From 3e1fc8333755912e73c0a1501cddcb6496e5db52 Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=82=A8=EA=B6=81=EC=84=9D/On-Device=20Lab=28SR=29/Enginee?=
 =?utf8?q?r/=EC=82=BC=EC=84=B1=EC=A0=84=EC=9E=90?= <sk.namkoong@samsung.com>
Date: Mon, 22 Apr 2019 08:26:02 +0900
Subject: [PATCH] [cwrap] Update README.md (#3324)

This commit will update README.md

Signed-off-by: Seok NamKoong <sk.namkoong@samsung.com>
---
 contrib/cwrap/README.md | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/contrib/cwrap/README.md b/contrib/cwrap/README.md
index f4f44b0..64c8084 100644
--- a/contrib/cwrap/README.md
+++ b/contrib/cwrap/README.md
@@ -1,3 +1,25 @@
-## What is "cwrap"?
+## cwrap
+
+### Purpose
 
 _cwrap_ is a collection of C++ wrappers for POSIX C API.
+
+### How to use
+
+Currently it supports only file descriptor.
+
+### Example
+- File Descriptor
+
+```cpp
+cwrap::Fildes fildes{open(path.c_str(), O_RDONLY)};
+
+if (fildes.get() < 0)
+{
+    std::ostringstream ostr;
+    ostr << "Error: " << path << " not found" << std::endl;
+    throw std::runtime_error{ostr.str()};
+}
+
+google::protobuf::io::FileInputStream fis(fildes.get());
+```
-- 
2.7.4