Some additions to support symlinks better on platforms that support them.

base/file_util_posix.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/file_util.h"
 
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fnmatch.h>
@@ skipping 355 matching lines @@
   while (total_read < bytes) {
     ssize_t bytes_read =
         HANDLE_EINTR(read(fd, buffer + total_read, bytes - total_read));
     if (bytes_read <= 0)
       break;
     total_read += bytes_read;
   }
   return total_read == bytes;
 }
 
+bool CreateSymbolicLink(const FilePath& target_path,
+                        const FilePath& symlink_path) {
+  DCHECK(!symlink_path.empty());
+  DCHECK(!target_path.empty());
+  return ::symlink(target_path.value().c_str(),
+                   symlink_path.value().c_str()) != -1;
+}
+
+bool ReadSymbolicLink(const FilePath& symlink_path,
+                      FilePath* target_path) {
+  DCHECK(!symlink_path.empty());
+  DCHECK(target_path);
+  char buf[PATH_MAX];
+  ssize_t count = ::readlink(symlink_path.value().c_str(), buf, arraysize(buf));
+
+  if (count <= 0)
+    return false;
+
+  *target_path = FilePath(FilePath::StringType(buf, count));
+
+  return true;
+}
+
 // Creates and opens a temporary file in |directory|, returning the
 // file descriptor. |path| is set to the temporary file path.
 // This function does NOT unlink() the file.
 int CreateAndOpenFdForTemporaryFile(FilePath directory, FilePath* path) {
   base::ThreadRestrictions::AssertIOAllowed();  // For call to mkstemp().
   *path = directory.Append(kTempFileName);
   const std::string& tmpdir_string = path->value();
   // this should be OK since mkstemp just replaces characters in place
   char* buffer = const_cast<char*>(tmpdir_string.c_str());
 
@@ skipping 471 matching lines @@
   if (HANDLE_EINTR(close(infile)) < 0)
     result = false;
   if (HANDLE_EINTR(close(outfile)) < 0)
     result = false;
 
   return result;
 }
 #endif  // defined(OS_MACOSX)
 
 }  // namespace file_util