xref: /freebsd/bin/sleep/sleep.c (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
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 #endif
38 #include <sys/cdefs.h>
39 #include <capsicum_helpers.h>
40 #include <err.h>
41 #include <errno.h>
42 #include <limits.h>
43 #include <signal.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <time.h>
47 
48 static void usage(void) __dead2;
49 
50 static volatile sig_atomic_t report_requested;
51 static void
52 report_request(int signo __unused)
53 {
54 
55 	report_requested = 1;
56 }
57 
58 int
59 main(int argc, char *argv[])
60 {
61 	struct timespec time_to_sleep;
62 	double d, seconds;
63 	time_t original;
64 	char unit;
65 	char buf[2];
66 	int i, matches;
67 
68 	if (caph_limit_stdio() < 0 || caph_enter() < 0)
69 		err(1, "capsicum");
70 
71 	if (argc < 2)
72 		usage();
73 
74 	seconds = 0;
75 	for (i = 1; i < argc; i++) {
76 		matches = sscanf(argv[i], "%lf%c%1s", &d, &unit, buf);
77 		if (matches == 2)
78 			switch(unit) {
79 			case 'd':
80 				d *= 24;
81 				/* FALLTHROUGH */
82 			case 'h':
83 				d *= 60;
84 				/* FALLTHROUGH */
85 			case 'm':
86 				d *= 60;
87 				/* FALLTHROUGH */
88 			case 's':
89 				break;
90 			default:
91 				usage();
92 			}
93 		else
94 			if (matches != 1)
95 				usage();
96 		seconds += d;
97 	}
98 	if (seconds > INT_MAX)
99 		usage();
100 	if (seconds <= 0)
101 		return (0);
102 	original = time_to_sleep.tv_sec = (time_t)seconds;
103 	time_to_sleep.tv_nsec = 1e9 * (seconds - time_to_sleep.tv_sec);
104 
105 	signal(SIGINFO, report_request);
106 
107 	/*
108 	 * Note: [EINTR] is supposed to happen only when a signal was handled
109 	 * but the kernel also returns it when a ptrace-based debugger
110 	 * attaches. This is a bug but it is hard to fix.
111 	 */
112 	while (nanosleep(&time_to_sleep, &time_to_sleep) != 0) {
113 		if (report_requested) {
114 			/* Reporting does not bother with nanoseconds. */
115 			warnx("about %d second(s) left out of the original %d",
116 			    (int)time_to_sleep.tv_sec, (int)original);
117 			report_requested = 0;
118 		} else if (errno != EINTR)
119 			err(1, "nanosleep");
120 	}
121 	return (0);
122 }
123 
124 static void
125 usage(void)
126 {
127 
128 	fprintf(stderr, "usage: sleep number[unit] ...\n");
129 	fprintf(stderr, "Unit can be 's' (seconds, the default), "
130 			"m (minutes), h (hours), or d (days).\n");
131 	exit(1);
132 }
133