scummvm/po/msgcut

#!/usr/bin/env perl

use strict;
use warnings;
use Tie::IxHash;
use open qw(:std :utf8);

sub readPOT {
	my ($fn) = @_;
	open my $fh, "<", $fn or die "Could not open $fn: $!";
	local $/ = "";

	my %ids;
	tie %ids, 'Tie::IxHash';
	my $ret = { ids => \%ids, header => scalar <$fh> };

	while (defined (my $block = <$fh>)) {
		my ($context) = $block =~ /msgctxt "(.+)"/ || "(none)";
		my ($msgid) = $block =~ /msgid "(.*)"/;
		if (! length $msgid) {
			($msgid) = $block =~ /msgid ""(.*?)^msgstr/sm;
			$msgid =~ s/"\n"//;
		}
		$ids{"$context/$msgid"} = $block;
	}

	return $ret;
}

my ($derivedfn, $mainfn) = @ARGV;

my $main = readPOT $mainfn;
my $derived = readPOT $derivedfn;

open my $out, ">", $derivedfn or die "Cannot open $derivedfn for writing: $!";
print $out $derived->{header};
for my $key (keys %{$derived->{ids}}) {
	print $out $derived->{ids}{$key} unless exists $main->{ids}{$key};
}