xref: /netbsd-src/lib/libc/nls/catgets.c (revision 81b108b45f75f89f1e3ffad9fb6f074e771c0935)
1 /*	$NetBSD: catgets.c,v 1.8 1996/05/13 23:29:38 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 <stdlib.h>
42 #include <string.h>
43 #include <nl_types.h>
44 
45 char *
46 _catgets(catd, set_id, msg_id, s)
47 	nl_catd catd;
48 	int set_id;
49 	int msg_id;
50 	const char *s;
51 {
52 	struct _nls_cat_hdr *cat_hdr;
53 	struct _nls_set_hdr *set_hdr;
54 	struct _nls_msg_hdr *msg_hdr;
55 	int l, u, i, r;
56 
57 	if (catd == (nl_catd) 0 || catd == (nl_catd) -1) {
58 		return (char *) s;
59 	}
60 
61 	cat_hdr = (struct _nls_cat_hdr *) catd->__data;
62 	set_hdr = (struct _nls_set_hdr *) (catd->__data
63 		+ sizeof(struct _nls_cat_hdr));
64 
65 	/* binary search, see knuth algorithm b */
66 	l = 0;
67 	u = ntohl(cat_hdr->__nsets) - 1;
68 	while (l <= u) {
69 		i = (l + u) / 2;
70 		r = set_id - ntohl(set_hdr[i].__setno);
71 
72 		if (r == 0) {
73 			msg_hdr = (struct _nls_msg_hdr *) (catd->__data
74 				+ sizeof(struct _nls_cat_hdr)
75 				+ ntohl(cat_hdr->__msg_hdr_offset));
76 
77 			l = ntohl(set_hdr[i].__index);
78 			u = l + ntohl(set_hdr[i].__nmsgs) - 1;
79 			while (l <= u) {
80 				i = (l + u) / 2;
81 				r = msg_id - ntohl(msg_hdr[i].__msgno);
82 				if (r == 0) {
83 					return (char *) (catd->__data
84 					    + sizeof(struct _nls_cat_hdr)
85 					    + ntohl(cat_hdr->__msg_txt_offset)
86 					    + ntohl(msg_hdr[i].__offset));
87 				} else if (r < 0) {
88 					u = i - 1;
89 				} else {
90 					l = i + 1;
91 				}
92 			}
93 
94 			/* not found */
95 			return (char *) s;
96 
97 		} else if (r < 0) {
98 			u = i - 1;
99 		} else {
100 			l = i + 1;
101 		}
102 	}
103 
104 	/* not found */
105 	return (char *) s;
106 }
107