/*Spiros Ioannou 1997 (sivann a-t softlab.ece.ntua.gr) 
 * Change rs-232 signals  */

#include <fcntl.h>
#include <sys/termios.h>
#include <stdio.h>
#include <sys/types.h>

main(int argc,char *argv[])
{
      int     fd;
      int     dtr=0;
      int     i=1;
      int     c=-1;
if (argc != 3 ) {printf("\nUsage: %s [tty] [on|off]\n\n",argv[0]);exit(1);}

        if((fd = open(argv[1], 0)) == -1) {
                fprintf(stderr, "Cant open device\n");
                exit(1);
        }
 if (!strcmp(argv[2],"on"))
 {
     c=c|TIOCM_DTR;
     
 } 
 else c=c&!TIOCM_DTR;
printf("Toggling DTR\n");
ioctl(fd, TIOCMSET, &c);
ioctl(fd, TIOCMGET, &c);
printf("NEW state:%d\n",c);
if (c&TIOCM_RTS) printf("RTS\n");
if (c&TIOCM_LE) printf("Line Enable\n");
if (c&TIOCM_DTR) printf("DTR\n");
if (c&TIOCM_CAR) printf("CARRIER DETECT\n");
if (c&TIOCM_DSR) printf("DSR\n");
if (c&TIOCM_CTS) printf("CTS\n");
if (c&TIOCM_DSR) printf("DSR\n");
if (c&TIOCM_RNG) printf("RING!\n");

close(fd);
}