     msgfilter [OPTION] FILTER [FILTER-OPTION]

The msgfilter program applies a filter to all translations of a translation catalog.

During each FILTER invocation, the environment variable MSGFILTER_MSGID is bound to the message's msgid, and the environment variable MSGFILTER_LOCATION is bound to the location in the PO file of the message.  If the message has a context, the environment variable MSGFILTER_MSGCTXT is bound to the message's msgctxt, otherwise it is unbound.

Input file location
-------------------

-i INPUTFILE
--input=INPUTFILE
     Input PO file.

-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 no INPUTFILE is given or if it is -, standard input is read.

Output file location
--------------------

-o FILE
--output-file=FILE
     Write output to specified file.

The results are written to standard output if no output file is specified or if it is -.

The filter
----------

The FILTER can be any program that reads a translation from standard input and writes a modified translation to standard output.  A frequently used filter is sed.  A few particular built-in filters are also recognized.

Note: If the filter is not a built-in filter, you have to care about encodings: It is your responsibility to ensure that the FILTER can cope with input encoded in the translation catalog's encoding.  If the FILTER wants input in a particular encoding, you can in a first step convert the translation catalog to that encoding using the msgconv program, before invoking msgfilter.  If the FILTER wants input in the locale's encoding, but you want to avoid the locale's encoding, then you can first convert the translation catalog to UTF-8 using the msgconv program and then make msgfilter work in an UTF-8 locale, by using the LC_ALL environment variable.

Note: Most translations in a translation catalog don't end with a newline character.  For this reason, it is important that the FILTER recognizes its last input line even if it ends without a newline, and that it doesn't add an undesired trailing newline at the end.  The sed program on some platforms is known to ignore the last line of input if it is not terminated with a newline.  You can use GNU sed instead; it does not have this limitation.

Useful FILTER-OPTIONs when the FILTER is sed
--------------------------------------------

-e SCRIPT
--expression=SCRIPT
     Add SCRIPT to the commands to be executed.

-f SCRIPTFILE
--file=SCRIPTFILE
     Add the contents of SCRIPTFILE to the commands to be executed.

-n
--quiet
--silent
     Suppress automatic printing of pattern space.

Built-in FILTERs
----------------

The filter recode-sr-latin is recognized as a built-in filter. The command recode-sr-latin converts Serbian text, written in the Cyrillic script, to the Latin script. The command msgfilter recode-sr-latin applies this conversion to the translations of a PO file.  Thus, it can be used to convert an sr.po file to an sr@latin.po file.

The use of built-in filters is not sensitive to the current locale's encoding. Moreover, when used with a built-in filter, msgfilter can automatically convert the message catalog to the UTF-8 encoding when needed.

Input file syntax
-----------------

-P
--properties-input
     Assume the input file is a Java ResourceBundle in Java .properties syntax, not in PO file syntax.

--stringtable-input
     Assume the input file is a NeXTstep/GNUstep localized resource file in .strings syntax, not in PO file syntax.

Output details
--------------

--color
--color=WHEN
     Specify whether or when to use colors and other text attributes. See The --color option for details.

--style=STYLE_FILE
     Specify the CSS style rule file to use for --color. See The --style option for details.

--force-po
     Always write an output file even if it contains no message.

--indent
     Write the .po file using indented style.

--keep-header
     Keep the header entry, i.e. the message with msgid "", unmodified, instead of filtering it.  By default, the header entry is subject to filtering like any other message.

--no-location
     Do not write #: FILENAME:LINE lines.

--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.

-p
--properties-output
     Write out a Java ResourceBundle in Java .properties syntax.  Note that this file format doesn't support plural forms and silently drops obsolete messages.

--stringtable-output
     Write out a NeXTstep/GNUstep localized resource file in .strings syntax. Note that this file format doesn't support plural forms.

-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.

Informative output
------------------

-h
--help
     Display this help and exit.

-V
--version
     Output version information and exit.

Examples
--------

To convert German translations to Swiss orthography (in an UTF-8 locale):

     msgconv -t UTF-8 de.po | msgfilter sed -e 's/ß/ss/g'

To convert Serbian translations in Cyrillic script to Latin script:

     msgfilter recode-sr-latin < sr.po