SIGTSTP

SIGTSTP is a signal in a Unix computer system that tells a program to stop temporarily. On POSIX-compliant platforms, SIGTSTP is the signal sent to a process by its controlling terminal when the user requests that the process be suspended. The symbolic constant for SIGTSTP is defined in the header file signal.h. Symbolic signal names are used because signal numbers can vary across platforms.

Etymology

SIG is a common prefix for signal names. TSTP is an abbreviation for tty stop, indicating that stop has been typed at the tty (the controlling terminal of the process). (Tty is itself an abbreviation for teletypewriter, an archaic type of computer terminal.)

Usage

SIGTSTP is sent to a process by its controlling terminal when the user presses the special SUSP key combination (usually control-Z). By default, SIGTSTP causes the process receiving it to stop until a SIGCONT signal is received. Unlike the similar SIGSTOP signal, a process can register a signal handler for or ignore SIGTSTP.