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fcfa4c9589
Use return(0) for main() instead of exit(0). Makes it a wee bit smaller.
130 lines
3.5 KiB
C
130 lines
3.5 KiB
C
/*
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* Copyright (c) 1988, 1993, 1994
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if 0
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#ifndef lint
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static char const copyright[] =
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"@(#) Copyright (c) 1988, 1993, 1994\n\
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The Regents of the University of California. All rights reserved.\n";
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#endif /* not lint */
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#ifndef lint
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static char sccsid[] = "@(#)sleep.c 8.3 (Berkeley) 4/2/94";
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#endif /* not lint */
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#endif
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <ctype.h>
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#include <limits.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <time.h>
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#include <unistd.h>
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void usage(void);
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int
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main(int argc, char *argv[])
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{
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struct timespec time_to_sleep;
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long l;
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int neg;
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char *p;
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if (argc != 2) {
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usage();
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return(1);
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}
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p = argv[1];
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/* Skip over leading whitespaces. */
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while (isspace((unsigned char)*p))
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++p;
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/* Check for optional `+' or `-' sign. */
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neg = 0;
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if (*p == '-') {
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neg = 1;
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++p;
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if (!isdigit((unsigned char)*p) && *p != '.') {
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usage();
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return(1);
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}
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}
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else if (*p == '+')
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++p;
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/* Calculate seconds. */
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if (isdigit((unsigned char)*p)) {
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l = strtol(p, &p, 10);
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if (l > INT_MAX) {
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/*
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* Avoid overflow when `seconds' is huge. This assumes
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* that the maximum value for a time_t is >= INT_MAX.
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*/
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l = INT_MAX;
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}
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} else
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l = 0;
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time_to_sleep.tv_sec = (time_t)l;
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/* Calculate nanoseconds. */
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time_to_sleep.tv_nsec = 0;
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if (*p == '.') { /* Decimal point. */
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l = 100000000L;
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do {
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if (isdigit((unsigned char)*++p))
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time_to_sleep.tv_nsec += (*p - '0') * l;
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else
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break;
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l /= 10;
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} while (l);
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}
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if (!neg && (time_to_sleep.tv_sec > 0 || time_to_sleep.tv_nsec > 0))
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(void)nanosleep(&time_to_sleep, (struct timespec *)NULL);
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return(0);
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}
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void
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usage(void)
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{
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const char msg[] = "usage: sleep seconds\n";
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write(STDERR_FILENO, msg, sizeof(msg) - 1);
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}
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