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catgets.c revision 1.17 
      1 /*	$NetBSD: catgets.c,v 1.17 2005/11/29 03:12:00 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by J.T. Conklin.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 #if defined(LIBC_SCCS) && !defined(lint)
     41 __RCSID("$NetBSD: catgets.c,v 1.17 2005/11/29 03:12:00 christos Exp $");
     42 #endif /* LIBC_SCCS and not lint */
     43 
     44 #define _NLS_PRIVATE
     45 
     46 #include "namespace.h"
     47 #include <errno.h>
     48 #include <stdlib.h>
     49 #include <string.h>
     50 #include <nl_types.h>
     51 
     52 #ifdef __weak_alias
     53 __weak_alias(catgets, _catgets)
     54 #endif
     55 
     56 char *
     57 _catgets(catd, set_id, msg_id, s)
     58 	nl_catd catd;
     59 	int set_id;
     60 	int msg_id;
     61 	const char *s;
     62 {
     63 	struct _nls_cat_hdr *cat_hdr;
     64 	struct _nls_set_hdr *set_hdr;
     65 	struct _nls_msg_hdr *msg_hdr;
     66 	int l, u, i, r;
     67 
     68 	if (catd == (nl_catd) -1) {
     69 		errno = EBADF;
     70 		return __UNCONST(s);
     71 	}
     72 
     73 	cat_hdr = (struct _nls_cat_hdr *)catd->__data;
     74 	set_hdr = (struct _nls_set_hdr *)(void *)((char *)catd->__data
     75 		+ sizeof(struct _nls_cat_hdr));
     76 
     77 	/* binary search, see knuth algorithm b */
     78 	l = 0;
     79 	u = ntohl((u_int32_t)cat_hdr->__nsets) - 1;
     80 	while (l <= u) {
     81 		i = (l + u) / 2;
     82 		r = set_id - ntohl((u_int32_t)set_hdr[i].__setno);
     83 
     84 		if (r == 0) {
     85 			msg_hdr = (struct _nls_msg_hdr *)
     86 			    (void *)((char *)catd->__data +
     87 			    sizeof(struct _nls_cat_hdr) +
     88 			    ntohl((u_int32_t)cat_hdr->__msg_hdr_offset));
     89 
     90 			l = ntohl((u_int32_t)set_hdr[i].__index);
     91 			u = l + ntohl((u_int32_t)set_hdr[i].__nmsgs) - 1;
     92 			while (l <= u) {
     93 				i = (l + u) / 2;
     94 				r = msg_id -
     95 				    ntohl((u_int32_t)msg_hdr[i].__msgno);
     96 				if (r == 0) {
     97 					return ((char *) catd->__data +
     98 					    sizeof(struct _nls_cat_hdr) +
     99 					    ntohl((u_int32_t)
    100 					    cat_hdr->__msg_txt_offset) +
    101 					    ntohl((u_int32_t)
    102 					    msg_hdr[i].__offset));
    103 				} else if (r < 0) {
    104 					u = i - 1;
    105 				} else {
    106 					l = i + 1;
    107 				}
    108 			}
    109 
    110 			/* not found */
    111 			goto notfound;
    112 
    113 		} else if (r < 0) {
    114 			u = i - 1;
    115 		} else {
    116 			l = i + 1;
    117 		}
    118 	}
    119 
    120 notfound:
    121 	/* not found */
    122 	errno = ENOMSG;
    123 	return __UNCONST(s);
    124 }
    125