bin/sleep/sleep.c

   1 /* $NetBSD: sleep.c,v 1.24 2011/08/29 14:51:19 joerg Exp $ */
   2
   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 <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1988, 1993, 1994\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)sleep.c     8.3 (Berkeley) 4/2/94";
  41 #else
  42 __RCSID("$NetBSD: sleep.c,v 1.24 2011/08/29 14:51:19 joerg Exp $");
  43 #endif
  44 #endif /* not lint */
  45
  46 #include <ctype.h>
  47 #include <err.h>
  48 #include <locale.h>
  49 #include <math.h>
  50 #include <signal.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <time.h>
  54 #include <unistd.h>
  55
  56 __dead static void alarmhandle(int);
  57 __dead static void usage(void);
  58
  59 static volatile sig_atomic_t report_requested;
  60 static void
  61 report_request(int signo __unused)
  62 {
  63
  64         report_requested = 1;
  65 }
  66
  67 int
  68 main(int argc, char *argv[])
  69 {
  70         char *arg, *temp;
  71         double fval, ival, val;
  72         struct timespec ntime;
  73         time_t original;
  74         int ch, fracflag, rv;
  75
  76         setprogname(argv[0]);
  77         (void)setlocale(LC_ALL, "");
  78
  79         (void)signal(SIGALRM, alarmhandle);
  80
  81         while ((ch = getopt(argc, argv, "")) != -1)
  82                 switch(ch) {
  83                 default:
  84                         usage();
  85                 }
  86         argc -= optind;
  87         argv += optind;
  88
  89         if (argc != 1)
  90                 usage();
  91
  92         /*
  93          * Okay, why not just use atof for everything? Why bother
  94          * checking if there is a fraction in use? Because the old
  95          * sleep handled the full range of integers, that's why, and a
  96          * double can't handle a large long. This is fairly useless
  97          * given how large a number a double can hold on most
  98          * machines, but now we won't ever have trouble. If you want
  99          * 1000000000.9 seconds of sleep, well, that's your
 100          * problem. Why use an isdigit() check instead of checking for
 101          * a period? Because doing it this way means locales will be
 102          * handled transparently by the atof code.
 103          */
 104         fracflag = 0;
 105         arg = *argv;
 106         for (temp = arg; *temp != '\0'; temp++)
 107                 if (!isdigit((unsigned char)*temp))
 108                         fracflag++;
 109
 110         if (fracflag) {
 111                 val = atof(arg);
 112                 if (val <= 0)
 113                         usage();
 114                 ival = floor(val);
 115                 fval = (1000000000 * (val-ival));
 116                 ntime.tv_sec = ival;
 117                 ntime.tv_nsec = fval;
 118         }
 119         else {
 120                 ntime.tv_sec = atol(arg);
 121                 if (ntime.tv_sec <= 0)
 122                         return EXIT_SUCCESS;
 123                 ntime.tv_nsec = 0;
 124         }
 125
 126         original = ntime.tv_sec;
 127         signal(SIGINFO, report_request);
 128         while ((rv = nanosleep(&ntime, &ntime)) != 0) {
 129                 if (report_requested) {
 130                 /* Reporting does not bother with nanoseconds. */
 131                         warnx("about %d second(s) left out of the original %d",
 132                         (int)ntime.tv_sec, (int)original);
 133                         report_requested = 0;
 134                 } else
 135                         break;
 136         }
 137
 138         if (rv == -1)
 139                 err(EXIT_FAILURE, "nanosleep failed");
 140
 141         return EXIT_SUCCESS;
 142         /* NOTREACHED */
 143 }
 144
 145 static void
 146 usage(void)
 147 {
 148         (void)fprintf(stderr, "usage: %s seconds\n", getprogname());
 149         exit(EXIT_FAILURE);
 150         /* NOTREACHED */
 151 }
 152
 153 /* ARGSUSED */
 154 static void
 155 alarmhandle(int i)
 156 {
 157         _exit(EXIT_SUCCESS);
 158         /* NOTREACHED */
 159 }