1 files changed, 42 insertions, 0 deletions
diff --git a/luni/src/main/native/readlink.cpp b/luni/src/main/native/readlink.cpp
new file mode 100644
index 0000000..555d515
--- /dev/null
+++ b/luni/src/main/native/readlink.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "LocalArray.h"
+#include "readlink.h"
+
+#include <string>
+#include <unistd.h>
+
+bool readlink(const char* path, std::string& result) {
+    // We can't know how big a buffer readlink(2) will need, so we need to
+    // loop until it says "that fit".
+    size_t bufSize = 512;
+    while (true) {
+        LocalArray<512> buf(bufSize);
+        ssize_t len = readlink(path, &buf[0], buf.size());
+        if (len == -1) {
+            // An error occurred.
+            return false;
+        }
+        if (static_cast<size_t>(len) < buf.size()) {
+            // The buffer was big enough.
+            result.assign(&buf[0], len);
+            return true;
+        }
+        // Try again with a bigger buffer.
+        bufSize *= 2;
+    }
+}