in reply to a reference by any other name...

This may be what you want:

use strict;
use warnings;

my @array1;
my @array2;
my $ref1 = \@array1;
my $ref2 = \@array1;
my $ref3 = \@array2;

print "Maybe what you want\n" if $ref1 == $ref2;
print "Not what you want\n" if $ref1 == $ref3;

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Prints:

Maybe what you want

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Note that \@name1 returns a reference and I suspect what you want to know is if two references refer to the same object.

DWIM is Perl's answer to Gödel

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Re^2: a reference by any other name...
by blogical (Pilgrim) on Feb 20, 2006 at 01:55 UTC
    Right- I want multiple names for the same data, and each would logically produce an identical reference using \. Otherwise I could just my $ref2 = $ref1; But I don't want to use de-referencing notation when I address the data, so I don't want to just use a copy of the reference. I especially don't want a copy of the data: my @array2 = @array1;
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      I think there is a confusion of nomenclature here. \ returns a reference to something and that reference can be assigned to a scalar variable, which is then said to be a reference to the original something.

      A copy of the reference by using my $ref2 = $ref1; generates the same result as my $ref2 = \$something;. You seem to be talking about some sort of alias, somewhat like a *nix file system hard link. I am having trouble imagining a situation where you would require such a thing in Perl. Perhaps you need to show us a code snippet to illustrate the problem you are having?

      DWIM is Perl's answer to Gödel
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        The situation is thus:
        I'd like to use hashed and arrayed data, being passed into a function as references, using non-de-referencing notation.
        Instead of $array_ref->[0], I want to assign the data referenced by $array_ref to something like @array_by_another_name, so that I can then just say $array_by_another_name[0].
        If I just assign the de-referenced data to a like variable I will get a copy... (ie my @array2 = @{$array_ref}; is not what I want).
        my %foo = ('a' => 1);
my_sub(\%foo);

sub my_sub {
 my $foo_ref = shift;

 #Now I want to do something here to name %bar as pointing to %foo:
 #my %bar ????? $foo_ref;

 #such that 
 print $bar{a};
 #prints '1'

 #and if I were to
 $bar{b} = 2;
};

print $foo{b};
#prints '2'

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        I think I have a good grasp on wrangling references... but I'm always up for elucidation. This would indeed be like a hard reference on a unix system- it increases the reference count, but is otherwise treated like it IS what it refers to- no de-referencing needed.
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