I want to pass it by reference, and give it a meaningful identifier in the context of the subroutine. (ie not have to use $_[0] throughout the subroutine.) (Your second example)

-Andrew.

You can use a simple scalar reference, then.

sub alter_var { 
    my $scalar_ref = shift;
    $$scalar_ref =~ s/a/b/;
}

my $scalar = "foobarbaz";
alter_var( \$scalar );
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For more, see perlreftut.

Also note that esskar's second example, which works on $_[0] directly, will alter the scalar passed into the parameter list. (In this case, $_[0] is an alias, not a reference, so there is no need to dereference anything.)

I kind of wanted to use a local alias for $_[0], rather than have to use a reference that I have to remember to dereference everywhere.

I guess I just want to say:

    alias $var_in_sub = $_[0];
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Just to give $_[0] a meaningful name in the context of the subrountine, such that $var_in_sub and $_[0] are the same thing. In the same way as $var_elsewhere and $_[0] are the same thing when calling alter_var($var_elsewhere).

I guess this can't be done in Perl, without using references and dereferencing - which is fine. No big deal.

-Andrew.

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Andrew Tomazos  |  andrew@tomazos.com  |  www.tomazos.com