AM_GNU_GETTEXT macro tests for the presence of the GNU gettext
function family in either the C library or a separate
library (shared or static libraries are both supported). It also invokes
AM_PO_SUBDIRS, thus preparing the po/ directories of the
package for building.
AM_GNU_GETTEXT accepts up to two optional arguments. The general
intlsymbol should always be ‘external’.
If needsymbol is specified and is ‘need-ngettext’, then GNU
gettext implementations (in libc or libintl) without the
function will be ignored. If needsymbol is specified and is
‘need-formatstring-macros’, then GNU gettext implementations that don’t
support the ISO C 99 <inttypes.h> formatstring macros will be ignored.
Only one needsymbol can be specified. These requirements can also be
specified by using the macro
AM_GNU_GETTEXT_NEED elsewhere. To specify
more than one requirement, just specify the strongest one among them, or
AM_GNU_GETTEXT_NEED macro several times. The hierarchy
among the various alternatives is as follows: ‘need-formatstring-macros’
AM_GNU_GETTEXT macro determines whether GNU gettext is
available and should be used. If so, it sets the
to ‘yes’; it defines
ENABLE_NLS to 1 in the autoconf
generated configuration file (usually called config.h); it sets
LTLIBINTL to the linker options
for use in a Makefile (
LIBINTL for use without libtool,
LTLIBINTL for use with libtool); it adds an ‘-I’ option to
CPPFLAGS if necessary. In the negative case, it sets
USE_NLS to ‘no’; it sets
to empty and doesn’t change
The complexities that
AM_GNU_GETTEXT deals with are the following:
gettextin the C library, for example glibc. Some have it in a separate library
libintlmight have been installed as part of the GNU
libintl, if installed, is not necessarily already in the search path (
CPPFLAGSfor the include file search path,
LDFLAGSfor the library search path).
gettextcannot exploit the GNU mo files, doesn’t have the necessary locale dependency features, and cannot convert messages from the catalog’s text encoding to the user’s locale encoding.
libintl, if installed, is not necessarily already in the run time library search path. To avoid the need for setting an environment variable like
LD_LIBRARY_PATH, the macro adds the appropriate run time search path options to the
LTLIBINTLvariables. This works on most systems, but not on some operating systems with limited shared library support, like SCO.
libintlrelies on POSIX/XSI
iconv. The macro checks for linker options needed to use iconv and appends them to the
AM_GNU_GETTEXT macro sets two variables, for
convenience. Both are derived from the
option. They are correct even on native Windows, where directories
frequently contain backslashes.
This is the value of
localedir, in C syntax. This variable is
meant to be substituted into C or C++ code through
This is the value of
localedir, in C syntax, escaped for use in
Makefile. This variable is meant to be used in Makefiles,
for example for defining a C macro named
AM_CPPFLAGS = ... -DLOCALEDIR=$(localedir_c_make) ...