lib/libc/nls/catgets.c

   1 /*      $NetBSD: catgets.c,v 1.19 2012/06/25 22:32:45 abs 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 1.19 2012/06/25 22:32:45 abs 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(nl_catd catd, int set_id, int msg_id, 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) -1) {
  58                 errno = EBADF;
  59                 return __UNCONST(s);
  60         }
  61
  62         cat_hdr = (struct _nls_cat_hdr *)catd->__data;
  63         set_hdr = (struct _nls_set_hdr *)(void *)((char *)catd->__data
  64                 + sizeof(struct _nls_cat_hdr));
  65
  66         /* binary search, see knuth algorithm b */
  67         l = 0;
  68         u = ntohl((u_int32_t)cat_hdr->__nsets) - 1;
  69         while (l <= u) {
  70                 i = (l + u) / 2;
  71                 r = set_id - ntohl((u_int32_t)set_hdr[i].__setno);
  72
  73                 if (r == 0) {
  74                         msg_hdr = (struct _nls_msg_hdr *)
  75                             (void *)((char *)catd->__data +
  76                             sizeof(struct _nls_cat_hdr) +
  77                             ntohl((u_int32_t)cat_hdr->__msg_hdr_offset));
  78
  79                         l = ntohl((u_int32_t)set_hdr[i].__index);
  80                         u = l + ntohl((u_int32_t)set_hdr[i].__nmsgs) - 1;
  81                         while (l <= u) {
  82                                 i = (l + u) / 2;
  83                                 r = msg_id -
  84                                     ntohl((u_int32_t)msg_hdr[i].__msgno);
  85                                 if (r == 0) {
  86                                         return ((char *) catd->__data +
  87                                             sizeof(struct _nls_cat_hdr) +
  88                                             ntohl((u_int32_t)
  89                                             cat_hdr->__msg_txt_offset) +
  90                                             ntohl((u_int32_t)
  91                                             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                         goto notfound;
 101
 102                 } else if (r < 0) {
 103                         u = i - 1;
 104                 } else {
 105                         l = i + 1;
 106                 }
 107         }
 108
 109 notfound:
 110         /* not found */
 111         errno = ENOMSG;
 112         return __UNCONST(s);
 113 }