xref: /netbsd-src/lib/libc/nls/catgets.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: catgets.c,v 1.18 2008/04/28 20:23:00 martin 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 __RCSID("$NetBSD: catgets.c,v 1.18 2008/04/28 20:23:00 martin Exp $");
35 #endif /* LIBC_SCCS and not lint */
36 
37 #define _NLS_PRIVATE
38 
39 #include "namespace.h"
40 #include <errno.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <nl_types.h>
44 
45 #ifdef __weak_alias
46 __weak_alias(catgets, _catgets)
47 #endif
48 
49 char *
50 _catgets(catd, set_id, msg_id, s)
51 	nl_catd catd;
52 	int set_id;
53 	int msg_id;
54 	const char *s;
55 {
56 	struct _nls_cat_hdr *cat_hdr;
57 	struct _nls_set_hdr *set_hdr;
58 	struct _nls_msg_hdr *msg_hdr;
59 	int l, u, i, r;
60 
61 	if (catd == (nl_catd) -1) {
62 		errno = EBADF;
63 		return __UNCONST(s);
64 	}
65 
66 	cat_hdr = (struct _nls_cat_hdr *)catd->__data;
67 	set_hdr = (struct _nls_set_hdr *)(void *)((char *)catd->__data
68 		+ sizeof(struct _nls_cat_hdr));
69 
70 	/* binary search, see knuth algorithm b */
71 	l = 0;
72 	u = ntohl((u_int32_t)cat_hdr->__nsets) - 1;
73 	while (l <= u) {
74 		i = (l + u) / 2;
75 		r = set_id - ntohl((u_int32_t)set_hdr[i].__setno);
76 
77 		if (r == 0) {
78 			msg_hdr = (struct _nls_msg_hdr *)
79 			    (void *)((char *)catd->__data +
80 			    sizeof(struct _nls_cat_hdr) +
81 			    ntohl((u_int32_t)cat_hdr->__msg_hdr_offset));
82 
83 			l = ntohl((u_int32_t)set_hdr[i].__index);
84 			u = l + ntohl((u_int32_t)set_hdr[i].__nmsgs) - 1;
85 			while (l <= u) {
86 				i = (l + u) / 2;
87 				r = msg_id -
88 				    ntohl((u_int32_t)msg_hdr[i].__msgno);
89 				if (r == 0) {
90 					return ((char *) catd->__data +
91 					    sizeof(struct _nls_cat_hdr) +
92 					    ntohl((u_int32_t)
93 					    cat_hdr->__msg_txt_offset) +
94 					    ntohl((u_int32_t)
95 					    msg_hdr[i].__offset));
96 				} else if (r < 0) {
97 					u = i - 1;
98 				} else {
99 					l = i + 1;
100 				}
101 			}
102 
103 			/* not found */
104 			goto notfound;
105 
106 		} else if (r < 0) {
107 			u = i - 1;
108 		} else {
109 			l = i + 1;
110 		}
111 	}
112 
113 notfound:
114 	/* not found */
115 	errno = ENOMSG;
116 	return __UNCONST(s);
117 }
118