1  /* Test the access rights of a file.
       2     Copyright (C) 2019-2023 Free Software Foundation, Inc.
       3  
       4     This file is free software: you can redistribute it and/or modify
       5     it under the terms of the GNU Lesser General Public License as
       6     published by the Free Software Foundation; either version 2.1 of the
       7     License, or (at your option) any later version.
       8  
       9     This file is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public License
      15     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  #include <config.h>
      18  
      19  /* Specification.  */
      20  #include <unistd.h>
      21  
      22  #include <errno.h>
      23  #include <fcntl.h>
      24  #include <string.h>
      25  #include <sys/types.h>
      26  #include <sys/stat.h>
      27  
      28  #if defined _WIN32 && !defined __CYGWIN__
      29  # include <io.h>
      30  #endif
      31  
      32  int
      33  access (const char *file, int mode)
      34  #undef access
      35  {
      36    int ret;
      37  
      38  #if defined _WIN32 && !defined __CYGWIN__
      39    if ((mode & X_OK) != 0)
      40      mode = (mode & ~X_OK) | R_OK;
      41    ret = _access (file, mode);
      42  #else
      43    ret = access (file, mode);
      44  #endif
      45  
      46  #if (defined _WIN32 && !defined __CYGWIN__) || ACCESS_TRAILING_SLASH_BUG
      47  # if defined _WIN32 && !defined __CYGWIN__
      48    if (ret == 0 || errno == EINVAL)
      49  # else
      50    if (ret == 0)
      51  # endif
      52      {
      53        size_t file_len = strlen (file);
      54        if (file_len > 0 && file[file_len - 1] == '/')
      55          {
      56            struct stat st;
      57            if (stat (file, &st) == 0)
      58              {
      59                if (! S_ISDIR (st.st_mode))
      60                  {
      61                    errno = ENOTDIR;
      62                    return -1;
      63                  }
      64              }
      65            else
      66              return (mode == F_OK && errno == EOVERFLOW ? 0 : -1);
      67          }
      68      }
      69  #endif
      70    return ret;
      71  }