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catgets.c revision 1.8.2.1 
      1 /*	$NetBSD: catgets.c,v 1.8.2.1 1996/09/16 18:40:55 jtc 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 REGENTS OR CONTRIBUTORS BE
     30  * 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 #define _NLS_PRIVATE
     40 
     41 #include "namespace.h"
     42 #include <stdlib.h>
     43 #include <string.h>
     44 #include <nl_types.h>
     45 
     46 #ifdef __weak_alias
     47 __weak_alias(catgets,_catgets);
     48 #endif
     49 
     50 char *
     51 catgets(catd, set_id, msg_id, s)
     52 	nl_catd catd;
     53 	int set_id;
     54 	int msg_id;
     55 	const char *s;
     56 {
     57 	struct _nls_cat_hdr *cat_hdr;
     58 	struct _nls_set_hdr *set_hdr;
     59 	struct _nls_msg_hdr *msg_hdr;
     60 	int l, u, i, r;
     61 
     62 	if (catd == (nl_catd) 0 || catd == (nl_catd) -1) {
     63 		return (char *) s;
     64 	}
     65 
     66 	cat_hdr = (struct _nls_cat_hdr *) catd->__data;
     67 	set_hdr = (struct _nls_set_hdr *) (catd->__data
     68 		+ sizeof(struct _nls_cat_hdr));
     69 
     70 	/* binary search, see knuth algorithm b */
     71 	l = 0;
     72 	u = ntohl(cat_hdr->__nsets) - 1;
     73 	while (l <= u) {
     74 		i = (l + u) / 2;
     75 		r = set_id - ntohl(set_hdr[i].__setno);
     76 
     77 		if (r == 0) {
     78 			msg_hdr = (struct _nls_msg_hdr *) (catd->__data
     79 				+ sizeof(struct _nls_cat_hdr)
     80 				+ ntohl(cat_hdr->__msg_hdr_offset));
     81 
     82 			l = ntohl(set_hdr[i].__index);
     83 			u = l + ntohl(set_hdr[i].__nmsgs) - 1;
     84 			while (l <= u) {
     85 				i = (l + u) / 2;
     86 				r = msg_id - ntohl(msg_hdr[i].__msgno);
     87 				if (r == 0) {
     88 					return (char *) (catd->__data
     89 					    + sizeof(struct _nls_cat_hdr)
     90 					    + ntohl(cat_hdr->__msg_txt_offset)
     91 					    + ntohl(msg_hdr[i].__offset));
     92 				} else if (r < 0) {
     93 					u = i - 1;
     94 				} else {
     95 					l = i + 1;
     96 				}
     97 			}
     98 
     99 			/* not found */
    100 			return (char *) s;
    101 
    102 		} else if (r < 0) {
    103 			u = i - 1;
    104 		} else {
    105 			l = i + 1;
    106 		}
    107 	}
    108 
    109 	/* not found */
    110 	return (char *) s;
    111 }
    112