timer.c

   1 /*
   2  * Timer.
   3  * Copyright (c) 2005-2007 by Michal Nazareicz <mina86@mina86.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  *
  18  * This is part of Tiny Applications Collection
  19  *   -> http://tinyapps.sourceforge.net/
  20  */
  21
  22 #define _POSIX_C_SOURCE 199309
  23 #include <unistd.h>
  24 #include <time.h>
  25 #include <signal.h>
  26 #include <stdio.h>
  27
  28 volatile sig_atomic_t signum = 0;
  29
  30 static void sighandler(int sig) {
  31         signum = sig;
  32 }
  33
  34
  35 int main(void) {
  36         struct timespec wait = { 0, 10000000 };
  37         unsigned int m = 0, ss = 0;
  38         char buffer[11] = "\r   0:00.00";
  39
  40 #ifdef SIGHUP
  41         signal(SIGHUP, sighandler);
  42 #endif
  43 #ifdef SIGINT
  44         signal(SIGINT, sighandler);
  45 #endif
  46 #ifdef SIGQUIT
  47         signal(SIGQUIT, sighandler);
  48 #endif
  49 #ifdef SIGPIPE
  50         signal(SIGPIPE, sighandler);
  51 #endif
  52 #ifdef SIGTERM
  53         signal(SIGTERM, sighandler);
  54 #endif
  55 #ifdef SIGSTOP
  56         signal(SIGSTOP, sighandler);
  57 #endif
  58 #ifdef SIGTSTP
  59         signal(SIGTSTP, sighandler);
  60 #endif
  61
  62         do {
  63                 if (write(1, buffer, 11)!=11) return 1;
  64
  65                 while (!signum && nanosleep(&wait, &wait));
  66                 if (signum) break;
  67                 wait.tv_nsec = 10000000;
  68
  69                 if ((ss = (ss+1)%6000)==0) {
  70                         ++m;
  71                         buffer[ 1] = m<1000 ? ' ' : (m/1000%10 + '0');
  72                         buffer[ 1] = m<100  ? ' ' : (m/100 %10 + '0');
  73                         buffer[ 3] = m<10   ? ' ' : (m/10  %10 + '0');
  74                         buffer[ 4] =                 m     %10 + '0';
  75                 }
  76
  77                 buffer[ 6] = ss/1000    + '0';
  78                 buffer[ 7] = ss/100 %10 + '0';
  79                 buffer[ 9] = ss/10  %10 + '0';
  80                 buffer[10] = ss     %10 + '0';
  81         } while (!signum);
  82
  83         printf("%07ld\n", 10000000 - wait.tv_nsec);
  84         return 0;
  85 }