X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Freadlink.c;h=1d9b3d3b078983e8a6f4019b9ccae69c7148af56;hb=fb0f15d4d3057fd142dcd3d6d86b26ba719a88c2;hp=72d0e04475de401cc67f5d2f0e3a410511c5fcca;hpb=84645eae86ddff86ca4760ca71b4852673dedd03;p=gnulib.git

diff --git a/lib/readlink.c b/lib/readlink.c
index 72d0e0447..1d9b3d3b0 100644
--- a/lib/readlink.c
+++ b/lib/readlink.c
@@ -1,10 +1,10 @@
 /* Stub for readlink().
-   Copyright (C) 2003 Free Software Foundation, Inc.
+   Copyright (C) 2003-2007, 2009-2010 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   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 2, or (at your option)
-   any later version.
+   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
@@ -12,25 +12,63 @@
    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, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
+
+/* Specification.  */
+#include <unistd.h>
 
 #include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
 
 #if !HAVE_READLINK
 
 /* readlink() substitute for systems that don't have a readlink() function,
    such as DJGPP 2.03 and mingw32.  */
 
-int
-readlink (const char *filename, char *buffer, size_t bufsize)
+ssize_t
+readlink (const char *name, char *buf _GL_UNUSED,
+          size_t bufsize _GL_UNUSED)
 {
-  errno = EINVAL;
+  struct stat statbuf;
+
+  /* In general we should use lstat() here, not stat().  But on platforms
+     without symbolic links, lstat() - if it exists - would be equivalent to
+     stat(), therefore we can use stat().  This saves us a configure check.  */
+  if (stat (name, &statbuf) >= 0)
+    errno = EINVAL;
   return -1;
 }
 
-#endif
+#else /* HAVE_READLINK */
+
+# undef readlink
+
+/* readlink() wrapper that uses correct types, for systems like cygwin
+   1.5.x where readlink returns int, and which rejects trailing slash,
+   for Solaris 9.  */
+
+ssize_t
+rpl_readlink (const char *name, char *buf, size_t bufsize)
+{
+# if READLINK_TRAILING_SLASH_BUG
+  size_t len = strlen (name);
+  if (len && name[len - 1] == '/')
+    {
+      /* Even if name without the slash is a symlink to a directory,
+         both lstat() and stat() must resolve the trailing slash to
+         the directory rather than the symlink.  We can therefore
+         safely use stat() to distinguish between EINVAL and
+         ENOTDIR/ENOENT, avoiding extra overhead of rpl_lstat().  */
+      struct stat st;
+      if (stat (name, &st) == 0)
+        errno = EINVAL;
+      return -1;
+    }
+# endif /* READLINK_TRAILING_SLASH_BUG */
+  return readlink (name, buf, bufsize);
+}
+
+#endif /* HAVE_READLINK */