sigtrap - Perl pragma to enable simple signal handling
use sigtrap; use sigtrap qw(stack-trace old-interface-signals); # equivalent use sigtrap qw(BUS SEGV PIPE ABRT); use sigtrap qw(die INT QUIT); use sigtrap qw(die normal-signals); use sigtrap qw(die untrapped normal-signals); use sigtrap qw(die untrapped normal-signals stack-trace any error-signals); use sigtrap 'handler' => \&my_handler, 'normal-signals'; use sigtrap qw(handler my_handler normal-signals stack-trace error-signals);
The sigtrap pragma is a simple interface to installing signal handlers. You can have it install one of two handlers supplied by sigtrap itself (one which provides a Perl stack trace and one which simply die()s), or alternately you can supply your own handler for it to install. It can be told only to install a handler for signals which are either untrapped or ignored. It has a couple of lists of signals to trap, plus you can supply your own list of signals.
The arguments passed to the use statement which invokes sigtrap are processed in order. When a signal name or the name of one of sigtrap's signal lists is encountered a handler is immediately installed, when an option is encountered it affects subsequently installed handlers.
These options affect which handler will be used for subsequently installed signals.
%SIG
.
sigtrap has a few built-in lists of signals to trap. They are:
For each of these three lists, the collection of signals set to be trapped is checked before trapping; if your architecture does not implement a particular signal, it will not be trapped but rather silently ignored.
/^[A-Z][A-Z0-9]*$/
) indicates that sigtrap should install a handler for that name.
Provide a stack trace for the old-interface-signals:
use sigtrap;
Ditto:
use sigtrap qw(stack-trace old-interface-signals);
Provide a stack trace on the 4 listed signals only:
use sigtrap qw(BUS SEGV PIPE ABRT);
Die on INT or QUIT:
use sigtrap qw(die INT QUIT);
Die on HUP, INT, PIPE or TERM:
use sigtrap qw(die normal-signals);
Die on HUP, INT, PIPE or TERM, except don't change the behavior for signals which are already trapped or ignored:
use sigtrap qw(die untrapped normal-signals);
Die on receipt one of an of the normal-signals which is currently untrapped, provide a stack trace on receipt of any of the error-signals:
use sigtrap qw(die untrapped normal-signals stack-trace any error-signals);
Install
my_handler()
as the
handler for the normal-signals:
use sigtrap 'handler', \&my_handler, 'normal-signals';
Install
my_handler()
as the
handler for the normal-signals, provide a Perl stack trace on receipt of
one of the error-signals:
use sigtrap qw(handler my_handler normal-signals stack-trace error-signals);
If rather than formatting bugs, you encounter substantive content errors in these documents, such as mistakes in the explanations or code, please use the perlbug utility included with the Perl distribution.