isc/nls/msgcat.c

/*
 * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: msgcat.c,v 1.18 2007/06/19 23:47:18 tbox Exp $ */

/*! \file msgcat.c
 *
 * \author Principal Author: Bob Halley
 */

#include <config.h>

#include <stddef.h>
#include <stdlib.h>

#include <isc/magic.h>
#include <isc/msgcat.h>
#include <isc/util.h>

#ifdef HAVE_CATGETS
#include <nl_types.h>       /* Required for nl_catd. */
#endif

/*
 * Implementation Notes:
 *
 *  We use malloc() and free() instead of isc_mem_get() and isc_mem_put()
 *  because we don't want to require a memory context to be specified
 *  in order to use a message catalog.
 */

struct isc_msgcat {
    unsigned int    magic;
#ifdef HAVE_CATGETS
    nl_catd     catalog;
#endif
};

#define MSGCAT_MAGIC            ISC_MAGIC('M', 'C', 'a', 't')
#define VALID_MSGCAT(m)         ISC_MAGIC_VALID(m, MSGCAT_MAGIC)

void
isc_msgcat_open(const char *name, isc_msgcat_t **msgcatp) {
    isc_msgcat_t *msgcat;

    /*
     * Open a message catalog.
     */

    REQUIRE(name != NULL);
    REQUIRE(msgcatp != NULL && *msgcatp == NULL);

    msgcat = malloc(sizeof(*msgcat));
    if (msgcat == NULL) {
        *msgcatp = NULL;
        return;
    }

#ifdef HAVE_CATGETS
    /*
     * We don't check if catopen() fails because we don't care.
     * If it does fail, then when we call catgets(), it will use
     * the default string.
     */
    msgcat->catalog = catopen(name, 0);
#endif
    msgcat->magic = MSGCAT_MAGIC;

    *msgcatp = msgcat;
}

void
isc_msgcat_close(isc_msgcat_t **msgcatp) {
    isc_msgcat_t *msgcat;

    /*
     * Close a message catalog.
     */

    REQUIRE(msgcatp != NULL);
    msgcat = *msgcatp;
    REQUIRE(VALID_MSGCAT(msgcat) || msgcat == NULL);

    if (msgcat != NULL) {
#ifdef HAVE_CATGETS
        if (msgcat->catalog != (nl_catd)(-1))
            (void)catclose(msgcat->catalog);
#endif
        msgcat->magic = 0;
        free(msgcat);
    }

    *msgcatp = NULL;
}

const char *
isc_msgcat_get(isc_msgcat_t *msgcat, int set, int message,
           const char *default_text)
{
    /*
     * Get message 'message' from message set 'set' in 'msgcat'.  If it
     * is not available, use 'default'.
     */

    REQUIRE(VALID_MSGCAT(msgcat) || msgcat == NULL);
    REQUIRE(set > 0);
    REQUIRE(message > 0);
    REQUIRE(default_text != NULL);

#ifdef HAVE_CATGETS
    if (msgcat == NULL)
        return (default_text);
    return (catgets(msgcat->catalog, set, message, default_text));
#else
    return (default_text);
#endif
}