msgfmt

Compile a file to messages.mo

$ msgfmt [file.po]

$ msgfmt [path/to/file.po] [[-o|--output-file]] [path/to/file.mo]

$ msgfmt [[-h|--help]]

msgfmt [OPTION]... [FILE]...
msgfmt -o OUTPUT_FILE [OPTION]... [FILE]...

-o, --output-file=FILE
    Specify the name of the output MO file. If not specified, output goes to standard output.

-c, --check-format
    Perform format string checks. Ensures printf-like format strings match between original and translated messages.

-C, --check-header
    Check the PO file header entry for common errors or missing information.

-v, --verbose
    Print more detailed information about the compilation process, including progress and statistics.

--statistics
    Print statistics about the processed PO file, such as the number of translated, untranslated, and fuzzy entries.

-D, --directory=DIRECTORY
    Add DIRECTORY to the list of directories where input files are searched for.

-l, --locale=LOCALE
    Specify the locale name. Useful for validating plural forms specific to a locale.

-f, --force-po
    Force output of the MO file even if some fatal errors are encountered during compilation.

--strict
    Enable stricter checks, which might report more warnings or errors.

--version
    Display version information and exit.

--help
    Display a help message and exit.

msgfmt is a crucial command-line utility within the GNU Gettext framework, which is the standard system for internationalization and localization on Unix-like operating systems. Its primary function is to compile human-readable PO (Portable Object) files into compact, machine-optimized MO (Machine Object) binary files.

Translators typically work with PO files, which contain original strings (msgid) and their corresponding translations (msgstr). Before an application can use these translations, they must be converted into the MO format, which is efficient for runtime lookups by the Gettext library.

msgfmt performs this compilation, checking for syntax errors, format string mismatches, and other potential issues within the PO files. It ensures that the generated MO file is valid and ready for use by software applications, enabling them to display messages in the user's preferred language.

Incorrect syntax or malformed entries in PO files can lead to compilation failures unless `--force-po` is used.
Plural forms are locale-specific; incorrect plural equations or missing plural translations in the PO file for a given locale can cause runtime issues or incorrect display.
Ensure the output directory has appropriate write permissions for msgfmt to create the MO file.

To compile a single PO file named en_US.po into an MO file named en_US.mo:
msgfmt -o en_US.mo en_US.po

To compile multiple PO files into one MO file with statistics:
msgfmt --statistics -o translations.mo file1.po file2.po

msgfmt provides detailed error messages and warnings to help translators and developers identify issues in PO files. Common errors include unmatched format specifiers (e.g., %s in msgid but not in msgstr), syntax errors, or missing header information. By default, fatal errors will prevent the MO file from being generated, ensuring only valid translations are deployed.

msgfmt is an integral part of the GNU Gettext internationalization framework, which was first released in 1995. Developed primarily by Ulrich Drepper, it quickly became the de-facto standard for software internationalization on Linux and other Unix-like systems. msgfmt's role has remained consistent: to efficiently convert human-readable translations into a format usable by applications. Its development has mirrored the evolution of the Gettext project itself, with ongoing improvements to error checking, performance, and support for various localization complexities, such as plural forms and message contexts.

gettext(1), xgettext(1), msginit(1), msgmerge(1), msgunfmt(1)