Shell Programming and Scripting

#include <stdio.h>
#include <unistd.h>
#define TTY_NAME_MAX        32
#define STDIN_FILENO    0   /* Standard input.  */

int main(void) {
    int     ret = 0;
    char    local_device_file[TTY_NAME_MAX];
        printf("\npid = %d\n",getpid());
        ret = ttyname_r(STDIN_FILENO, local_device_file, TTY_NAME_MAX);
        printf("ret = %d, local_device_file = %s\n",ret,local_device_file);
        return 0;
}

echo "running test script"
/users/ghonnaia/tty

bgl-xdm-140:199> ./test_script
running test script
pid = 6249
ret = 0, local_device_file = /dev/pts/399

echo "running test script"
/users/ghonnaia/tty &

bgl-xdm-140:197> ./test_script
running test script
bgl-xdm-140:198> 
pid = 5951
ret = 25, local_device_file =

#define ENOTTY          25      /* Not a typewriter */