#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

int main ( void )
{
    int fd = open ( "/dev/watchdog", O_WRONLY );
    int ret = 0;

    if ( fd == -1 )
    {
        perror ( "watchdog" );
        exit ( EXIT_FAILURE );
    }

    while ( 1 )
    {
        ret = write ( fd, "\0", 1 );

        if ( ret != 1 )
        {
            ret = -1;
            break;
        }

        sleep ( 10 );
    }

    close ( fd );
    return ret;
}