kill - send a signal to a process
kill [-n] process
Signal number to send
Named signal to send
# Send signal 15 to process 35
kill -9 40
# Send signal 9 to process 40
kill -2 0
# Send signal 2 to whole terminal process group
kill -HUP -123
# Send a hangup to process group 123
A signal is sent to a given process.
By default signal 15 (SIGTERM) is sent.
Process 0 means all the processes in the sender's process group.
A process group can be signalled by the negative value of the process
Signals may be numerical, or the name of the signal without SIG.