"""
No no no. Don't use kill -9.
It doesn't give the process a chance to cleanly:
1) shut down socket connections
2) clean up temp files
3) inform its children that it is going away
4) reset its terminal characteristics
and so on and so on and so on.

Generally, send 15, and wait a second or two, and if that doesn't
work, send 2, and if that doesn't work, send 1. If that doesn't,
REMOVE THE BINARY because the program is badly behaved!

Don't use kill -9. Don't bring out the combine harvester just to tidy
up the flower pot.
"""
rappel sur les signaux: http://www.tutorialspoint.com/unix/unix-signals-traps.htm
"""
SIGHUP 1 Hang up detected on controlling terminal or death of controlling process
SIGINT 2 Issued if the user sends an interrupt signal (Ctrl + C).
SIGQUIT 3 Issued if the user sends a quit signal (Ctrl + D).
SIGFPE 8 Issued if an illegal mathematical operation is attempted
SIGKILL 9 If a process gets this signal it must quit immediately and will not perform any clean-up operations
SIGALRM 14 Alarm Clock signal (used for timers)
SIGTERM 15 Software termination signal (sent by kill by default).
"""