timer.c

/*
 * Timer.
 * Copyright (c) 2005-2007 by Michal Nazareicz (mina86/AT/mina86.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This software is OSI Certified Open Source Software.
 * OSI Certified is a certification mark of the Open Source Initiative.
 *
 * This is part of Tiny Applications Collection
 *   -> http://tinyapps.sourceforge.net/
 */

#define _POSIX_C_SOURCE 199309
#include <unistd.h>
#include <time.h>
#include <signal.h>
#include <stdio.h>

volatile sig_atomic_t signum = 0;

static void sighandler(int sig) {
	signum = sig;
}


int main(void) {
	struct timespec wait = { 0, 10000000 };
	unsigned int m = 0, ss = 0;
	char buffer[11] = "\r   0:00.00";

#ifdef SIGHUP
	signal(SIGHUP, sighandler);
#endif
#ifdef SIGINT
	signal(SIGINT, sighandler);
#endif
#ifdef SIGQUIT
	signal(SIGQUIT, sighandler);
#endif
#ifdef SIGPIPE
	signal(SIGPIPE, sighandler);
#endif
#ifdef SIGTERM
	signal(SIGTERM, sighandler);
#endif
#ifdef SIGSTOP
	signal(SIGSTOP, sighandler);
#endif
#ifdef SIGTSTP
	signal(SIGTSTP, sighandler);
#endif

	do {
		if (write(1, buffer, 11)!=11) return 1;

		while (!signum && nanosleep(&wait, &wait));
		if (signum) break;
		wait.tv_nsec = 10000000;

		if ((ss = (ss+1)%6000)==0) {
			++m;
			buffer[ 1] = m<1000 ? ' ' : (m/1000%10 + '0');
			buffer[ 1] = m<100  ? ' ' : (m/100 %10 + '0');
			buffer[ 3] = m<10   ? ' ' : (m/10  %10 + '0');
			buffer[ 4] =                 m     %10 + '0';
		}

		buffer[ 6] = ss/1000    + '0';
		buffer[ 7] = ss/100 %10 + '0';
		buffer[ 9] = ss/10  %10 + '0';
		buffer[10] = ss     %10 + '0';
	} while (!signum);

	printf("%07ld\n", 10000000 - wait.tv_nsec);
	return 0;
}