Programming Perl, 4th Edition

Signal Handlers

These options affect which handler will be used for signals installed later:

stack–trace

This pragma-supplied handler outputs a Perl stack trace to STDERR and then tries to dump core. This is the default signal handler.

die

This pragma-supplied handler calls die via Carp::croak with a message indicating the signal caught.

handler YOURHANDLER

YOURHANDLER will be used as the handler for signals installed later. YOURHANDLER can be any value valid for assignment into %SIG. Remember that the proper functioning of many C library calls (particularly standard I/O calls) cannot be guaranteed within a signal handler. Worse, it’s hard to guess which bits of C library code are called from which bits of Perl code. (On the other hand, many signals that sigtrap traps are pretty vile—they’re gonna take you down anyway, so there’s not much harm in trying to do something, now is there?)