Add translation-diff util script

.gitignore

@@ -13,3 +13,4 @@ run/
 *.iws
 .idea/
 out/
+translation-diff.diff

translation-diff.pl

@@ -0,0 +1,42 @@
+use constant {
+    BASE_LANG => "en_US",
+    OUTPUT_FILE => "translation-diff.diff"
+};
+
+my $lang = $ARGV[0] or die("Missing language to diff with");
+
+sub lang_file {
+    my ($lang) = @_;
+    my $filename = "src/main/resources/assets/refinedstorage/lang/" . $lang . ".lang";
+    open(my $fh, $filename) or die("Couldn't open $filename");
+    return $fh;
+}
+
+sub write_keys {
+    my ($lang, $lang_keys) = @_;
+    my $filename = $lang . ".tmp";
+    open(my $fh, '>', $filename) or die("Couldn't open temp file $filename for $lang for writing");
+    print $fh $lang_keys;
+    close $fh;
+    return $filename;
+}
+
+sub lang_keys {
+    my ($lang_file) = @_;
+    my $keys = "";
+    while (my $line = <$lang_file>) {
+        my @p = split("=", $line);
+        $keys .= $p[0] . "\n";
+    }
+    return $keys;
+}
+
+my $base_keys = lang_keys(lang_file(BASE_LANG));
+my $t1 = write_keys(BASE_LANG, $base_keys);
+
+my $lang_keys = lang_keys(lang_file($lang));
+my $t2 = write_keys($lang, $lang_keys);
+
+system("diff -s -y $t1 $t2 > " . OUTPUT_FILE);
+
+unlink($t1, $t2);