#include <unistd.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>

char *procname;

int open_port (char *device)
{
        int fd;

        fd=open(device,O_RDWR|O_NOCTTY|O_NDELAY);
        if (fd == -1)
                perror(procname);
        else
                fcntl(fd,F_SETFL,0);

        return(fd);
}

void ring (int fd)
{
        int status;

        if (ioctl(fd,TIOCMGET,&status))
                perror(procname);

        status|=TIOCM_RNG;

        if (ioctl(fd,TIOCMSET,&status))
                perror(procname);
}

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

        procname=argv[0];
        if (argc != 2)
        {
                fprintf(stderr,"%s: Wrong number of arguments!\n",argv[0]);
                exit(1);
        }
        res=open_port(argv[1]);
        if (res == -1)
        {
                exit(2);
        }
        ring(res);
        close(res);

        exit(0);
}