Load X/Open message catalogs

This is going to enable making changes to ERR and RPL messages without
modifying the source code.

Localized messages could be interesting. :)

src/kike.c

@@ -22,6 +22,7 @@
 #define PROGRAM_VERSION "alpha"
 
 #include "common.c"
+#include <nl_types.h>
 
 // --- Configuration (application-specific) ------------------------------------
 
@@ -29,6 +30,7 @@ static struct config_item g_config_table[] =
 {
 	{ "server_name",     NULL,              "Server name"                    },
 	{ "motd",            NULL,              "MOTD filename"                  },
+	{ "catalog",         NULL,              "catgets localization catalog"   },
 
 	{ "bind_host",       NULL,              "Address of the IRC server"      },
 	{ "bind_port",       "6667",            "Port of the IRC server"         },
@@ -325,6 +327,7 @@ struct server_context
 	bool polling;                       ///< The event loop is running
 
 	struct str_vector motd;             ///< MOTD (none if empty)
+	nl_catd catalog;                    ///< Message catalog for server msgs
 };
 
 static void
@@ -347,6 +350,7 @@ server_context_init (struct server_context *self)
 	self->polling = false;
 
 	str_vector_init (&self->motd);
+	self->catalog = (nl_catd) -1;
 }
 
 static void
@@ -374,6 +378,8 @@ server_context_free (struct server_context *self)
 	poller_free (&self->poller);
 
 	str_vector_free (&self->motd);
+	if (self->catalog != (nl_catd) -1)
+		catclose (self->catalog);
 }
 
 // --- Main program ------------------------------------------------------------
@@ -794,6 +800,24 @@ error_ssl_1:
 	return false;
 }
 
+static bool
+irc_initialize_catalog (struct server_context *ctx, struct error **e)
+{
+	hard_assert (ctx->catalog == (nl_catd) -1);
+	const char *catalog = str_map_find (&ctx->config, "catalog");
+	if (!catalog)
+		return true;
+
+	ctx->catalog = catopen (catalog, NL_CAT_LOCALE);
+	if (ctx->catalog == (nl_catd) -1)
+	{
+		error_set (e, IO_ERROR, IO_ERROR_FAILED, "%s: %s",
+			"failed reading the message catalog file", strerror (errno));
+		return false;
+	}
+	return true;
+}
+
 static bool
 irc_initialize_motd (struct server_context *ctx, struct error **e)
 {
@@ -1046,7 +1070,8 @@ main (int argc, char *argv[])
 
 	if (!irc_initialize_ssl (&ctx))
 		exit (EXIT_FAILURE);
-	if (!irc_listen (&ctx, &e))
+	if (!irc_initialize_catalog (&ctx, &e)
+	 || !irc_listen (&ctx, &e))
 	{
 		print_error ("%s", e->message);
 		error_free (e);