go/src/archive/tar/example_test.go

// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package tar_test

import (
	"archive/tar"
	"bytes"
	"fmt"
	"io"
	"log"
	"os"
)

func Example() {
	// Create a buffer to write our archive to.
	buf := new(bytes.Buffer)

	// Create a new tar archive.
	tw := tar.NewWriter(buf)

	// Add some files to the archive.
	var files = []struct {
		Name, Body string
	}{
		{"readme.txt", "This archive contains some text files."},
		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
		{"todo.txt", "Get animal handling licence."},
	}
	for _, file := range files {
		hdr := &tar.Header{
			Name: file.Name,
			Size: int64(len(file.Body)),
		}
		if err := tw.WriteHeader(hdr); err != nil {
			log.Fatalln(err)
		}
		if _, err := tw.Write([]byte(file.Body)); err != nil {
			log.Fatalln(err)
		}
	}
	// Make sure to check the error on Close.
	if err := tw.Close(); err != nil {
		log.Fatalln(err)
	}

	// Open the tar archive for reading.
	r := bytes.NewReader(buf.Bytes())
	tr := tar.NewReader(r)

	// Iterate through the files in the archive.
	for {
		hdr, err := tr.Next()
		if err == io.EOF {
			// end of tar archive
			break
		}
		if err != nil {
			log.Fatalln(err)
		}
		fmt.Printf("Contents of %s:\n", hdr.Name)
		if _, err := io.Copy(os.Stdout, tr); err != nil {
			log.Fatalln(err)
		}
		fmt.Println()
	}

	// Output:
	// Contents of readme.txt:
	// This archive contains some text files.
	// Contents of gopher.txt:
	// Gopher names:
	// George
	// Geoffrey
	// Gonzo
	// Contents of todo.txt:
	// Get animal handling licence.
}