How to Execute Shell Script in C Programming, Receive Feedback and Processor ID, and Close Process

Question

I am writing a program that needs to fire another program for a number of seconds, then close it.

Feedback from the program's console would be useful, if possible.

I imagine I would close the program by retrieving the pid from the child process and running a pkill?

What would be the best way to go about this?

Thanks in advance

EDIT BY OP

void mountAd(char* adFilePath){

    char* mountPoint = getNextAvailableMount();

    // Set Playlist ready to be played
    editPlaylist(mountPoint, adFilePath);

    // Fork process and fire up ezstream
    int pid = fork();

    if(pid == 0){
        puts ("Child Process Here\n");
        execl ("/usr/local/bin/ezstream","/usr/local/bin/ezstream", "-c", "/home/hearme/radio/_test_adverts/advert01.xml", NULL);
        perror("execl");

    } else {
        puts ("Parent Process Here\n");
    }

    // Advised sleep for 3 seconds until ezstream has started
    sleep(3);

    // More stuff to do here later

    kill(pid, SIGTERM);
    waitpid(pid, NULL, 0);

}

Answer 1

Something like this should work:

pid = fork();
if (pid < 0)
    /* fork failed, error handling here */

if (pid == 0) {
    /* we are the child, exec process */
    execl(...);

    /* this is only reached if execl fails */
    perror("execl");

    /* do not use exit() here, do not return from main() */
    _Exit(EXIT_FAILURE);
}

/* we are the parent */
sleep(duration);

kill(pid, SIGKILL);

/* use wait/waitpid/waitid as needed */
waitpid(pid, NULL, 0);

Notice that this does not correctly perform error checking for the case when the program you want to run cannot be found or executed, a more elaborate scheme is needed for that case, if you are interested I could elaborate.