Add example

README.md

@@ -40,3 +40,5 @@ progressR := &ioprogress.Reader{
 // customizable.
 io.Copy(f, progressR)
 ```
+
+See [example.go](./example.go)

example.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"time"
+
+	"github.com/mitchellh/ioprogress"
+)
+
+type FakeReader struct {
+	Length  int
+	Step    int
+	hasRead int
+}
+
+func (f *FakeReader) Read(p []byte) (int, error) {
+	if f.hasRead >= f.Length {
+		return 0, io.EOF
+	}
+	// Sleep for a while so we can see the animation.
+	<-time.After(time.Second)
+	f.hasRead += f.Step
+	return f.Step, nil
+}
+
+func (f *FakeReader) Size() int {
+	return f.Length
+}
+
+func drawDefault() {
+	r := &FakeReader{Length: 100, Step: 10}
+	progressR := &ioprogress.Reader{
+		Reader: r,
+		Size:   int64(r.Size()),
+	}
+	var buff bytes.Buffer
+	io.Copy(&buff, progressR)
+}
+
+func drawBar() {
+	r := &FakeReader{Length: 100, Step: 10}
+	bar := ioprogress.DrawTextFormatBar(20)
+	progressR := &ioprogress.Reader{
+		Reader:   r,
+		Size:     int64(r.Size()),
+		DrawFunc: ioprogress.DrawTerminalf(os.Stdout, bar),
+	}
+	var buff bytes.Buffer
+	io.Copy(&buff, progressR)
+}
+
+func drawBytes() {
+	r := &FakeReader{Length: 100, Step: 10}
+	progressR := &ioprogress.Reader{
+		Reader:   r,
+		Size:     int64(r.Size()),
+		DrawFunc: ioprogress.DrawTerminalf(os.Stdout, ioprogress.DrawTextFormatBytes),
+	}
+	var buff bytes.Buffer
+	io.Copy(&buff, progressR)
+}
+
+func main() {
+	fmt.Println("default draw...")
+	drawDefault()
+	fmt.Println("draw bar...")
+	drawBar()
+	fmt.Println("draw bytes...")
+	drawBytes()
+}