msggrep

msggrep [OPTION]... PATTERN [FILE]...

-e PATTERN or --regexp=PATTERN
    Specifies the regular expression PATTERN to search for. Can be used multiple times to specify multiple patterns.

-f FILE or --file=FILE
    Reads patterns from FILE, one per line, and treats each line as a separate pattern.

-i or --ignore-case
    Ignores case distinctions when matching PATTERN.

-v or --invert-match
    Selects messages that do not match the specified PATTERN.

--msgid
    Searches exclusively within the 'msgid' (original message ID) field of PO entries.

--msgstr
    Searches exclusively within the 'msgstr' (translated string) field of PO entries.

--msgctxt
    Searches exclusively within the 'msgctxt' (message context) field of PO entries.

--location
    Searches within the source code location comments (e.g., '#: src/file.c:123') associated with each message.

--comment
    Searches within translator comments (e.g., '#. comment') of PO entries.

--files-with-matches
    Prints only the names of files that contain at least one matching message, one per line.

--add-location
    Adds file and line number comments to the output for each matching entry, useful for debugging.

msggrep is a specialized command-line utility within the GNU Gettext toolset, designed for searching for strings within Portable Object (PO) files. Unlike the general-purpose grep command, msggrep understands the structured format of PO files, allowing it to search specific fields such as message IDs (msgid), translated strings (msgstr), context (msgctxt), source code locations, or translator comments.

This makes it an invaluable tool for translators, developers, and localization engineers to quickly find, review, and manage translatable content, identify untranslated messages, or locate specific phrases across multiple language files. Its output typically presents the matching entries in a readable PO file format.

msggrep is specifically designed for Gettext PO files and will not function correctly on arbitrary text files. Its reliance on the PO file structure means it requires valid input files to operate efficiently. Performance can degrade with extremely large PO files or when searching across thousands of files without specific file exclusions.

msggrep exits with a status of 0 if one or more matches are found, 1 if no matches are found, and a value greater than 1 if an error occurs. This behavior is consistent with grep and useful for scripting.

msggrep supports GNU grep's regular expression syntax, allowing for powerful pattern matching. This includes both Basic Regular Expressions (BRE) and Extended Regular Expressions (ERE) by default, providing flexibility for complex searches.

msggrep is an integral part of the GNU Gettext project, which was initiated by the Free Software Foundation in the early 1990s to provide a robust framework for internationalization and localization. Its development arose from the need to manage and inspect the content of PO translation files efficiently, mirroring the functionality of grep but tailored for the specific structure of Gettext message catalogs. It has evolved alongside the Gettext system to support new features and improve performance in managing large translation projects.

grep(1), gettext(1), msgmerge(1), xgettext(1), msgfmt(1)