Re: $^S and eval

[Pete Jordan <pjordan1@email.mot.com>]

Tom Christiansen wrote:

> Due to an implementation glitch, the C<$SIG{__DIE__}> hook is called
> even inside an eval().  Do not use this to rewrite a pending exception
> in C<$@>, or as a bizarre substitute for overriding CORE::GLOBAL::die().
> This strange action at a distance may be fixed in a future release
> so that C<$SIG{__DIE__}> is only called if your program is about
> to exit, as was the original intent.  Any other use is deprecated.

Fair enough. What, then, would be the most legitimate way of
(effectively) subclassing C<die> for a script? I ask as I use an
exception module here (in a mixture of straight Perl, Perl CGI and
mod_perl scripts) that currently contains a C<$SIG{__DIE__}> handler
that encapsulates the error text and re-dies. The code does a fair bit
of extra processing (munging text, optional stack traces etc.) but it
boils down to:

	INIT {
	  my $oldHandler=$SIG{__DIE__} || 'DEFAULT';

	  $SIG{__DIE__}=sub {
	    my $err=ref $_[0] ? shift : bless {TEXT=>join '', @_};

	    if (!defined $^S || $^S) {
	      local $SIG{__DIE__}=$oldHandler;
	      die $err;
            } else {
              $err->croak;
            }
	  };
	}

thus allowing me to do C<eval {die 'aargh'}; $@ and $@->croak> without
having to worry if $@ is an exception object or not.

Pete
-- 
use Disclaimer::Standard;	# Motorola GSM Software Factory
my $phone='+44 1793 564450';	# "'Not twisted,' Salzy once said of
my $fax='+44 1793 566918';	#  her own passion, 'it is helical.
my $mobile='+44 7973 725120';	#  That sounds better.'"

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References to:

Tom Christiansen <tchrist@chthon.perl.com>

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