archive

README

github.com/kristinjeanna/archive

Package archive is a convenience package for walking/enumerating the contents of zip files, tar files, and compressed tar files through callback functions. Supported archive types include: zip, tar, gzip-compressed tar, bzip2-compressed tar, and xz-compressed tar.

• Install
• Examples
  • List the contents of a .zip file
  • Extract the contents of a .tar.xz file
  • Determine the type of archive file
• Credits

Install

go get github.com/kristinjeanna/archive

Examples

List the contents of a .zip file

func zipCallback(file *zip.File) error {
    if file.FileInfo().IsDir() {
        fmt.Printf("Dir : %s\n", file.Name)
    } else  {
        fmt.Printf("File: %s\n", file.Name)
    }

    return nil
}

func main() {
    err := archive.WalkZip("test.zip", zipCallback)
    if err != nil {
        log.Fatal(err)
    }
}

Extract the contents of a .tar.xz file

func tarCallback(reader *tar.Reader, header *tar.Header) error {
    if header.FileInfo().IsDir() {
        os.MkdirAll(header.Name, 0700)
        return nil
    }

    fo, err := os.Create(header.Name)
    if err != nil {
        return err
    }
    defer fo.Close()

    _, err := io.Copy(fo, reader)
    if err != nil {
        return err
    }

    return nil
}

func main() {
    err := archive.WalkTarXz("test.tar.xz", tarCallback)
    if err != nil {
        log.Fatal(err)
    }
}

Determine the type of archive file

func main() {
    archiveType, err := archive.DetermineType(archiveFilename)
    if err != nil {
        fmt.Fprintln(os.Stderr, "Unable to determine the file's archive type.")
        os.Exit(1)
    }

    switch archiveType {
    case archive.Tar:
        err = archive.WalkTar(archiveFilename, tarCallback)
    case archive.TarBz2:
        err = archive.WalkTarBzip2(archiveFilename, tarCallback)
    case archive.TarGz:
        err = archive.WalkTarGz(archiveFilename, tarCallback)
    case archive.TarXz:
        err = archive.WalkTarXz(archiveFilename, tarCallback)
    case archive.Zip:
        err = archive.WalkZip(archiveFilename, zipCallback)
    }

    if err != nil {
        log.Fatal(err)
    }
}

Credits

• XZ compression support via github.com/ulikunitz/xz

Documentation

Overview

Package archive is a convenience package for enumerating the contents of zip files, tar files, and compressed tar files. Supported archive types are: zip, tar, gzip-compressed tar, bzip2-compressed tar, and xz-compressed tar.

Usage

To list the contents of a zip file:

func zipCallback(file *zip.File) error {
    if file.FileInfo().IsDir() {
        fmt.Printf("Dir : %s\n", file.Name)
    } else  {
        fmt.Printf("File: %s\n", file.Name)
    }

    return nil
}

func main() {
    err := archive.WalkZip("test.zip", zipCallback)
    if err != nil {
        log.Fatal(err)
    }
}

To extract the contents of a .tar.xz file:

func tarCallback(reader *tar.Reader, header *tar.Header) error {
    if header.FileInfo().IsDir() {
        os.MkdirAll(header.Name, 0700)
        return nil
    }

    fo, err := os.Create(header.Name)
    if err != nil {
        return err
    }
    defer fo.Close()

    _, err := io.Copy(fo, reader)
    if err != nil {
        return err
    }

    return nil
}

func main() {
    err := archive.WalkTarXz("test.tar.xz", tarCallback)
    if err != nil {
        log.Fatal(err)
    }
}

To determine the type of archive file:

func main() {
    archiveType, err := archive.DetermineType(archiveFilename)
    if err != nil {
        fmt.Fprintln(os.Stderr, "Unable to determine the file's archive type.")
        os.Exit(1)
    }

    switch archiveType {
    case archive.Tar:
        err = archive.WalkTar(archiveFilename, tarCallback)
    case archive.TarBz2:
        err = archive.WalkTarBzip2(archiveFilename, tarCallback)
    case archive.TarGz:
        err = archive.WalkTarGz(archiveFilename, tarCallback)
    case archive.TarXz:
        err = archive.WalkTarXz(archiveFilename, tarCallback)
    case archive.Zip:
        err = archive.WalkZip(archiveFilename, zipCallback)
    }

    if err != nil {
        log.Fatal(err)
    }
}

Index

• func WalkTar(archivePath string, callback TarCallback) error
• func WalkTarBzip2(archivePath string, callback TarCallback) error
• func WalkTarGz(archivePath string, callback TarCallback) error
• func WalkTarXz(archivePath string, callback TarCallback) error
• func WalkZip(archivePath string, callback ZipCallback) error
• type TarCallback
• type Type
  • func DetermineType(filename string) (Type, error)
  • func (t Type) String() (result string)
• type ZipCallback

Examples

• DetermineType
• WalkTar
• WalkTarBzip2
• WalkTarGz
• WalkTarXz
• WalkZip

Functions

func WalkTar

func WalkTar(archivePath string, callback TarCallback) error

WalkTar walks the contents of a tar file and invokes the callback function for each entry.

Example

callback := func(reader *tar.Reader, header *tar.Header) error {
	fmt.Printf("%s\n", header.Name)
	return nil
}

err := WalkTar("testdata/sample.tar", callback)
if err != nil {
	log.Fatal(err)
}

Output:

sample/text/lorem.txt
sample/text/
sample/

func WalkTarBzip2

func WalkTarBzip2(archivePath string, callback TarCallback) error

WalkTarBzip2 walks the contents of a bzip2-compressed tar file and invokes the callback function for each entry.

Example

callback := func(reader *tar.Reader, header *tar.Header) error {
	fmt.Printf("%s\n", header.Name)
	return nil
}

err := WalkTarBzip2("testdata/sample.tar.bz2", callback)
if err != nil {
	log.Fatal(err)
}

Output:

sample/
sample/text/
sample/text/lorem.txt

func WalkTarGz

func WalkTarGz(archivePath string, callback TarCallback) error

WalkTarGz walks the contents of a gzip-compressed tar file and invokes the callback function for each entry.

Example

callback := func(reader *tar.Reader, header *tar.Header) error {
	fmt.Printf("%s\n", header.Name)
	return nil
}

err := WalkTarGz("testdata/sample.tar.gz", callback)
if err != nil {
	log.Fatal(err)
}

Output:

sample/
sample/text/
sample/text/lorem.txt

func WalkTarXz

func WalkTarXz(archivePath string, callback TarCallback) error

WalkTarXz walks the contents of a lzma2-compressed (xz) tar file and invokes the callback function for each entry.

Example

callback := func(reader *tar.Reader, header *tar.Header) error {
	fmt.Printf("%s\n", header.Name)
	return nil
}

err := WalkTarXz("testdata/sample.tar.xz", callback)
if err != nil {
	log.Fatal(err)
}

Output:

sample/
sample/text/
sample/text/lorem.txt

func WalkZip

func WalkZip(archivePath string, callback ZipCallback) error

WalkZip walks the contents of a zip file and invokes the callback function for each entry.

Example

callback := func(file *zip.File) error {
	fmt.Printf("%s\n", file.Name)
	return nil
}

err := WalkZip("testdata/sample.zip", callback)
if err != nil {
	log.Fatal(err)
}

Output:

sample/
sample/text/
sample/text/lorem.txt

Types

type TarCallback

type TarCallback func(*tar.Reader, *tar.Header) error

TarCallback is the type of function called for each file or directory entry visited by the WalkTar functions.

type Type

type Type uint

Type defines the archive types that can be processed in this package.

const (
	Tar Type = iota + 1
	TarBz2
	TarGz
	TarXz
	Zip
)

Valid archive types.

func DetermineType

func DetermineType(filename string) (Type, error)

DetermineType identifies the archive file type based on the extensions present in the filename. Files with the ".tar" extension will be identified as Tar. Files with ".tar.bz2", ".tar.bzip2", ".tbz", or ".tbz2" extensions will be identified as TarBz2. Files with ".tar.gz" or ".tgz" extensions will be identified as TarGz. Files with ".tar.xz" or ".txz" extensions will be identified as TarXz. Files with the ".zip" extension will be identified as Zip. Anything else returns 0 and a non-nil error.

Example

filename := "sample.tar.gz"
typ, err := DetermineType(filename)
if err != nil {
	log.Fatal(err)
}
fmt.Printf("File %s is type %s.", filename, typ)

Output:

File sample.tar.gz is type TarGz.

func (Type) String

func (t Type) String() (result string)

String returns a string representation of the archive type.

type ZipCallback

type ZipCallback func(*zip.File) error

ZipCallback is the type of function called for each file or directory entry visited by WalkZip.