Qt Linguist Manual: Release Manager

lupdate

Usage: lupdate myproject.pro

This is a simple command line tool. lupdate reads a Qt .pro project file, finds the translatable strings in the specified source, header and Qt Designer interface files, and produces or updates the .ts translation files listed in the project file. The translation files are given to the translator who uses Qt Linguist to read the files and insert the translations.

Companies that have their own translators in-house may find it useful to run lupdate regularly, perhaps monthly, as the application develops. This will lead to a fairly low volume of translation work spread evenly over the life of the project and will allow the translators to support a number of projects simultaneously.

Companies that hire in translators as required may prefer to run lupdate only a few times in the application's life cycle, the first time might be just before the first test phase. This will provide the translator with a substantial single block of work and any bugs that the translator detects may easily be included with those found during the initial test phase. The second and any subsequent lupdate runs would probably take place during the final beta phase.

The .ts file format is a simple human-readable XML format that can be used with version control systems if required.

Qt Linguist is also able to import and export XML Localization Interchange File Format (XLIFF) files, making it possible to take advantage of tools and translation services that work with this format.

Pass the -help option to lupdate to obtain the list of supported options:

 Usage:
     lupdate [options] [project-file]
     lupdate [options] [source-file|path]... -ts ts-files
 Options:
     -help  Display this information and exit.
     -noobsolete
            Drop all obsolete strings.
     -extensions <ext>[,<ext>]...
            Process files with the given extensions only.
            The extension list must be separated with commas, not with whitespace.
            Default: 'ui,c,c++,cc,cpp,cxx,ch,h,h++,hh,hpp,hxx'.
     -silent
            Don't explain what is being done.
     -version
            Display the version of lupdate and exit.

     Usage:
         lrelease [options] project-file
         lrelease [options] ts-files [-qm qm-file]
     Options:
         -help  Display this information and exit
         -compress
                Compress the .qm files
         -nounfinished
                Do not include unfinished translations
         -silent
                Don't explain what is being done
         -version
                Display the version of lrelease and exit