github.com/mdempsky/go@v0.0.0-20151201204031-5dd372bd1e70/src/archive/zip/example_test.go (about)

     1  // Copyright 2012 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package zip_test
     6  
     7  import (
     8  	"archive/zip"
     9  	"bytes"
    10  	"compress/flate"
    11  	"fmt"
    12  	"io"
    13  	"log"
    14  	"os"
    15  )
    16  
    17  func ExampleWriter() {
    18  	// Create a buffer to write our archive to.
    19  	buf := new(bytes.Buffer)
    20  
    21  	// Create a new zip archive.
    22  	w := zip.NewWriter(buf)
    23  
    24  	// Add some files to the archive.
    25  	var files = []struct {
    26  		Name, Body string
    27  	}{
    28  		{"readme.txt", "This archive contains some text files."},
    29  		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
    30  		{"todo.txt", "Get animal handling licence.\nWrite more examples."},
    31  	}
    32  	for _, file := range files {
    33  		f, err := w.Create(file.Name)
    34  		if err != nil {
    35  			log.Fatal(err)
    36  		}
    37  		_, err = f.Write([]byte(file.Body))
    38  		if err != nil {
    39  			log.Fatal(err)
    40  		}
    41  	}
    42  
    43  	// Make sure to check the error on Close.
    44  	err := w.Close()
    45  	if err != nil {
    46  		log.Fatal(err)
    47  	}
    48  }
    49  
    50  func ExampleReader() {
    51  	// Open a zip archive for reading.
    52  	r, err := zip.OpenReader("testdata/readme.zip")
    53  	if err != nil {
    54  		log.Fatal(err)
    55  	}
    56  	defer r.Close()
    57  
    58  	// Iterate through the files in the archive,
    59  	// printing some of their contents.
    60  	for _, f := range r.File {
    61  		fmt.Printf("Contents of %s:\n", f.Name)
    62  		rc, err := f.Open()
    63  		if err != nil {
    64  			log.Fatal(err)
    65  		}
    66  		_, err = io.CopyN(os.Stdout, rc, 68)
    67  		if err != nil {
    68  			log.Fatal(err)
    69  		}
    70  		rc.Close()
    71  		fmt.Println()
    72  	}
    73  	// Output:
    74  	// Contents of README:
    75  	// This is the source code repository for the Go programming language.
    76  }
    77  
    78  func ExampleWriter_RegisterCompressor() {
    79  	// Override the default Deflate compressor with a higher compression
    80  	// level.
    81  
    82  	// Create a buffer to write our archive to.
    83  	buf := new(bytes.Buffer)
    84  
    85  	// Create a new zip archive.
    86  	w := zip.NewWriter(buf)
    87  
    88  	var fw *flate.Writer
    89  
    90  	// Register the deflator.
    91  	w.RegisterCompressor(zip.Deflate, func(out io.Writer) (io.WriteCloser, error) {
    92  		var err error
    93  		if fw == nil {
    94  			// Creating a flate compressor for every file is
    95  			// expensive, create one and reuse it.
    96  			fw, err = flate.NewWriter(out, flate.BestCompression)
    97  		} else {
    98  			fw.Reset(out)
    99  		}
   100  		return fw, err
   101  	})
   102  
   103  	// Proceed to add files to w.
   104  }