Re: How do I test the validity of a CODE reference?

You don't need eval and you can just inspect the main namespace for whether a subroutine of that name is defined:

use strict;
use Data::Dumper;
sub foo {
    print "foo\n";
}

for my $subname (@ARGV) {
    my $glob = $::{$subname};

    warn defined $glob ? "'*$subname' exists"
                       : "'*$subname' not found";
    if ($glob) {
        my $sub = *{$glob}{CODE};

        warn defined $sub ? "'$subname' exists"
                          : "'$subname' not found";


        &$sub if $sub
    };
}
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Re^2: How do I test the validity of a CODE reference? by tinita (Parson) on Aug 10, 2008 at 12:57 UTC
couldn't you just do `if ( my $sub = main->can($subname) ) { $sub->(...) }` [download] ?	[reply] [d/l]
Re^3: How do I test the validity of a CODE reference? by ikegami (Patriarch) on Aug 10, 2008 at 13:27 UTC
Not quite. `can` is meant for methods, so it obeys inheritance.	[reply] [d/l]
Re^2: How do I test the validity of a CODE reference? by pilap (Initiate) on Aug 08, 2008 at 17:33 UTC
The reason I decided to use `eval` is that the user can put the `require`d code in a package, and I don't need to know anything about it as long as he uses the fully qualified name as the subroutine name. Out of curiosity, how would you examine the symbol table for a package whose name you get from a variable? I'm not very comfortable with the syntax for typeglobs and Perl symbol tables...	[reply] [d/l] [select]
Re^3: How do I test the validity of a CODE reference? by Corion (Patriarch) on Aug 09, 2008 at 08:45 UTC
You can inspect any package, as the symbols for `My::Package` live in the `%My::Package::` hash. The easiest way to get at those hashes is via soft references: `use strict; use Data::Dumper; my $package = 'Data::Dumper'; # just as an example { no strict 'refs'; # we're using strings as symbols. Nasty, but con +venient warn Dumper \%{ "$package\::" }; };` [download]	[reply] [d/l] [select]