What is the difference between SIGSTOP and SIGTSTP?
Both signals are designed to suspend a process which will be eventually resumed with SIGCONT. The main differences between them are: SIGSTOP is a signal sent programmatically (eg: kill -STOP pid ) while SIGTSTP (for signal – terminal stop) may also be sent through the tty driver by a user typing on a keyboard, usually Control–Z. SIGSTOP cannot be ignored. SIGTSTP might be.