maint: update copyright

[gnulib.git] / lib / readlink.c

diff --git a/lib/readlink.c b/lib/readlink.c
index bf8a5f7..4c49639 100644 (file)
--- a/lib/readlink.c
+++ b/lib/readlink.c
@@ -1,10 +1,10 @@
 /* Stub for readlink().
-   Copyright (C) 2003-2004 Free Software Foundation, Inc.
+   Copyright (C) 2003-2007, 2009-2014 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
@@ -12,38 +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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 <sys/types.h>
+#include <string.h>
 #include <sys/stat.h>
-#include <stddef.h>
 
 #if !HAVE_READLINK
 
 /* readlink() substitute for systems that don't have a readlink() function,
    such as DJGPP 2.03 and mingw32.  */
 
-/* The official POSIX return type of readlink() is ssize_t, but since here
-   we have no declaration in a public header file, we use 'int' as return
-   type.  */
-
-int
-readlink (const char *path, char *buf, size_t bufsize)
+ssize_t
+readlink (const char *name, char *buf _GL_UNUSED,
+          size_t bufsize _GL_UNUSED)
 {
   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
+     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 (path, &statbuf) >= 0)
+  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 */