Hello mike6535,

In the end I'd like to have several alternative "keys" per row, including some subset of abbreviations.

The behaviour you described is exactly what GetOpt::Long does with arguments. Take a loong breath and dive in it's source code to see how a real world wheel works.

Yes! you can reinvent the wheel (but see my signature..). In this case you can profit of the core module Text::Abbrev to have all unique abbreviations from a list, but you need to check for duplicates and collisions...

Probably have a dedicated sub to get the job done. Let's assume we want that the keys are in different languages and that values are just strings of words like in your example; something like (semitested!):

use strict;
use warnings;

my %multikeys;
my %yet_used;
             # alternatives                # value
multikeyize ('colors|colores|farben|col|c',"red green purple");
multikeyize ('animals|animalia|a',"sheep cow dog");

# warning example: redefining a masterkey
# multikeyize ('colors|xss|x',"tizio caio sempronio");

# warning example: redefining an alias
# multikeyize ('c|xss|x',"tizio caio sempronio");

sub multikeyize{
    my $alternatives= shift;
    my $value = shift;
    my @alternate = split /\|/,$alternatives;
    my $masterkey = shift @alternate;
    # masterkeys take the precedence..
    if ($yet_used{$masterkey}){
        print "\tWARNING '$masterkey' already defined! wiping previous
+ value!",
             (  $yet_used{$masterkey}=~/^1$/ ?
                "(was an alias)" :
                "(was a masterkey with value of '$yet_used{$masterkey}
+')"
              ),"\n";
        undef $yet_used{$masterkey};
    }
    $multikeys{$masterkey} = $yet_used{$masterkey} = $value;

    map { $yet_used{$_}++;
          $multikeys{$_} = \$multikeys{$masterkey};
          # just to show it..
          print "$_->";
    }
    grep {not exists $yet_used{$_} } @alternate;
    # just to show it..
    print "(masterkey) $masterkey = '$multikeys{$masterkey}'\n\n";
}


__OUTPUT__

colores->farben->col->c->(masterkey) colors = 'red green purple'

animalia->a->(masterkey) animals = 'sheep cow dog'
[download]

HtH
L*