lib/libc/locale/aliasname.c

   1 /* $NetBSD: src/lib/libc/locale/aliasname.c,v 1.1 2002/02/13 07:45:52 yamt Exp $ */
   2 /* $DragonFly: src/lib/libc/locale/aliasname.c,v 1.1 2005/03/16 07:54:41 joerg Exp $ */
   3
   4 /*-
   5  * Copyright (c)2002 YAMAMOTO Takashi,
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <assert.h>
  31 #include <stdio.h>
  32 #include <string.h>
  33
  34 #include "aliasname_local.h"
  35
  36 static __inline int     __is_ws(char);
  37
  38 static __inline int
  39 __is_ws(char ch)
  40 {
  41
  42         return(ch == ' ' || ch == '\t');
  43 }
  44
  45 const char *
  46 __unaliasname(const char *dbname, const char *alias, void *buf, size_t bufsize)
  47 {
  48         FILE *fp = NULL;
  49         const char *result = alias;
  50         size_t resultlen;
  51         size_t aliaslen;
  52         const char *p;
  53         size_t len;
  54
  55         _DIAGASSERT(dbname != NULL);
  56         _DIAGASSERT(alias != NULL);
  57         _DIAGASSERT(buf != NULL);
  58
  59         fp = fopen(dbname, "r");
  60         if (fp == NULL)
  61                 goto quit;
  62
  63         aliaslen = strlen(alias);
  64
  65         for (;;) {
  66                 p = fgetln(fp, &len);
  67                 if (p == NULL)
  68                         goto quit; /* eof or error */
  69
  70                 _DIAGASSERT(len != 0);
  71
  72                 /* ignore terminating NL */
  73                 if (p[len - 1] == '\n')
  74                         len--;
  75
  76                 /* ignore null line and comment */
  77                 if (len == 0 || p[0] == '#')
  78                         continue;
  79
  80                 if (aliaslen > len)
  81                         continue;
  82
  83                 if (memcmp(alias, p, aliaslen))
  84                         continue;
  85
  86                 p += aliaslen;
  87                 len -= aliaslen;
  88
  89                 if (len == 0 || !__is_ws(*p))
  90                         continue;
  91
  92                 /* entry was found here */
  93                 break;
  94
  95                 /* NOTREACHED */
  96         }
  97
  98         /* skip white spaces */
  99         do {
 100                 p++;
 101                 len--;
 102         } while (len != 0 && __is_ws(*p));
 103
 104         if (len == 0)
 105                 goto quit;
 106
 107         /* count length of result */
 108         resultlen = 0;
 109         while (resultlen < len && !__is_ws(*p))
 110                 resultlen++;
 111
 112         /* check if space is enough */
 113         if (bufsize < resultlen + 1)
 114                 goto quit;
 115
 116         memcpy(buf, p, resultlen);
 117         ((char *)buf)[resultlen] = 0;
 118         result = buf;
 119
 120 quit:
 121         if (fp)
 122                 fclose(fp);
 123
 124         return(result);
 125 }