Library: GNU bash Command Reference (Darwin 9.0): trap

Library: GNU bash Command Reference (Darwin 9.0)

trap

trap: trap [-lp] [arg signal_spec ...]

The command ARG is to be read and executed when the shell receives
signal(s) SIGNAL_SPEC.  If ARG is absent (and a single SIGNAL_SPEC
is supplied) or `-', each specified signal is reset to its original
value.  If ARG is the null string each SIGNAL_SPEC is ignored by the
shell and by the commands it invokes.  If a SIGNAL_SPEC is EXIT (0)
the command ARG is executed on exit from the shell.  If a SIGNAL_SPEC
is DEBUG, ARG is executed after every simple command.  If the`-p' option
is supplied then the trap commands associated with each SIGNAL_SPEC are
displayed.  If no arguments are supplied or if only `-p' is given, trap
prints the list of commands associated with each signal.  Each SIGNAL_SPEC
is either a signal name in  or a signal number.  Signal names
are case insensitive and the SIG prefix is optional.  `trap -l' prints
a list of signal names and their corresponding numbers.  Note that a
signal can be sent to the shell with "kill -signal $$".

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