#!/usr/bin/env perl

my ($vowel) = @ARGV;

my @codes = (
    [38 => ['a', 'A']],
    [26 => ['e', 'E']],
    [31 => ['i', 'I']],
    [32 => ['o', 'O']],
    [30 => ['u', 'U']],
);

if ($vowel) {
    foreach (@codes) {
        $_->[1][0] = lc $vowel;
        $_->[1][1] = uc $vowel;
    }
}

system('xmodmap', map(keycode(@$_), @codes));

sub keycode {
    my ($code, $pair) = @_;
    return ('-e', "keycode $code = @$pair");
}