xref: /freebsd/bin/sleep/sleep.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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 #include <capsicum_helpers.h>
31 #include <err.h>
32 #include <errno.h>
33 #include <limits.h>
34 #include <signal.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <time.h>
38 
39 static void usage(void) __dead2;
40 
41 static volatile sig_atomic_t report_requested;
42 static void
43 report_request(int signo __unused)
44 {
45 
46 	report_requested = 1;
47 }
48 
49 int
50 main(int argc, char *argv[])
51 {
52 	struct timespec time_to_sleep;
53 	double d, seconds;
54 	time_t original;
55 	char unit;
56 	char buf[2];
57 	int i, matches;
58 
59 	if (caph_limit_stdio() < 0 || caph_enter() < 0)
60 		err(1, "capsicum");
61 
62 	if (argc < 2)
63 		usage();
64 
65 	seconds = 0;
66 	for (i = 1; i < argc; i++) {
67 		matches = sscanf(argv[i], "%lf%c%1s", &d, &unit, buf);
68 		if (matches == 2)
69 			switch(unit) {
70 			case 'd':
71 				d *= 24;
72 				/* FALLTHROUGH */
73 			case 'h':
74 				d *= 60;
75 				/* FALLTHROUGH */
76 			case 'm':
77 				d *= 60;
78 				/* FALLTHROUGH */
79 			case 's':
80 				break;
81 			default:
82 				usage();
83 			}
84 		else
85 			if (matches != 1)
86 				usage();
87 		seconds += d;
88 	}
89 	if (seconds > INT_MAX)
90 		usage();
91 	if (seconds <= 0)
92 		return (0);
93 	original = time_to_sleep.tv_sec = (time_t)seconds;
94 	time_to_sleep.tv_nsec = 1e9 * (seconds - time_to_sleep.tv_sec);
95 
96 	signal(SIGINFO, report_request);
97 
98 	/*
99 	 * Note: [EINTR] is supposed to happen only when a signal was handled
100 	 * but the kernel also returns it when a ptrace-based debugger
101 	 * attaches. This is a bug but it is hard to fix.
102 	 */
103 	while (nanosleep(&time_to_sleep, &time_to_sleep) != 0) {
104 		if (report_requested) {
105 			/* Reporting does not bother with nanoseconds. */
106 			warnx("about %d second(s) left out of the original %d",
107 			    (int)time_to_sleep.tv_sec, (int)original);
108 			report_requested = 0;
109 		} else if (errno != EINTR)
110 			err(1, "nanosleep");
111 	}
112 	return (0);
113 }
114 
115 static void
116 usage(void)
117 {
118 
119 	fprintf(stderr, "usage: sleep number[unit] ...\n");
120 	fprintf(stderr, "Unit can be 's' (seconds, the default), "
121 			"m (minutes), h (hours), or d (days).\n");
122 	exit(1);
123 }
124