Signals

Signals are software-level commuications between processes. The two actions are handled by the kernel.

• Sending the signal from one process
• Recieving the signal by another process. You can ignore, terminate, catch signal

Examples:

Number	Name	Default	Corresponding Event
1	SIGHUP	terminate	terminal line hangup

Sending SIgnals

From shell with command: $ /bin/kill -9 2423

From shell with keystroke to running process $ start-my-process

• CTRL + C sends SIGINT
• CTRL + Z sends SIGTSTP

There is also a C function and an Assembly syscall

Receiving Signals