Example 5: Using exec #include #include #include #include (1) (2) int main(void) { pid_t childpid; (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) childpid = fork(); if (childpid == -1) { perror ("Failed to fork"); return 1; } if (childpid == 0) { /* child code */ execl ("/bin/ls", "ls", "-1", NULL); perror ("Child failed to exec ls"); return 1; } if (childpid != wait (NULL)) { /* parent code */ perror ("Parent failed to wait due to signal or error"); return 1; } return 0; } a) What does the child execute after line 9? b) What process finishes first, parent or child