Gettext/xgettext-Invocation
5.1 Invoking the xgettext
Program
xgettext [option] [inputfile] …
The xgettext
program extracts translatable strings from given
input files.
5.1.1 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.
5.1.2 Output file location
- ‘
-d name
’
‘--default-domain=name
’ Use
name.po
for output (instead ofmessages.po
).- ‘
-o file
’
‘--output=file
’ Write output to specified file (instead of
name.po
ormessages.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.
5.1.3 Choice of input file language
- ‘
-L name
’
‘--language=name
’ Specifies the language of the input files. The supported languages are
C
,C++
,ObjectiveC
,PO
,Shell
,Python
,Lisp
,EmacsLisp
,librep
,Scheme
,Smalltalk
,Java
,JavaProperties
,C#
,awk
,YCP
,Tcl
,Perl
,PHP
,Ruby
,GCC-source
,NXStringTable
,RST
,RSJ
,Glade
,Lua
,JavaScript
,Vala
,GSettings
,Desktop
.- ‘
-C
’
‘--c++
’ This is a shorthand for
--language=C++
.
By default the language is guessed depending on the input file name extension.
5.1.4 Input file interpretation
- ‘
--from-code=name
’ Specifies the encoding of the input files. This option is needed only if some untranslated message strings or their corresponding comments contain non-ASCII characters. Note that Tcl and Glade input files are always assumed to be in UTF-8, regardless of this option.
By default the input files are assumed to be in ASCII.
5.1.5 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 blocks starting with
tag
and preceding keyword lines in the output file. Without atag
, the option means to put all comment blocks preceding keyword lines in the output file.Note that comment blocks supposed to be extracted must be adjacent to keyword lines. For example, in the following C source code:
/* This is the first comment. */ gettext ("foo"); /* This is the second comment: not extracted */ gettext ( "bar"); gettext ( /* This is the third comment. */ "baz");
The second comment line will not be extracted, because there is one blank line between the comment line and the keyword.
- ‘
--check[=CHECK]
’ Perform a syntax check on msgid and msgid_plural. The supported checks are:
- ‘
ellipsis-unicode
’ Prefer Unicode ellipsis character over ASCII
...
- ‘
space-ellipsis
’ Prohibit whitespace before an ellipsis character
- ‘
quote-unicode
’ Prefer Unicode quotation marks over ASCII
"'`
- ‘
bullet-unicode
’ Prefer Unicode bullet character over ASCII
*
or-
The option has an effect on all input files. To enable or disable checks for a certain string, you can mark it with an
xgettext:
special comment in the source file. For example, if you specify the--check=space-ellipsis
option, but want to suppress the check on a particular string, add the following comment:/* xgettext: no-space-ellipsis-check */ gettext ("We really want a space before ellipsis here ...");
The
xgettext:
comment can be followed by flags separated with a comma. The possible flags are of the form ‘[no-]name-check
’, wherename
is the name of a valid syntax check. If a flag is prefixed byno-
, the meaning is negated.Some tests apply the checks to each sentence within the msgid, rather than the whole string. xgettext detects the end of sentence by performing a pattern match, which usually looks for a period followed by a certain number of spaces. The number is specified with the
--sentence-end
option.- ‘
- ‘
--sentence-end[=TYPE]
’ The supported values are:
- ‘
single-space
’ Expect at least one whitespace after a period
- ‘
double-space
’ Expect at least two whitespaces after a period
- ‘
5.1.6 Language specific options
- ‘
-a
’
‘--extract-all
’ Extract all strings.
This option has an effect with most languages, namely C, C++, ObjectiveC, Shell, Python, Lisp, EmacsLisp, librep, Java, C#, awk, Tcl, Perl, PHP, GCC-source, Glade, Lua, JavaScript, Vala, GSettings.
- ‘
-k[keywordspec]
’
‘--keyword[=keywordspec]
’ Specify
keywordspec
as an additional keyword to be looked for. Without akeywordspec
, the option means to not use default keywords.If
keywordspec
is a C identifierid
,xgettext
looks for strings in the first argument of each call to the function or macroid
. Ifkeywordspec
is of the form ‘id:argnum
’,xgettext
looks for strings in theargnum
th argument of the call. Ifkeywordspec
is of the form ‘id:argnum1,argnum2
’,xgettext
looks for strings in theargnum1
st argument and in theargnum2
nd argument of the call, and treats them as singular/plural variants for a message with plural handling. Also, ifkeywordspec
is of the form ‘id:contextargnumc,argnum
’ or ‘id:argnum,contextargnumc
’,xgettext
treats strings in thecontextargnum
th argument as a context specifier. And, as a special-purpose support for GNOME, ifkeywordspec
is of the form ‘id:argnumg
’,xgettext
recognizes theargnum
th argument as a string with context, using the GNOMEglib
syntax ‘"msgctxt|msgid"
’. Furthermore, ifkeywordspec
is of the form ‘id:…,totalnumargst
’,xgettext
recognizes this argument specification only if the number of actual arguments is equal tototalnumargs
. This is useful for disambiguating overloaded function calls in C++. Finally, ifkeywordspec
is of the form ‘id:argnum...,"xcomment"
’,xgettext
, when extracting a message from the specified argument strings, adds an extracted commentxcomment
to the message. Note that when used through a normal shell command line, the double-quotes around thexcomment
need to be escaped.This option has an effect with most languages, namely C, C++, ObjectiveC, Shell, Python, Lisp, EmacsLisp, librep, Java, C#, awk, Tcl, Perl, PHP, GCC-source, Glade, Lua, JavaScript, Vala, GSettings, Desktop.
The default keyword specifications, which are always looked for if not explicitly disabled, are language dependent. They are:
- For C, C++, and GCC-source:
gettext
,dgettext:2
,dcgettext:2
,ngettext:1,2
,dngettext:2,3
,dcngettext:2,3
,gettext_noop
, andpgettext:1c,2
,dpgettext:2c,3
,dcpgettext:2c,3
,npgettext:1c,2,3
,dnpgettext:2c,3,4
,dcnpgettext:2c,3,4
. - For Objective C: Like for C, and also
NSLocalizedString
,_
,NSLocalizedStaticString
,__
. - For Shell scripts:
gettext
,ngettext:1,2
,eval_gettext
,eval_ngettext:1,2
,eval_pgettext:1c,2
,eval_npgettext:1c,2,3
. - For Python:
gettext
,ugettext
,dgettext:2
,ngettext:1,2
,ungettext:1,2
,dngettext:2,3
,_
. - For Lisp:
gettext
,ngettext:1,2
,gettext-noop
. - For EmacsLisp:
_
. - For librep:
_
. - For Scheme:
gettext
,ngettext:1,2
,gettext-noop
. - For Java:
GettextResource.gettext:2
,GettextResource.ngettext:2,3
,GettextResource.pgettext:2c,3
,GettextResource.npgettext:2c,3,4
,gettext
,ngettext:1,2
,pgettext:1c,2
,npgettext:1c,2,3
,getString
. - For C#:
GetString
,GetPluralString:1,2
,GetParticularString:1c,2
,GetParticularPluralString:1c,2,3
. - For awk:
dcgettext
,dcngettext:1,2
. - For Tcl:
::msgcat::mc
. - For Perl:
gettext
,%gettext
,$gettext
,dgettext:2
,dcgettext:2
,ngettext:1,2
,dngettext:2,3
,dcngettext:2,3
,gettext_noop
. - For PHP:
_
,gettext
,dgettext:2
,dcgettext:2
,ngettext:1,2
,dngettext:2,3
,dcngettext:2,3
. - For Glade 1:
label
,title
,text
,format
,copyright
,comments
,preview_text
,tooltip
. - For Lua:
_
,gettext.gettext
,gettext.dgettext:2
,gettext.dcgettext:2
,gettext.ngettext:1,2
,gettext.dngettext:2,3
,gettext.dcngettext:2,3
. - For JavaScript:
_
,gettext
,dgettext:2
,dcgettext:2
,ngettext:1,2
,dngettext:2,3
,pgettext:1c,2
,dpgettext:2c,3
. - For Vala:
_
,Q_
,N_
,NC_
,dgettext:2
,dcgettext:2
,ngettext:1,2
,dngettext:2,3
,dpgettext:2c,3
,dpgettext2:2c,3
. - For Desktop:
Name
,GenericName
,Comment
,Keywords
.
To disable the default keyword specifications, the option ‘
-k
’ or ‘--keyword
’ or ‘--keyword=
’, without akeywordspec
, can be used.- For C, C++, and GCC-source:
- ‘
--flag=word:arg:flag
’ Specifies additional flags for strings occurring as part of the
arg
th argument of the functionword
. The possible flags are the possible format string indicators, such as ‘c-format
’, and their negations, such as ‘no-c-format
’, possibly prefixed with ‘pass-
’. The meaning of--flag=function:arg:lang-format
is that in languagelang
, the specifiedfunction
expects asarg
th argument a format string. (For those of you familiar with GCC function attributes,--flag=function:arg:c-format
is roughly equivalent to the declaration ‘__attribute__ ((__format__ (__printf__, arg, ...)))
’ attached tofunction
in a C source file.) For example, if you use the ‘error
’ function from GNU libc, you can specify its behaviour through--flag=error:3:c-format
. The effect of this specification is thatxgettext
will mark as format strings allgettext
invocations that occur asarg
th argument offunction
. This is useful when such strings contain no format string directives: together with the checks done by ‘msgfmt -c
’ it will ensure that translators cannot accidentally use format string directives that would lead to a crash at runtime. The meaning of--flag=function:arg:pass-lang-format
is that in languagelang
, if thefunction
call occurs in a position that must yield a format string, then itsarg
th argument must yield a format string of the same type as well. (If you know GCC function attributes, the--flag=function:arg:pass-c-format
option is roughly equivalent to the declaration ‘__attribute__ ((__format_arg__ (arg)))
’ attached tofunction
in a C source file.) For example, if you use the ‘_
’ shortcut for thegettext
function, you should use--flag=_:1:pass-c-format
. The effect of this specification is thatxgettext
will propagate a format string requirement for a_("string")
call to its first argument, the literal"string"
, and thus mark it as a format string. This is useful when such strings contain no format string directives: together with the checks done by ‘msgfmt -c
’ it will ensure that translators cannot accidentally use format string directives that would lead to a crash at runtime. This option has an effect with most languages, namely C, C++, ObjectiveC, Shell, Python, Lisp, EmacsLisp, librep, Scheme, Java, C#, awk, YCP, Tcl, Perl, PHP, GCC-source, Lua, JavaScript, Vala.- ‘
-T
’
‘--trigraphs
’ Understand ANSI C trigraphs for input. This option has an effect only with the languages C, C++, ObjectiveC.
- ‘
--qt
’ Recognize Qt format strings. This option has an effect only with the language C++.
- ‘
--kde
’ Recognize KDE 4 format strings. This option has an effect only with the language C++.
- ‘
--boost
’ Recognize Boost format strings. This option has an effect only with the language C++.
- ‘
--debug
’ Use the flags
c-format
andpossible-c-format
to show who was responsible for marking a message as a format string. The latter form is used if thexgettext
program decided, the former 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.
5.1.7 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 no message is defined.
- ‘
-i
’
‘--indent
’ Write the .po file using indented style.
- ‘
--no-location
’ Do not write ‘
#: filename:line
’ lines. Note that using this option makes it harder for technically skilled translators to understand each message’s context.- ‘
-n
’
‘--add-location=type
’ Generate ‘
#: filename:line
’ lines (default).The optional
type
can be either ‘full
’, ‘file
’, or ‘never
’. If it is not given or ‘full
’, it generates the lines with both file name and line number. If it is ‘file
’, the line number part is omitted. If it is ‘never
’, it completely suppresses the lines (same as--no-location
).- ‘
--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.
- ‘
--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.- ‘
--its=file
’ Use ITS rules defined in
file
. Note that this is only effective with XML files.- ‘
--itstool
’ Write out comments recognized by itstool (http://itstool.org). Note that this is only effective with XML files.
- ‘
-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 ofxgettext
on the same files with the same options at different times are guaranteed to produce the same results.Note that using this option will lead to an error if the resulting file would not entirely be in ASCII.
- ‘
--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. Ifstring
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 becausexgettext
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.- ‘
--package-name=package
’ Set the package name in the header of the output.
- ‘
--package-version=version
’ Set the package version in the header of the output. This option has an effect only if the ‘
--package-name
’ option is also used.- ‘
--msgid-bugs-address=email@address
’ Set the reporting address for msgid bugs. This is the email address or URL to which the translators shall report bugs in the untranslated strings:
- - Strings which are not entire sentences; see the maintainer guidelines in Preparing Strings.
- - Strings which use unclear terms or require additional context to be understood.
- - Strings which make invalid assumptions about notation of date, time or money.
- - Pluralisation problems.
- - Incorrect English spelling.
- - Incorrect formatting.
It can be your email address, or a mailing list address where translators can write to without being subscribed, or the URL of a web page through which the translators can contact you.
The default value is empty, which means that translators will be clueless! Don’t forget to specify this option.
- ‘
-m[string]
’
‘--msgstr-prefix[=string]
’ Use
string
(or "" if not specified) as prefix for msgstr values.- ‘
-M[string]
’
‘--msgstr-suffix[=string]
’ Use
string
(or "" if not specified) as suffix for msgstr values.
5.1.8 Informative output
- ‘
-h
’
‘--help
’ Display this help and exit.
- ‘
-V
’
‘--version
’ Output version information and exit.
- ‘
-v
’
‘--verbose
’ Increase verbosity level.