jack2/example-clients/freewheel.c

/*
 *  freewheel - start/stop JACK "freewheeling" mode
 *
 *  Copyright (C) 2003 Paul Davis.
 *  
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <jack/jack.h>
#include <jack/transport.h>

char *package;				/* program name */
jack_client_t *client;
int onoff;

static void jack_shutdown(void *arg)
{
	fprintf(stderr, "JACK shut down, exiting ...\n");
	exit(1);
}

static void signal_handler(int sig)
{
	jack_client_close(client);
	fprintf(stderr, "signal received, exiting ...\n");
	exit(0);
}

static void parse_arguments(int argc, char *argv[])
{
	if (argc < 2) {
		fprintf(stderr, "usage: %s y|n\n", package);
		exit(9);
	}

	if (argv[1][0] == 'y' || argv[1][0] == 'Y' || argv[1][0] == '1') {
		onoff = 1;
	} else {
		onoff = 0;
	}
}

int 
main (int argc, char *argv[])
{
	parse_arguments (argc, argv);

	/* become a JACK client */
	if ((client = jack_client_open ("freewheel", JackNullOption, NULL)) == 0) {
		fprintf (stderr, "JACK server not running?\n");
		exit(1);
	}

	signal (SIGQUIT, signal_handler);
	signal (SIGTERM, signal_handler);
	signal (SIGHUP, signal_handler);
	signal (SIGINT, signal_handler);

	jack_on_shutdown (client, jack_shutdown, 0);

	if (jack_set_freewheel (client, onoff)) {
		fprintf (stderr, "failed to reset freewheel mode\n");
	}

	jack_client_close(client);
	return 0;
}