Have a look at `man bash` and search for 'trap.'
trap [-lp] [[arg] sigspec ...]
The command arg is to be read and executed when the
shell receives signal(s) sigspec. If arg is absent
(and there is a single sigspec) or -, each specified
signal is reset to its original disposition (the
value it had upon entrance to the shell). If arg is the
null string the signal specified by each
sigspec is ignored by the shell and by the commands it
invokes. If arg is not present and -p has been
supplied, then the trap commands associated with each
sigspec are displayed. If no arguments are sup-
plied or if only -p is given, trap prints the list
of commands associated with each signal. The -l
option causes the shell to print a list of signal names
and their corresponding numbers. Each sigspec
is either a signal name defined in <signal.h>, or a
signal number. Signal names are case insensitive
and the SIG prefix is optional. [...]