stat: new module, for mingw bug

[gnulib.git] / lib / stat.c

diff --git a/lib/stat.c b/lib/stat.c
new file mode 100644 (file)
index 0000000..c3400d5
--- /dev/null
+++ b/lib/stat.c
@@ -0,0 +1,78 @@
+/* Work around platform bugs in stat.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* written by Eric Blake */
+
+#include <config.h>
+
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <string.h>
+
+#undef stat
+
+/* For now, mingw is the only known platform where stat(".") and
+   stat("./") give different results.  Mingw stat has other bugs (such
+   as st_ino always being 0 on success) which this wrapper does not
+   work around.  But at least this implementation provides the ability
+   to emulate fchdir correctly.  */
+
+int
+rpl_stat (char const *name, struct stat *st)
+{
+  int result = stat (name, st);
+  if (result == -1 && errno == ENOENT)
+    {
+      /* Due to mingw's oddities, there are some directories (like
+         c:\) where stat() only succeeds with a trailing slash, and
+         other directories (like c:\windows) where stat() only
+         succeeds without a trailing slash.  But we want the two to be
+         synonymous, since chdir() manages either style.  Likewise, Mingw also
+         reports ENOENT for names longer than PATH_MAX, when we want
+         ENAMETOOLONG, and for stat("file/"), when we want ENOTDIR.
+         Fortunately, mingw PATH_MAX is small enough for stack
+         allocation.  */
+      char fixed_name[PATH_MAX + 1] = {0};
+      size_t len = strlen (name);
+      bool check_dir = false;
+      if (PATH_MAX <= len)
+        errno = ENAMETOOLONG;
+      else if (len)
+        {
+          strcpy (fixed_name, name);
+          if (ISSLASH (fixed_name[len - 1]))
+            {
+              check_dir = true;
+              while (len && ISSLASH (fixed_name[len - 1]))
+                fixed_name[--len] = '\0';
+              if (!len)
+                fixed_name[0] = '/';
+            }
+          else
+            fixed_name[len++] = '/';
+          result = stat (fixed_name, st);
+          if (result == 0 && check_dir && !S_ISDIR (st->st_mode))
+            {
+              result = -1;
+              errno = ENOTDIR;
+            }
+        }
+    }
+  return result;
+}