lib/stat.c

   1 /* Work around platform bugs in stat.
   2    Copyright (C) 2009-2011 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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 General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* written by Eric Blake */
  18
  19 #include <config.h>
  20
  21 /* Get the original definition of stat.  It might be defined as a macro.  */
  22 #define __need_system_sys_stat_h
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #undef __need_system_sys_stat_h
  26
  27 static inline int
  28 orig_stat (const char *filename, struct stat *buf)
  29 {
  30   return stat (filename, buf);
  31 }
  32
  33 /* Specification.  */
  34 #include <sys/stat.h>
  35
  36 #include <errno.h>
  37 #include <limits.h>
  38 #include <stdbool.h>
  39 #include <string.h>
  40 #include "dosname.h"
  41
  42 /* Store information about NAME into ST.  Work around bugs with
  43    trailing slashes.  Mingw has other bugs (such as st_ino always
  44    being 0 on success) which this wrapper does not work around.  But
  45    at least this implementation provides the ability to emulate fchdir
  46    correctly.  */
  47
  48 int
  49 rpl_stat (char const *name, struct stat *st)
  50 {
  51   int result = orig_stat (name, st);
  52 #if REPLACE_FUNC_STAT_FILE
  53   /* Solaris 9 mistakenly succeeds when given a non-directory with a
  54      trailing slash.  */
  55   if (result == 0 && !S_ISDIR (st->st_mode))
  56     {
  57       size_t len = strlen (name);
  58       if (ISSLASH (name[len - 1]))
  59         {
  60           errno = ENOTDIR;
  61           return -1;
  62         }
  63     }
  64 #endif /* REPLACE_FUNC_STAT_FILE */
  65 #if REPLACE_FUNC_STAT_DIR
  66   if (result == -1 && errno == ENOENT)
  67     {
  68       /* Due to mingw's oddities, there are some directories (like
  69          c:\) where stat() only succeeds with a trailing slash, and
  70          other directories (like c:\windows) where stat() only
  71          succeeds without a trailing slash.  But we want the two to be
  72          synonymous, since chdir() manages either style.  Likewise, Mingw also
  73          reports ENOENT for names longer than PATH_MAX, when we want
  74          ENAMETOOLONG, and for stat("file/"), when we want ENOTDIR.
  75          Fortunately, mingw PATH_MAX is small enough for stack
  76          allocation.  */
  77       char fixed_name[PATH_MAX + 1] = {0};
  78       size_t len = strlen (name);
  79       bool check_dir = false;
  80       if (PATH_MAX <= len)
  81         errno = ENAMETOOLONG;
  82       else if (len)
  83         {
  84           strcpy (fixed_name, name);
  85           if (ISSLASH (fixed_name[len - 1]))
  86             {
  87               check_dir = true;
  88               while (len && ISSLASH (fixed_name[len - 1]))
  89                 fixed_name[--len] = '\0';
  90               if (!len)
  91                 fixed_name[0] = '/';
  92             }
  93           else
  94             fixed_name[len++] = '/';
  95           result = orig_stat (fixed_name, st);
  96           if (result == 0 && check_dir && !S_ISDIR (st->st_mode))
  97             {
  98               result = -1;
  99               errno = ENOTDIR;
 100             }
 101         }
 102     }
 103 #endif /* REPLACE_FUNC_STAT_DIR */
 104   return result;
 105 }