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.

---

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

Wouldn't this be considered to be semi-alias? Well you create one more variables but still does not have the "contents" as it is still a pointer/reference. So memory is OK here?

sub alter_var {
    my $aliasvar = $_[0];    # Nice to have C like proto types but...
    ${$aliasvar} =~ s/a/b/g;
#   ${$_[0]} =~ s/a/b/g;   # This uses $_[0] and works
}
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I guess this can't be done in Perl, without using references and dereferencing - which is fine. No big deal.

Someone always has to dereference. I'm not sure, but I think you're after one of the alias modules (Lexical::Alias, Tie::Alias, Variable::Alias, Data::Alias).

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