src/bin/sleep/sleep.c

126 lines
3.3 KiB
C

/* $OpenBSD: sleep.c,v 1.29 2020/02/25 15:46:15 cheloha Exp $ */
/* $NetBSD: sleep.c,v 1.8 1995/03/21 09:11:11 cgd Exp $ */
/*
* Copyright (c) 1988, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/time.h>
#include <ctype.h>
#include <err.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
void alarmh(int);
void usage(void);
int
main(int argc, char *argv[])
{
struct timespec rqtp;
time_t t;
char *cp;
int ch, i;
if (pledge("stdio", NULL) == -1)
err(1, "pledge");
signal(SIGALRM, alarmh);
while ((ch = getopt(argc, argv, "")) != -1) {
switch(ch) {
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc != 1)
usage();
timespecclear(&rqtp);
/* Handle whole seconds. */
for (cp = argv[0]; *cp != '\0' && *cp != '.'; cp++) {
if (!isdigit((unsigned char)*cp))
errx(1, "seconds is invalid: %s", argv[0]);
t = (rqtp.tv_sec * 10) + (*cp - '0');
if (t / 10 != rqtp.tv_sec) /* overflow */
errx(1, "seconds is too large: %s", argv[0]);
rqtp.tv_sec = t;
}
/*
* Handle fractions of a second. The multiplier divides to zero
* after nine digits so anything more precise than a nanosecond is
* validated but not used.
*/
if (*cp == '.') {
i = 100000000;
for (cp++; *cp != '\0'; cp++) {
if (!isdigit((unsigned char)*cp))
errx(1, "seconds is invalid: %s", argv[0]);
rqtp.tv_nsec += (*cp - '0') * i;
i /= 10;
}
}
if (timespecisset(&rqtp)) {
if (nanosleep(&rqtp, NULL) == -1)
err(1, "nanosleep");
}
return 0;
}
void
usage(void)
{
fprintf(stderr, "usage: %s seconds\n", getprogname());
exit(1);
}
/*
* POSIX.1 says sleep(1) may exit with status zero upon receipt
* of SIGALRM.
*/
void
alarmh(int signo)
{
/*
* Always _exit(2) from signal handlers: exit(3) is not
* generally signal-safe.
*/
_exit(0);
}