You could store the message definitions in an (external) xml configuration file.
use strict;
use XML::Simple;
my $msg = LoadMsgConfig();
print "$msg->{0}\n"; # look up by id
print "$msg->{thanks}\n"; # look up by mnemonics
sub LoadMsgConfig
{
my $xs = new XML::Simple();
my $xmlmsg = do { local $/; <DATA> };
my $tags = $xs->XMLin($xmlmsg);
return undef if ! defined $tags->{msg};
my %msg;
foreach (keys %{$tags->{msg}})
{
$msg{$_} = $tags->{msg}{$_}{text};
$msg{$tags->{msg}{$_}{id}} = $msg{$_};
}
# undef $xmlmsg, $tags, $xs;
return \%msg;
}
__DATA__
<?xml version="1.0"?>
<config>
<msg id="0" name="wrong_input" text="Wrong input"/>
<msg id="1" name="thanks" text="Thanks for signing up with us"
+/>
<msg id="2" name="go_away" text="Go away hacker"/>
</config>
And the output -
Wrong input
Thanks for signing up with us