#!/usr/bin/perl

use Data::Dumper;
simple_call( uniq1 => 1, uniq2 => 2, dup1 => 3, dup1 => 4 );
sub simple_call { 
    my %hash = ();
    for ( my ($key, $value); $key = shift; ) {
        $value = shift;
        if ( dupAllow( $key ) ) {
            unless ( $hash{ $key } ) {
                my @tmp = ();
                $hash{ $key } = \@tmp;
            }
            my $aref = $hash{ $key };
            push @$aref, $value;
        }
        else {
            $hash{ $key } = $value;
        }
    }

    print Dumper( \%hash );
    # continue subroutine processing
    
}

sub dupAllow {
    my $key = shift;
    ( $key eq 'dup1' ) and return 1;
    ( $key eq 'dup2' ) and return 1;
    return 0;
}