This scons tool is a part of scons &t-link-gettext; toolset. It provides scons interface to xgettext(1) program, which extracts internationalized messages from source code. The tool provides &b-POTUpdate; builder to make PO Template files.

POTSUFFIX POTUPDATE_ALIAS XGETTEXTCOM XGETTEXTCOMSTR XGETTEXTFLAGS XGETTEXTFROM XGETTEXTFROMPREFIX XGETTEXTFROMSUFFIX XGETTEXTPATH XGETTEXTPATHPREFIX XGETTEXTPATHSUFFIX _XGETTEXTDOMAIN _XGETTEXTFROMFLAGS _XGETTEXTPATHFLAGS POTDOMAIN

The builder belongs to &t-link-xgettext; tool. The builder updates target POT file if exists or creates one if it doesn't. The node is not built by default (i.e. it is Ignored from '.'), but only on demand (i.e. when given POT file is required or when special alias is invoked). This builder adds its targe node (messages.pot, say) to a special alias (pot-update by default, see &cv-link-POTUPDATE_ALIAS;) so you can update/create them easily with scons pot-update. The file is not written until there is no real change in internationalized messages (or in comments that enter POT file). You may see xgettext(1) being invoked by the &t-link-xgettext; tool even if there is no real change in internationalized messages (so the POT file is not being updated). This happens every time a source file has changed. In such case we invoke xgettext(1) and compare its output with the content of POT file to decide whether the file should be updated or not. Example 1. Let's create po/ directory and place following SConstruct script there: # SConstruct in 'po/' subdir env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(['foo'], ['../a.cpp', '../b.cpp']) env.POTUpdate(['bar'], ['../c.cpp', '../d.cpp']) Then invoke scons few times: user@host:$ scons # Does not create foo.pot nor bar.pot user@host:$ scons foo.pot # Updates or creates foo.pot user@host:$ scons pot-update # Updates or creates foo.pot and bar.pot user@host:$ scons -c # Does not clean foo.pot nor bar.pot. the results shall be as the comments above say. Example 2. The &b-POTUpdate; builder may be used with no target specified, in which case default target messages.pot will be used. The default target may also be overriden by setting &cv-link-POTDOMAIN; construction variable or providing it as an override to &b-POTUpdate; builder: # SConstruct script env = Environment( tools = ['default', 'xgettext'] ) env['POTDOMAIN'] = "foo" env.POTUpdate(source = ["a.cpp", "b.cpp"]) # Creates foo.pot ... env.POTUpdate(POTDOMAIN = "bar", source = ["c.cpp", "d.cpp"]) # and bar.pot Example 3. The sources may be specified within separate file, for example POTFILES.in: # POTFILES.in in 'po/' subdirectory ../a.cpp ../b.cpp # end of file The name of the file (POTFILES.in) containing the list of sources is provided via &cv-link-XGETTEXTFROM;: # SConstruct file in 'po/' subdirectory env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(XGETTEXTFROM = 'POTFILES.in') Example 4. You may use &cv-link-XGETTEXTPATH; to define source search path. Assume, for example, that you have files a.cpp, b.cpp, po/SConstruct, po/POTFILES.in. Then your POT-related files could look as below: # POTFILES.in in 'po/' subdirectory a.cpp b.cpp # end of file # SConstruct file in 'po/' subdirectory env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(XGETTEXTFROM = 'POTFILES.in', XGETTEXTPATH='../') Example 5. Multiple search directories may be defined within a list, i.e. XGETTEXTPATH = ['dir1', 'dir2', ...]. The order in the list determines the search order of source files. The path to the first file found is used. Let's create 0/1/po/SConstruct script: # SConstruct file in '0/1/po/' subdirectory env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(XGETTEXTFROM = 'POTFILES.in', XGETTEXTPATH=['../', '../../']) and 0/1/po/POTFILES.in: # POTFILES.in in '0/1/po/' subdirectory a.cpp # end of file Write two *.cpp files, the first one is 0/a.cpp: /* 0/a.cpp */ gettext("Hello from ../../a.cpp") and the second is 0/1/a.cpp: /* 0/1/a.cpp */ gettext("Hello from ../a.cpp") then run scons. You'll obtain 0/1/po/messages.pot with the message "Hello from ../a.cpp". When you reverse order in $XGETTEXTFOM, i.e. when you write SConscript as # SConstruct file in '0/1/po/' subdirectory env = Environment( tools = ['default', 'xgettext'] ) env.POTUpdate(XGETTEXTFROM = 'POTFILES.in', XGETTEXTPATH=['../../', '../']) then the messages.pot will contain msgid "Hello from ../../a.cpp" line and not msgid "Hello from ../a.cpp".

Suffix used for PO Template files (default: '.pot'). See &t-link-xgettext; tool and &b-link-POTUpdate; builder.

Name of the common phony target for all PO Templates created with &b-link-POUpdate; (default: 'pot-update'). See &t-link-xgettext; tool and &b-link-POTUpdate; builder.

Path to xgettext(1) program (found via Detect()). See &t-link-xgettext; tool and &b-link-POTUpdate; builder.

Complete xgettext command line. See &t-link-xgettext; tool and &b-link-POTUpdate; builder.

A string that is shown when xgettext(1) command is invoked (default: '', which means "print &cv-link-XGETTEXTCOM;"). See &t-link-xgettext; tool and &b-link-POTUpdate; builder.

Additional flags to xgettext(1). See &t-link-xgettext; tool and &b-link-POTUpdate; builder.

Name of file containing list of xgettext(1)'s source files. Autotools' users know this as POTFILES.in so they will in most cases set XGETTEXTFROM="POTFILES.in" here. The &cv-XGETTEXTFROM; files have same syntax and semantics as the well known GNU POTFILES.in. See &t-link-xgettext; tool and &b-link-POTUpdate; builder.

List of directories, there xgettext(1) will look for source files (default: []). This variable works only together with &cv-link-XGETTEXTFROM; See also &t-link-xgettext; tool and &b-link-POTUpdate; builder.

This flag is used to add single search path to xgettext(1)'s commandline (default: '-D').

(default: '')

This flag is used to add single &cv-link-XGETTEXTFROM; file to xgettext(1)'s commandline (default: '-f').

(default: '')

Internal "macro". Generates xgettext domain name form source and target (default: '${TARGET.filebase}').

Internal "macro". Genrates list of -D<dir> flags from the &cv-link-XGETTEXTPATH; list.

Internal "macro". Generates list of -f<file> flags from &cv-link-XGETTEXTFROM;.