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Log::Report::Lexicon::Index(3pm) User Contributed Perl Documentation Log::Report::Lexicon::Index(3pm)


Log::Report::Lexicon::Index - search through available translation files


 my $index = Log::Report::Lexicon::Index->new($directory);
 my $fn    = $index->find('my-domain', 'nl_NL.utf-8');


This module handles the lookup of translation files for a whole directory tree. It is lazy loading, which means that it will only build the search tree when addressed, not when the object is created.



Create an index for a certain directory. If the directory does not exist or is empty, then the object will still be created.

All files the $directory tree which are recognized as an translation table format which is understood will be listed. Momentarily, those are:

. files with extension "po", see Log::Report::Lexicon::POTcompact
. [0.993] files with extension "mo", see Log::Report::Lexicon::MOTcompact

[0.99] Files which are in directories which start with a dot (hidden directories) and files which start with a dot (hidden files) are skipped.


Returns the directory name.
$obj->addFile( $basename, [$absolute] )
Add a certain file to the index. This method returns the $absolute path to that file, which must be used to access it. When not explicitly specified, the $absolute path will be calculated.
$obj->find($textdomain, $locale)
Lookup the best translation table, according to the rules described in chapter "DETAILS", below.

Returned is a filename, or "undef" if nothing is defined for the $locale (there is no default on this level).

For internal use only. Force the creation of the index (if not already done). Returns a hash with key-value pairs, where the key is the lower-cased version of the filename, and the value the case-sensitive version of the filename.
$obj->list( $domain, [$extension] )
Returned is a list of filenames which is used to update the list of MSGIDs when source files have changed. All translation files which belong to a certain $domain are listed.

The $extension filter can be used to reduce the filenames further, for instance to select only "po", "mo" or "gmo" files, and ignore readme's. Use an string, without dot and interpreted case-insensitive, or a regular expression.


  my @l = $index->list('my-domain');
  my @l = $index->list('my-domain', 'po');
  my @l = $index->list('my-domain', qr/^readme/i);


It's always complicated to find the lexicon files, because the perl package can be installed on any weird operating system. Therefore, you may need to specify the lexicon directory or alternative directories explicitly. However, you may also choose to install the lexicon files in between the perl modules.

merge lexicon files with perl modules

By default, the filename which contains the package which contains the textdomain's translator configuration is taken (that can be only one) and changed into a directory name. The path is then extended with "messages" to form the root of the lexicon: the top of the index. After this, the locale indication, the lc-category (usually LC_MESSAGES), and the "textdomain" followed by ".po" are added. This is exactly as gettext(1) does, but then using the PO text file instead of the MO binary file.

. Example: lexicon in module tree

My module is named "Some::Module" and installed in some of perl's directories, say "~perl5.8.8". The module is defining textdomain "my-domain". The translation is made into "nl-NL.utf-8" (locale for Dutch spoken in The Netherlands, utf-8 encoded text file).

The default location for the translation table is under

for instance

There are alternatives, as described in Log::Report::Lexicon::Index, for instance

The exact gettext defined format of the locale is
language[_territory[.codeset]][@modifier] The modifier will be used in above directory search, but only if provided explicitly.

The manual "info gettext" determines the rules. During the search, components of the locale get stripped, in the following order:

1. codeset
2. normalized codeset
3. territory
4. modifier

The normalized codeset (character-set name) is derived by

1. Remove all characters beside numbers and letters.
2. Fold letters to lowercase.
3. If the same only contains digits prepend the string "iso".

To speed-up the search for the right table, the full directory tree will be indexed only once when needed the first time. The content of all defined lexicon directories will get merged into one tree.


My module is named "Some::Module" and installed in some of perl's directories, say "~perl5". The module is defining textdomain "my-domain". The translation is made into "nl-NL.utf-8" (locale for Dutch spoken in The Netherlands, utf-8 encoded text file).

The translation table is taken from the first existing of these files:

Then, attempts are made which are not compatible with gettext. The advantage is that the directory structure is much simpler. The idea is that each domain has its own locale installation directory, instead of everything merged in one place, what gettext presumes.

In order of attempts:

Filenames may get mutulated by the platform (which we will try to hide from you [please help improve this]), and are treated case-INsensitive!


This module is part of Log-Report-Lexicon distribution version 1.11, built on March 22, 2018. Website:


Copyrights 2007-2018 by [Mark Overmeer <>]. For other contributors see ChangeLog.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See

2018-04-16 perl v5.26.1