Added i18n example: msgs_i18n.c

AUTHORS

@@ -56,6 +56,7 @@ Robert Groenenberg <robert.groenenberg@broadforward.com>
 Denis Dowling <denis.dowling@hsd.com.au>
 Louis Benoit <louisbenoit@videotron.ca>
 Flavio Coelin <flavio.ceolin@intel.com>
+Silvio Clecio <silvioprog@gmail.com>
 
 Documentation contributions also came from:
 Marco Maggi <marco.maggi-ipsu@poste.it>

src/examples/Makefile.am

@@ -25,6 +25,7 @@ noinst_PROGRAMS = \
  minimal_example_comet \
  querystring_example \
  timeout \
+ msgs_i18n \
  fileserver_example \
  fileserver_example_dirs \
  fileserver_example_external_select \
@@ -73,6 +74,11 @@ timeout_SOURCES = \
 timeout_LDADD = \
  $(top_builddir)/src/microhttpd/libmicrohttpd.la
 
+msgs_i18n_SOURCEs = \
+ msgs_i18n.c
+msgs_i18n_LDADD = \
+ $(top_builddir)/src/microhttpd/libmicrohttpd.la
+
 chunked_example_SOURCES = \
  chunked_example.c
 chunked_example_LDADD = \

src/examples/msgs_i18n.c

@@ -0,0 +1,91 @@
+/*
+     This file is part of libmicrohttpd
+     Copyright (C) 2017 Christian Grothoff, Silvio Clecio (silvioprog)
+
+     This library is free software; you can redistribute it and/or
+     modify it under the terms of the GNU Lesser General Public
+     License as published by the Free Software Foundation; either
+     version 2.1 of the License, or (at your option) any later version.
+
+     This library is distributed in the hope that it will be useful,
+     but WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     Lesser General Public License for more details.
+
+     You should have received a copy of the GNU Lesser General Public
+     License along with this library; if not, write to the Free Software
+     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+/**
+ * @file msgs_i18n.c
+ * @brief example for how to use translate libmicrohttpd messages
+ * @author Christian Grothoff, Silvio Clecio (silvioprog)
+ */
+
+/*
+ * suposing you are in the libmicrohttp root directory and the LANG is `pt_BR`: *
+ *
+ * # generate the POT file
+ * $ xgettext --keyword=_ --language=C --add-comments --sort-output -o libmicrohttpd.pot src/microhttpd/*.c
+ *
+ * # generate the PO file
+ * $ msginit --input=libmicrohttpd.pot --locale=pt_BR --output=libmicrohttpd.po
+ *
+ * # open the generated .po in any program like Poedit and translate the MHD messages; once done, let's go to the test:
+ * mkdir -p src/examples/locale/pt_BR/LC_MESSAGES
+ * mv libmicrohttpd.mo libmicrohttpd.po src/examples/locale/pt_BR/LC_MESSAGES
+ * cd src/examples/
+ * gcc -o msgs_i18n msgs_i18n.c -lmicrohttpd
+ * export LANGUAGE=pt_BR
+ * ./msgs_i18n
+ * # it may print: Opção inválida 4196490! (Você terminou a lista com MHD_OPTION_END?)
+ *
+ * # tip: if you get any problem in your i18n application, you can debug it using `strace` tool, e.g:
+ * $ strace -e trace=open ./msgs_i18n
+ *
+ * That's all!
+ * 
+ */
+
+#include <stdio.h>
+#include <locale.h>
+#include <libintl.h>
+#include <microhttpd.h>
+
+#ifndef _
+#define _(fm) dgettext("libmicrohttpd", fm)
+#endif
+
+static int
+ahc_echo(void *cls,
+         struct MHD_Connection *cnc,
+         const char *url,
+         const char *mt,
+         const char *ver,
+         const char *upd,
+         size_t *upsz,
+         void **ptr) {
+    return MHD_NO;
+}
+
+static void
+error_handler(void *cls,
+              const char *fm,
+              va_list ap) {
+    vprintf(_(fm), ap);
+}
+
+int
+main() {
+    setlocale(LC_ALL, "");
+    /* notice I'm using PO files in the directory "libmicrohttpd/src/examples/locale", please change it matching
+     * where the MHD PO files are installed */
+    bindtextdomain("libmicrohttpd", "locale");
+    MHD_start_daemon(MHD_USE_SELECT_INTERNALLY | MHD_FEATURE_MESSAGES | MHD_USE_ERROR_LOG,
+                     8080,
+                     NULL, NULL,
+                     &ahc_echo, NULL,
+                     MHD_OPTION_EXTERNAL_LOGGER, &error_handler, NULL
+            /* MHD_OPTION_END - to raise the error "Invalid option ..." we are going to translate */);
+    return 1; /* purposely */
+}