source/texk/kpathsea/xdirname.c

   1 /* xdirname.c: return the directory part of a path.
   2
   3    Copyright 1999, 2008, 2011 Karl Berry.
   4    Copyright 2005 Olaf Weber.
   5
   6    This library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    This library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public License
  17    along with this library; if not, see <http://www.gnu.org/licenses/>.  */
  18
  19 /* Return directory for NAME.  This is "." if NAME contains no directory
  20    separators (should never happen for selfdir), else whatever precedes
  21    the final directory separator, but with multiple separators stripped.
  22    For example, `xdirname ("/foo//bar.baz")' returns "/foo".  Always
  23    return a new string.  */
  24
  25 #include <kpathsea/config.h>
  26 #include <kpathsea/c-pathch.h>
  27
  28 string
  29 xdirname (const_string name)
  30 {
  31     string ret;
  32     unsigned limit = 0, loc;
  33 #if defined(WIN32)
  34     string p;
  35     unsigned i, j;
  36 #endif
  37
  38     /* Ignore a NULL name. */
  39     if (!name)
  40         return NULL;
  41
  42     if (NAME_BEGINS_WITH_DEVICE(name)) {
  43         limit = 2;
  44     } else if (IS_UNC_NAME(name)) {
  45         for (limit = 2; name[limit] && !IS_DIR_SEP (name[limit]); limit++)
  46 #if defined(WIN32)
  47             if (IS_KANJI(name+limit)) limit++
  48 #endif
  49             ;
  50         if (name[limit++] && name[limit] && !IS_DIR_SEP (name[limit])) {
  51             for (; name[limit] && !IS_DIR_SEP (name[limit]); limit++)
  52 #if defined(WIN32)
  53                 if (IS_KANJI(name+limit)) limit++
  54 #endif
  55                 ;
  56             limit--;
  57         } else
  58             /* malformed UNC name, backup */
  59             limit = 0;
  60     }
  61
  62 #if defined(WIN32)
  63     j = loc = limit;
  64     if (j > 2) j++;
  65     for (i = j; name[i]; i++) {
  66         if (IS_DIR_SEP (name[i])) {
  67             j = i;
  68             for (i++; IS_DIR_SEP (name[i]); i++)
  69                 ;
  70             loc = i + 1;
  71         } else if (IS_KANJI(name+i)) i++;
  72     }
  73 #else
  74     for (loc = strlen (name); loc > limit && !IS_DIR_SEP (name[loc-1]); loc--)
  75         ;
  76 #endif
  77
  78     if (loc == limit) {
  79         if (limit == 0)
  80             ret = xstrdup (".");
  81         else if (limit == 2) {
  82             ret = (string)xmalloc(4);
  83             ret[0] = name[0];
  84             ret[1] = name[1];
  85             ret[2] = '.';
  86             ret[3] = '\0';
  87         } else {
  88             /* UNC name is "//server/share".  */
  89             ret = xstrdup (name);
  90         }
  91     } else {
  92         /* If have ///a, must return /, so don't strip off everything.  */
  93 #if defined(WIN32)
  94         loc = j;
  95         if (loc == limit && IS_DIR_SEP (name[loc])) loc++;
  96 #else
  97         while (loc > limit+1 && IS_DIR_SEP (name[loc-1])) {
  98             loc--;
  99         }
 100 #endif
 101         ret = (string)xmalloc(loc+1);
 102         strncpy(ret, name, loc);
 103         ret[loc] = '\0';
 104     }
 105
 106 #if defined(WIN32)
 107     for (p = ret; *p; p++) {
 108         if (*p == '\\')
 109             *p = '/';
 110         else if (IS_KANJI(p))
 111             p++;
 112     }
 113 #endif
 114
 115     return ret;
 116 }