Using xgettext to Extract Gettext Strings (with examples)

1: Scan file and output strings to messages.po

xgettext path/to/input_file

Motivation:

This command is useful when you want to extract gettext strings from a single code file and store them in a .po file. This allows you to easily manage and translate these strings using gettext tools.

Explanation:

• path/to/input_file: Specifies the path to the input file containing the code you want to scan for gettext strings.

Example Output:

The command will parse the code in the input file and extract all the gettext strings found. It will then generate a .po file named messages.po in the current directory. The .po file will contain the extracted strings along with placeholders and other metadata needed for translation.

2: Use a different output filename

xgettext --output path/to/output_file path/to/input_file

Motivation:

In some cases, you may want to specify a custom output file name instead of the default messages.po. This can be useful when you want to organize your translations or integrate them into an existing translation workflow.

Explanation:

• --output path/to/output_file: Specifies the path and filename of the output .po file.

Example Output:

The command will scan the input file for gettext strings and generate a .po file with the specified name and location. For example, xgettext --output translations/myapp.po path/to/input_file will create a myapp.po file in the translations directory.

3: Append new strings to an existing file

xgettext --join-existing --output path/to/output_file path/to/input_file

Motivation:

When you have an existing .po file with some translated strings and you want to add new gettext strings without losing the existing translations, you can use this command. Instead of creating a new file from scratch, it will append the new strings to the existing file.

Explanation:

• --join-existing: Specifies that the new strings should be joined with the existing translations.
• --output path/to/output_file: Specifies the path and filename of the output .po file.

Example Output:

The command will scan the input file for gettext strings and add any new strings to the existing .po file specified in the output path. The output file will contain both the existing translations and the newly extracted strings.

4: Don’t add a header containing metadata to the output file

xgettext --omit-header path/to/input_file

Motivation:

The default behavior of xgettext is to add a header to the output .po file containing metadata like the project name, copyright, and creation date. However, in some cases, you may want to omit this header, for example, when integrating with an existing translation management system that handles these metadata separately.

Explanation:

• --omit-header: Instructs xgettext to exclude the header from the output file.

Example Output:

The command will extract the gettext strings from the input file and generate a .po file without the usual header containing metadata. This can make the resulting file more compatible with certain translation tools or workflows.