gettext, dgettext, dcgettext - translate message
char * gettext (const char * msgid);
char * dgettext (const char * domainname, const char * msgid);
char * dcgettext (const char * domainname, const char * msgid,
The gettext, dgettext and dcgettext functions attempt to translate a
text string into the users native language, by looking up the transla
tion in a message catalog.
The msgid argument identifies the message to be translated. By conven
tion, it is the English version of the message, with non-ASCII charac
ters replaced by ASCII approximations. This choice allows the transla
tors to work with message catalogs, called PO files, that contain both
the English and the translated versions of each message, and can be
installed using the msgfmt utility.
A message domain is a set of translatable msgid messages. Usually,
every software package has its own message domain. The domain name is
used to determine the message catalog where the translation is looked
up; it must be a non-empty string. For the gettext function, it is
specified through a preceding textdomain call. For the dgettext and
dcgettext functions, it is passed as the domainname argument; if this
argument is NULL, the domain name specified through a preceding textdo
main call is used instead.
Translation lookup operates in the context of the current locale. For
the gettext and dgettext functions, the LC_MESSAGES locale facet is
used. It is determined by a preceding call to the setlocale function.
setlocale(LC_ALL,"") initializes the LC_MESSAGES locale based on the
first nonempty value of the three environment variables LC_ALL, LC_MES
SAGES, LANG; see setlocale(3). For the dcgettext function, the locale
facet is determined by the category argument, which should be one of
the LC_xxx constants defined in the header, excluding
LC_ALL. In both cases, the functions also use the LC_CTYPE locale facet
in order to convert the translated message from the translators code
set to the current locales codeset, unless overridden by a prior call
to the bind_textdomain_codeset function.
The message catalog used by the functions is at the pathname
dirname/locale/category/domainname.mo. Here dirname is the directory
specified through bindtextdomain. Its default is system and configura
tion dependent; typically it is prefix/share/locale, where prefix is
the installation prefix of the package. locale is the name of the cur
rent locale facet; the GNU implementation also tries generalizations,
such as the language name without the territory name. category is
LC_MESSAGES for the gettext and dgettext functions, or the argument
passed to the dcgettext function.
If the LANGUAGE environment variable is set to a nonempty value, and
the locale is not the "C" locale, the value of LANGUAGE is assumed to
contain a colon separated list of locale names. The functions will
attempt to look up a translation of msgid in each of the locales in
turn. This is a GNU extension.
In the "C" locale, or if none of the used catalogs contain a
translation for msgid, the gettext, dgettext and dcgettext functions
If a translation was found in one of the specified catalogs, it is con
verted to the locales codeset and returned. The resulting string is
statically allocated and must not be modified or freed. Otherwise msgid
errno is not modified.
The return type ought to be const char *, but is char * to avoid warn
ings in C code predating ANSI C.
When an empty string is used for msgid, the functions may return a
ngettext(3), dngettext(3), dcngettext(3), setlocale(3), textdomain(3),
bindtextdomain(3), bind_textdomain_codeset(3), msgfmt(1)
GNU gettext 0.16.1 May 2001 GETTEXT(3)