#!/usr/bin/env perl

use strict;
use warnings;

# Simulate Tie::File array
my @config_file = map { chomp; $_ } <DATA>;

print_config('Initial config');

for (@config_file) {
    $_ = /^\s*terminal\b/ ? change_value(terminal => $_)
       : /^\s*editor\b/   ? change_value(editor => $_)
       : /^\s*names\b/    ? get_tags($_)
       :                    $_;
}

print_config('Final config');

sub change_value {
    my ($key, $line) = @_;
    print "Current: $line\n";
    print 'Change (Enter to keep): ';
    chomp(my $new_value = <>);

    if ($new_value) {
        $line =~ s/^(\s*$key\s*=\s*")[^"]+("\s*)$/$1$new_value$2/;
    }

    return $line;
}

sub get_tags {
    my $line = shift;

    $line =~ /^\s*names\s*=\s*{\s*([^}]+)/;
    (my $names = $1) =~ y/" //d;
    my @tags = split /,/ => $names;
    print "TAGS: @tags\n";

    return $line;
}

sub print_config {
    my $heading = shift;
    print '=' x 64, "\n";
    print "$heading\n";
    print '-' x 64, "\n";
    print "$_\n" for @config_file;
    print '=' x 64, "\n";
    return;
}

__DATA__
-- This is used later as the default terminal and editor to run.
terminal = "urxvt"
editor = "vim"
-- Define a tag table which hold all screen tags.
tags = {
    names = { "Main", "WWW", "GIMP", "EMail", 6, 7 },