lib/libc/nls/catgets.c

   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 }