Code from WG0A to test RTS-based PTT at a low level

testserial.c

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

int main(int argc, char *argv[])
{
    int fd; 
    int RTS_flag;
    int error = 0;

    fd = open(argv[1],O_RDWR | O_NOCTTY );
    if (fd == -1 ) {    
        error = errno;          
        printf("Error opening device - %s : %s\n", argv[1], strerror(error));
        exit(error);                    
    }                                       
    RTS_flag = TIOCM_RTS;   
    if ( ioctl(fd,TIOCMBIS,&RTS_flag) == -1 ) {
        error = errno;                      
        printf("Error TIOCMBIS RTS device - %s : %s\n", argv[1], strerror(error));
        exit(error);                                        
    }                                                           
    printf("Press any key to disable PTT...");
    getchar();                          
    if ( ioctl(fd,TIOCMBIC,&RTS_flag) == -1 ) {
        error = errno;                                  
        printf("Error TIOCMBIC RTS device - %s : %s\n", argv[1], strerror(error));
        exit(error);                                                    
    }                                                                       
    close(fd);                                  

    return 0;
}