isc/nls/msgcat.c

	msgcat.c revision ca41b452ede6feaa9d8739ec3cae19389a7b0d03
/*
 * Copyright (C) 1999, 2000  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM 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.
 */

/*
 * Principal Author: Bob Halley
 */

#include <config.h>

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

#include <isc/assertions.h>
#include <isc/msgcat.h>

#ifdef HAVE_CATGETS
#include <nl_types.h>
#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            0x4D436174  /* MCat */
#define VALID_MSGCAT(m)         ((m) != NULL && \
                     (m)->magic == MSGCAT_MAGIC)

void
isc_msgcat_open(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))
            catclose(msgcat->catalog);
#endif
        msgcat->magic = 0;
        free(msgcat);
    }

    *msgcatp = NULL;
}

char *
isc_msgcat_get(isc_msgcat_t *msgcat, int set, int message,
           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
}