Re: Re: test for subroutine existence

[twerq]

Sorry, I probably wasn't clear enough in my original post (but that's why I added the code)...
I need to be able to test for a subroutine's existence, a subroutine who'se name is only available to me in a scalar -- so I can't very well use defined &my_sub (or can I?)

fuzzyping's right, eval does work pretty well, except that I end up actually executing the subroutine itself just to see if it's there -- I'd prefer not to actually run it at test time...

--twerq

[Abigail-II]

No eval needed.

#!/usr/bin/perl

use warnings 'all';
use strict;

sub my_sub {1}

foreach my $sub (qw /my_sub no_sub/) {
    print "$sub ", defined &$sub ? "exists\n" : "doesn't exist\n";
}

__END__
my_sub exists
no_sub doesn't exist

Abigail

[twerq]

Okay, anyway -- now it seems pretty obvious:


print "my_sub ", test_for_sub("my_sub") ? "exists\n" : "doesn't exist\
+n";
print "no_sub ", test_for_sub("no_sub") ? "exists\n" : "doesn't exist\
+n";

sub test_for_sub {
        my ($expr) = @_;
        return eval "defined &$expr";
}

sub my_sub { 1; }



--twerq