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Re: See if a certain package has a certain sub, without executing that sub

by gmax (Abbot)
on Mar 20, 2004 at 15:27 UTC ( #338300=note: print w/replies, xml ) Need Help??


in reply to See if a certain package has a certain sub, without executing that sub

Use the can method (it's a method of the UNIVERSAL package, so every class in Perl has access to it).

#!/usr/bin/perl use strict; use warnings; package Communications; sub SendMessage { my $packages = shift; my $msg = shift; for (@$packages) { if ($_->can('ReceiveMessage') ) { $_->ReceiveMessage($msg); } else { print "$_ can't ReceiveMessage\n" } } } sub ReceiveMessage { print __PACKAGE__, "::ReceiveMessage('$_[1]')\n"; } package Second; sub ReceiveMessage { print __PACKAGE__, "::ReceiveMessage('$_[1]')\n"; } package Other; sub nothing { print "\n"; } package main; my @packages = qw(Communications Other Second); Communications::SendMessage( \@packages, 'hello'); __END__ output: Communications::ReceiveMessage('hello') Other can't ReceiveMessage Second::ReceiveMessage('hello')
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Re: Re: See if a certain package has a certain sub, without executing that sub
by muba (Priest) on Mar 20, 2004 at 15:33 UTC
    Wow! This one is great! It's also nice to read:
    "if it can receive message" :)
    Thank you a lot!

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