xref: /src/bin/sleep/sleep.c (revision f4eccc3add7b91532396970913792fa264fc5430)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 <capsicum_helpers.h>
33 #include <err.h>
34 #include <errno.h>
35 #include <limits.h>
36 #include <math.h>
37 #include <signal.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <time.h>
41 #include <unistd.h>
42 
43 static volatile sig_atomic_t report_requested;
44 
45 static void
report_request(int signo __unused)46 report_request(int signo __unused)
47 {
48 	report_requested = 1;
49 }
50 
51 static void __dead2
usage(void)52 usage(void)
53 {
54 	fprintf(stderr, "usage: sleep number[unit] [...]\n"
55 	    "Unit can be 's' (seconds, the default), "
56 	    "m (minutes), h (hours), or d (days).\n");
57 	exit(1);
58 }
59 
60 static double
parse_interval(const char * arg)61 parse_interval(const char *arg)
62 {
63 	double num;
64 	char unit, extra;
65 
66 	switch (sscanf(arg, "%lf%c%c", &num, &unit, &extra)) {
67 	case 2:
68 		switch (unit) {
69 		case 'd':
70 			num *= 24;
71 			/* FALLTHROUGH */
72 		case 'h':
73 			num *= 60;
74 			/* FALLTHROUGH */
75 		case 'm':
76 			num *= 60;
77 			/* FALLTHROUGH */
78 		case 's':
79 			if (!isnan(num))
80 				return (num);
81 		}
82 		break;
83 	case 1:
84 		if (!isnan(num))
85 			return (num);
86 	}
87 	warnx("invalid time interval: %s", arg);
88 	return (INFINITY);
89 }
90 
91 int
main(int argc,char * argv[])92 main(int argc, char *argv[])
93 {
94 	struct timespec time_to_sleep;
95 	double seconds;
96 	time_t original;
97 
98 	if (caph_limit_stdio() < 0 || caph_enter() < 0)
99 		err(1, "capsicum");
100 
101 	while (getopt(argc, argv, "") != -1)
102 		usage();
103 	argc -= optind;
104 	argv += optind;
105 	if (argc < 1)
106 		usage();
107 
108 	seconds = 0;
109 	while (argc--)
110 		seconds += parse_interval(*argv++);
111 	if (seconds > INT_MAX)
112 		usage();
113 	if (seconds < 1e-9)
114 		exit(0);
115 	original = time_to_sleep.tv_sec = (time_t)seconds;
116 	time_to_sleep.tv_nsec = 1e9 * (seconds - time_to_sleep.tv_sec);
117 
118 	signal(SIGINFO, report_request);
119 
120 	while (nanosleep(&time_to_sleep, &time_to_sleep) != 0) {
121 		if (errno != EINTR)
122 			err(1, "nanosleep");
123 		if (report_requested) {
124 			/* Reporting does not bother with nanoseconds. */
125 			warnx("about %ld second(s) left out of the original %ld",
126 			    (long)time_to_sleep.tv_sec, (long)original);
127 			report_requested = 0;
128 		}
129 	}
130 
131 	exit(0);
132 }
133