bin/sleep/sleep.c

   1 /* $NetBSD: sleep.c,v 1.21 2007/08/18 00:41:52 hubertf 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 1.21 2007/08/18 00:41:52 hubertf 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 static void alarmhandle(int);
  57 static void usage(void);
  58 int main(int, char *[]);
  59
  60 int
  61 main(int argc, char *argv[])
  62 {
  63         char *arg, *temp;
  64         double fval, ival, val;
  65         struct timespec ntime;
  66         int ch, fracflag;
  67
  68         setprogname(argv[0]);
  69         (void)setlocale(LC_ALL, "");
  70
  71         (void)signal(SIGALRM, alarmhandle);
  72
  73         while ((ch = getopt(argc, argv, "")) != -1)
  74                 switch(ch) {
  75                 default:
  76                         usage();
  77                 }
  78         argc -= optind;
  79         argv += optind;
  80
  81         if (argc != 1)
  82                 usage();
  83
  84         /*
  85          * Okay, why not just use atof for everything? Why bother
  86          * checking if there is a fraction in use? Because the old
  87          * sleep handled the full range of integers, that's why, and a
  88          * double can't handle a large long. This is fairly useless
  89          * given how large a number a double can hold on most
  90          * machines, but now we won't ever have trouble. If you want
  91          * 1000000000.9 seconds of sleep, well, that's your
  92          * problem. Why use an isdigit() check instead of checking for
  93          * a period? Because doing it this way means locales will be
  94          * handled transparently by the atof code.
  95          */
  96         fracflag = 0;
  97         arg = *argv;
  98         for (temp = arg; *temp != '\0'; temp++)
  99                 if (!isdigit((unsigned char)*temp))
 100                         fracflag++;
 101
 102         if (fracflag) {
 103                 val = atof(arg);
 104                 if (val <= 0)
 105                         usage();
 106                 ival = floor(val);
 107                 fval = (1000000000 * (val-ival));
 108                 ntime.tv_sec = ival;
 109                 ntime.tv_nsec = fval;
 110         }
 111         else {
 112                 ntime.tv_sec = atol(arg);
 113                 if (ntime.tv_sec <= 0)
 114                         return EXIT_SUCCESS;
 115                 ntime.tv_nsec = 0;
 116         }
 117
 118         if (nanosleep(&ntime, NULL) == -1)
 119                 err(EXIT_FAILURE, "nanosleep failed");
 120
 121         return EXIT_SUCCESS;
 122         /* NOTREACHED */
 123 }
 124
 125 void
 126 usage(void)
 127 {
 128         (void)fprintf(stderr, "usage: %s seconds\n", getprogname());
 129         exit(EXIT_FAILURE);
 130         /* NOTREACHED */
 131 }
 132
 133 /* ARGSUSED */
 134 void
 135 alarmhandle(int i)
 136 {
 137         _exit(EXIT_SUCCESS);
 138         /* NOTREACHED */
 139 }