
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  * 3. 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
32 static 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
38 static char sccsid[] = "@(#)sleep.c	8.3 (Berkeley) 4/2/94";
39 #endif /* not lint */
40 #endif
41 #include <sys/cdefs.h>
42 #include <capsicum_helpers.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <limits.h>
46 #include <signal.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <time.h>
50 
51 static void usage(void) __dead2;
52 
53 static volatile sig_atomic_t report_requested;
54 static void
55 report_request(int signo __unused)
56 {
57 
58 	report_requested = 1;
59 }
60 
61 int
62 main(int argc, char *argv[])
63 {
64 	struct timespec time_to_sleep;
65 	double d, seconds;
66 	time_t original;
67 	char unit;
68 	char buf[2];
69 	int i, matches;
70 
71 	if (caph_limit_stdio() < 0 || caph_enter() < 0)
72 		err(1, "capsicum");
73 
74 	if (argc < 2)
75 		usage();
76 
77 	seconds = 0;
78 	for (i = 1; i < argc; i++) {
79 		matches = sscanf(argv[i], "%lf%c%1s", &d, &unit, buf);
80 		if (matches == 2)
81 			switch(unit) {
82 			case 'd':
83 				d *= 24;
84 				/* FALLTHROUGH */
85 			case 'h':
86 				d *= 60;
87 				/* FALLTHROUGH */
88 			case 'm':
89 				d *= 60;
90 				/* FALLTHROUGH */
91 			case 's':
92 				break;
93 			default:
94 				usage();
95 			}
96 		else
97 			if (matches != 1)
98 				usage();
99 		seconds += d;
100 	}
101 	if (seconds > INT_MAX)
102 		usage();
103 	if (seconds <= 0)
104 		return (0);
105 	original = time_to_sleep.tv_sec = (time_t)seconds;
106 	time_to_sleep.tv_nsec = 1e9 * (seconds - time_to_sleep.tv_sec);
107 
108 	signal(SIGINFO, report_request);
109 
110 	/*
111 	 * Note: [EINTR] is supposed to happen only when a signal was handled
112 	 * but the kernel also returns it when a ptrace-based debugger
113 	 * attaches. This is a bug but it is hard to fix.
114 	 */
115 	while (nanosleep(&time_to_sleep, &time_to_sleep) != 0) {
116 		if (report_requested) {
117 			/* Reporting does not bother with nanoseconds. */
118 			warnx("about %d second(s) left out of the original %d",
119 			    (int)time_to_sleep.tv_sec, (int)original);
120 			report_requested = 0;
121 		} else if (errno != EINTR)
122 			err(1, "nanosleep");
123 	}
124 	return (0);
125 }
126 
127 static void
128 usage(void)
129 {
130 
131 	fprintf(stderr, "usage: sleep number[unit] ...\n");
132 	fprintf(stderr, "Unit can be 's' (seconds, the default), "
133 			"m (minutes), h (hours), or d (days).\n");
134 	exit(1);
135 }
136