xref: /netbsd-src/lib/libc/nls/catgets.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: catgets.c,v 1.12 1997/07/30 23:49:48 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 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 #define _NLS_PRIVATE
40 
41 #include "namespace.h"
42 #include <errno.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <nl_types.h>
46 
47 char *
48 _catgets(catd, set_id, msg_id, s)
49 	nl_catd catd;
50 	int set_id;
51 	int msg_id;
52 	const char *s;
53 {
54 	struct _nls_cat_hdr *cat_hdr;
55 	struct _nls_set_hdr *set_hdr;
56 	struct _nls_msg_hdr *msg_hdr;
57 	int l, u, i, r;
58 
59 	if (catd == (nl_catd) -1) {
60 		errno = EBADF;
61 		return (char *) s;
62 	}
63 
64 	cat_hdr = (struct _nls_cat_hdr *) catd->__data;
65 	set_hdr = (struct _nls_set_hdr *) ((char *) catd->__data
66 		+ sizeof(struct _nls_cat_hdr));
67 
68 	/* binary search, see knuth algorithm b */
69 	l = 0;
70 	u = ntohl(cat_hdr->__nsets) - 1;
71 	while (l <= u) {
72 		i = (l + u) / 2;
73 		r = set_id - ntohl(set_hdr[i].__setno);
74 
75 		if (r == 0) {
76 			msg_hdr = (struct _nls_msg_hdr *) ((char *)catd->__data
77 				+ sizeof(struct _nls_cat_hdr)
78 				+ ntohl(cat_hdr->__msg_hdr_offset));
79 
80 			l = ntohl(set_hdr[i].__index);
81 			u = l + ntohl(set_hdr[i].__nmsgs) - 1;
82 			while (l <= u) {
83 				i = (l + u) / 2;
84 				r = msg_id - ntohl(msg_hdr[i].__msgno);
85 				if (r == 0) {
86 					return ((char *) catd->__data
87 					    + sizeof(struct _nls_cat_hdr)
88 					    + ntohl(cat_hdr->__msg_txt_offset)
89 					    + ntohl(msg_hdr[i].__offset));
90 				} else if (r < 0) {
91 					u = i - 1;
92 				} else {
93 					l = i + 1;
94 				}
95 			}
96 
97 			/* not found */
98 			return (char *) s;
99 
100 		} else if (r < 0) {
101 			u = i - 1;
102 		} else {
103 			l = i + 1;
104 		}
105 	}
106 
107 	/* not found */
108 	return (char *) s;
109 }
110