Svenska ElektronikForumet

Kod: Markera allt

/*
 * Serial line daemon program for executing command when button pressed.
 * The program uses the serial interface line CD (input: carrier detect)
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License.
 * See http://www.gnu.org/copyleft/ for details.
 *
 * Written by maxxflow, maxxflow.com
 * Based on sled by Guido Socher <guido@linuxfocus.org>
 */
#define VERINFO "version 0.1"
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>


static int fd = 0;

/* get the current state of the push button
 * and return it. */
int getpushbutton(int fd)
{
        int state;
        ioctl(fd, TIOCMGET, &state);    /* read interface */
        if (state & TIOCM_CAR) {
                return (1);
        }
        return (0);
}

void help()
{

printf("sswitch ");

#ifdef VERINFO
        puts(VERINFO);
#endif

printf("\n\
USAGE:   sswitch serial-device\n\
EXAMPLE: sswitch /dev/ttyS0\n\
\n\
");

exit(0);
}

int main(int argc, char **argv)
{
        int lstate = 0;
        int i = 0;
        pid_t pid;

        /* exactly one argument must be given */
        if (argc != 2)
                help();
        /* open device */
        fd = open(argv[1], O_RDWR | O_NDELAY);
        if (fd < 0) {
                fprintf(stderr, "ERROR: can not open \"%s\"\n", argv[1]);
                exit(2);
        }

        /* now we fork to background */
        if ((pid = fork())<0){
                perror("sswitch server fork");
                exit(1);
        }else if (pid > 0){
                /* parent dies */
                exit(0);
        }
        /* we are the child and run as a daemon */
        while(1){
                if (getpushbutton(fd)){
                        system("killall ogg123");
                }
                sleep(1);
        }
        /* we never get here */
        return (2);
}