add ftok example

README.md

@@ -1,2 +1,44 @@
 # ftok
+[![PkgGoDev](https://pkg.go.dev/badge/github.com/hslam/ftok)](https://pkg.go.dev/github.com/hslam/ftok)
+[![Go Report Card](https://goreportcard.com/badge/github.com/hslam/ftok)](https://goreportcard.com/report/github.com/hslam/ftok)
+[![LICENSE](https://img.shields.io/github/license/hslam/ftok.svg?style=flat-square)](https://github.com/hslam/ftok/blob/master/LICENSE)
+
 Package ftok provides a way to generate a System V IPC key, suitable for use with msgget, semget, or shmget.
+
+## Get started
+
+### Install
+```
+go get github.com/hslam/ftok
+```
+### Import
+```
+import "github.com/hslam/ftok"
+```
+### Usage
+#### Example
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/hslam/ftok"
+)
+
+func main() {
+	key_t, err := ftok.Ftok("/tmp", 0x22)
+	if err != nil {
+		return
+	}
+	fmt.Printf("%x", key_t)
+}
+```
+
+### License
+This package is licensed under a MIT license (Copyright (c) 2020 Meng Huang)
+
+
+### Author
+ftok was written by Meng Huang.
+
+