compat/realpath.c

   1 /*****************************************************************************
   2  * realpath.c: POSIX realpath replacement
   3  *****************************************************************************
   4  * Copyright © 2016 VLC authors and VideoLAN
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program 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
  14  * GNU 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 program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #include <stdlib.h>
  26 #include <errno.h>
  27 #ifdef _WIN32
  28 #include <windows.h>
  29 #endif
  30
  31 char *realpath(const char * restrict relpath, char * restrict resolved_path)
  32 {
  33     if (relpath == NULL)
  34     {
  35         errno = EINVAL;
  36         return NULL;
  37     }
  38
  39 #ifdef _WIN32
  40     int len = MultiByteToWideChar( CP_UTF8, 0, relpath, -1, NULL, 0 );
  41     if (len == 0)
  42         return NULL;
  43
  44     wchar_t *wrelpath = malloc(len * sizeof (wchar_t));
  45     if (wrelpath == NULL)
  46         return NULL;
  47
  48     MultiByteToWideChar( CP_UTF8, 0, relpath, -1, wrelpath, len );
  49
  50     wchar_t *wfullpath = _wfullpath( NULL, wrelpath, _MAX_PATH );
  51     free(wrelpath);
  52     if (wfullpath != NULL)
  53     {
  54         size_t len = WideCharToMultiByte( CP_UTF8, 0, wfullpath, -1, NULL, 0, NULL, NULL );
  55         if (len != 0)
  56         {
  57             if (resolved_path != NULL)
  58                 len = len >= _MAX_PATH ? _MAX_PATH : len;
  59             else
  60                 resolved_path = (char *)malloc(len);
  61
  62             if (resolved_path != NULL)
  63                 WideCharToMultiByte( CP_UTF8, 0, wfullpath, -1, resolved_path, len, NULL, NULL );
  64             free(wfullpath);
  65             return resolved_path;
  66         }
  67         free(wfullpath);
  68     }
  69 #else
  70     (void)resolved_path;
  71 #endif
  72     errno = EACCES;
  73     return NULL;
  74 }