ast_comparator/test/student_data/handout/shlab-handout/cases/reference_21_tsh.c
/*
 * sigtstp_handler - The kernel sends a SIGTSTP to the shell whenever
 *     the user types ctrl-z at the keyboard. Catch it and suspend the
 *     foreground job by sending it a SIGTSTP.  
 */
The kernel sends a SIGTSTP to the shell whenever
the user types ctrl-z at the keyboard. Catch it and suspend the
foreground job by sending it a SIGTSTP.
The kernel sends a SIGTSTP to the shell whenever the user types ctrl - z at the keyboard . Catch it and suspend the foreground job by sending it a SIGTSTP .
void sigtstp_handler(int sig) 
{
    int fpid = fgpid(jobs);
    if (fpid != 0)
    {
        kill(-fpid, SIGTSTP);  
    }    
    return;
}
void sigtstp_handler ( int sig ) { int fpid = fgpid ( jobs ) ; if ( fpid != 0 ) { kill ( - fpid , SIGTSTP ) ; } return ; }
sigtstp_handler - The kernel sends a SIGTSTP to the shell whenever
     the user types ctrl-z at the keyboard.
sigtstp_handler - The kernel sends a SIGTSTP to the shell whenever the user types ctrl - z at the keyboard .
// Check if any foreground process is running // Stopping signal of given process ID