phpman > man > sigtrap(3pm)

NAME
    sigtrap - Perl pragma to enable simple signal handling

SYNOPSIS
        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);

DESCRIPTION
    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.

OPTIONS
  SIGNAL HANDLERS
    These options affect which handler will be used for subsequently installed signals.

    stack-trace
        The handler used for subsequently installed signals outputs a Perl stack trace to STDERR and
        then tries to dump core. This is the default signal handler.

    die The handler used for subsequently installed signals calls "die" (actually "croak") with a
        message indicating which signal was caught.

    handler *your-handler*
        *your-handler* will be used as the handler for subsequently installed signals.
        *your-handler* can be any value which is valid as an assignment to an element of %SIG. See
        perlvar for examples of handler functions.

  SIGNAL LISTS
    sigtrap has a few built-in lists of signals to trap. They are:

    normal-signals
        These are the signals which a program might normally expect to encounter and which by
        default cause it to terminate. They are HUP, INT, PIPE and TERM.

    error-signals
        These signals usually indicate a serious problem with the Perl interpreter or with your
        script. They are ABRT, BUS, EMT, FPE, ILL, QUIT, SEGV, SYS and TRAP.

    old-interface-signals
        These are the signals which were trapped by default by the old sigtrap interface, they are
        ABRT, BUS, EMT, FPE, ILL, PIPE, QUIT, SEGV, SYS, TERM, and TRAP. If no signals or signals
        lists are passed to sigtrap, this list is used.

    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.

  OTHER
    untrapped
        This token tells sigtrap to install handlers only for subsequently listed signals which
        aren't already trapped or ignored.

    any This token tells sigtrap to install handlers for all subsequently listed signals. This is
        the default behavior.

    *signal*
        Any argument which looks like a signal name (that is, "/^[A-Z][A-Z0-9]*$/") indicates that
        sigtrap should install a handler for that name.

    *number*
        Require that at least version *number* of sigtrap is being used.

EXAMPLES
    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);