lib/suitar/example_test.go

// Copyright 2026 The Wuffs Authors.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//
// SPDX-License-Identifier: Apache-2.0 OR MIT

package suitar_test

import (
	"bytes"
	"fmt"
	"io"
	"log"
	"os"
	"time"

	"github.com/google/wuffs/lib/suitar"
)

func Example_minimal() {
	// This mimics Example_minimal from the standard library's archive/tar.
	//
	// This package's Writer is a little more strict, rejecting an (implicit)
	// zero-valued Header.Typeflag or Header.ModTime that archive/tar accepts.
	// Header.Mode must also be 0o644 (or 0o755), not 0o600.

	// Create and add some files to the archive.
	var buf bytes.Buffer
	tw := suitar.NewWriter(&buf)
	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 license."},
	}
	for _, file := range files {
		hdr := &suitar.Header{
			Typeflag: suitar.TypeReg,
			Name:     file.Name,
			Size:     int64(len(file.Body)),
			Mode:     suitar.Mode644,
			ModTime:  time.Unix(0, 0),
		}
		if err := tw.WriteHeader(hdr); err != nil {
			log.Fatal(err)
		}
		if _, err := tw.Write([]byte(file.Body)); err != nil {
			log.Fatal(err)
		}
	}
	if err := tw.Close(); err != nil {
		log.Fatal(err)
	}

	// Open and iterate through the files in the archive.
	tr := suitar.NewReader(&buf)
	for {
		hdr, err := tr.Next()
		if err == io.EOF {
			break // End of archive
		}
		if err != nil {
			log.Fatal(err)
		}
		fmt.Printf("Contents of %s:\n", hdr.Name)
		if _, err := io.Copy(os.Stdout, tr); err != nil {
			log.Fatal(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 license.
}