4. Making the PO Template File

After preparing the sources, the programmer creates a PO template file. This section explains how to use xgettext for this purpose.

4.1 Invoking the xgettext Program

4.1 Invoking the xgettext Program

xgettext [option] [inputfile] ...

The xgettext program extracts translatable strings from given input files.

4.1.1 Input file location

`inputfile ...'

Input files.

`-f file'

`--files-from=file'

Read the names of the input files from file instead of getting them from the command line.

`-D directory'

`--directory=directory'

Add directory to the list of directories. Source files are searched relative to this list of directories. The resulting `.po' file will be written relative to the current directory, though.

If inputfile is `-', standard input is read.

4.1.2 Output file location

`-d name'

`--default-domain=name'

Use `name.po' for output (instead of `messages.po').

`-o file'

`--output=file'

Write output to specified file (instead of `name.po' or `messages.po').

`-p dir'

`--output-dir=dir'

Output files will be placed in directory dir.

If the output file is `-' or `/dev/stdout', the output is written to standard output.

4.1.3 Choice of input file language

`-L name'

`--language=name'

Specifies the language of the input files. The supported languages are C, C++, ObjectiveC, PO, Python, Lisp, EmacsLisp, librep, Java, awk, YCP, Tcl, RST, Glade.

`-C'

`--c++'

This is a shorthand for --language=C++.

By default the language is guessed depending on the input file name extension.

4.1.4 Operation mode

`-j'

`--join-existing'

Join messages with existing file.

`-x file'

`--exclude-file=file'

Entries from file are not extracted. file should be a PO or POT file.

`-c [tag]'

`--add-comments[=tag]'

Place comment block with tag (or those preceding keyword lines) in output file.

4.1.5 Language=C/C++ specific options

`-a'

`--extract-all'

Extract all strings.

`-k keywordspec'

`--keyword[=keywordspec]'

Additional keyword to be looked for (without keywordspec means not to use default keywords).

If keywordspec is a C identifer id, xgettext looks for strings in the first argument of each call to the function or macro id. If keywordspec is of the form `id:argnum', xgettext looks for strings in the argnumth argument of the call. If keywordspec is of the form `id:argnum1,argnum2', xgettext looks for strings in the argnum1st argument and in the argnum2nd argument of the call, and treats them as singular/plural variants for a message with plural handling.

The default keyword specifications, which are always looked for if not explicitly disabled, are gettext, dgettext:2, dcgettext:2, ngettext:1,2, dngettext:2,3, dcngettext:2,3, and gettext_noop.

`-T'

`--trigraphs'

Understand ANSI C trigraphs for input.

`--debug'

Use the flags c-format and possible-c-format to show who was responsible for marking a message as a format string. The latter form is used if the xgettext program decided, the format form is used if the programmer prescribed it.

By default only the c-format form is used. The translator should not have to care about these details.

This implementation of xgettext is able to process a few awkward cases, like strings in preprocessor macros, ANSI concatenation of adjacent strings, and escaped end of lines for continued strings.

4.1.6 Output details

`--force-po'

Always write an output file even if no message is defined.

`-i'

`--indent'

Write the .po file using indented style.

`--no-location'

Do not write `#: filename:line' lines.

`-n'

`--add-location'

Generate `#: filename:line' lines (default).

`--strict'

Write out a strict Uniforum conforming PO file. Note that this Uniforum format should be avoided because it doesn't support the GNU extensions.

`-w number'

`--width=number'

Set the output page width. Long strings in the output files will be split across multiple lines in order to ensure that each line's width (= number of screen columns) is less or equal to the given number.

`--no-wrap'

Do not break long message lines. Message lines whose width exceeds the output page width will not be split into several lines. Only file reference lines which are wider than the output page width will be split.

`-s'

`--sort-output'

Generate sorted output. Note that using this option makes it much harder for the translator to understand each message's context.

`-F'

`--sort-by-file'

Sort output by file location.

`--omit-header'

Don't write header with `msgid ""' entry.

This is useful for testing purposes because it eliminates a source of variance for generated .gmo files. With --omit-header, two invocations of xgettext on the same files with the same options at different times are guaranteed to produce the same results.

`--copyright-holder=string'

Set the copyright holder in the output. string should be the copyright holder of the surrounding package. (Note that the msgstr strings, extracted from the package's sources, belong to the copyright holder of the package.) Translators are expected to transfer or disclaim the copyright for their translations, so that package maintainers can distribute them without legal risk. If string is empty, the output files are marked as being in the public domain; in this case, the translators are expected to disclaim their copyright, again so that package maintainers can distribute them without legal risk.

The default value for string is the Free Software Foundation, Inc., simply because xgettext was first used in the GNU project.

`--foreign-user'

Omit FSF copyright in output. This option is equivalent to `--copyright-holder="'. It can be useful for packages outside the GNU project that want their translations to be in the public domain.

`-m [string]'

`--msgstr-prefix[=string]'

Use string (or "" if not specified) as prefix for msgstr entries.

`-M [string]'

`--msgstr-suffix[=string]'

Use string (or "" if not specified) as suffix for msgstr entries.

4.1.7 Informative output

`-h'

`--help'

Display this help and exit.

`-V'

`--version'

Output version information and exit.