Package tar implements access to tar archives. It aims to cover most of the variations, including those produced by GNU and BSD tars.
References:
http://www.freebsd.org/cgi/man.cgi?query=tar&sektion=5 http://www.gnu.org/software/tar/manual/html_node/Standard.html http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html
package main
import (
"archive/tar"
"bytes"
"fmt"
"io"
"log"
"os"
)
func main() {
// 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 license."},
}
for _, file := range files {
hdr := &tar.Header{
Name: file.Name,
Mode: 0600,
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()
}
}
common.go format.go reader.go stat_atim.go stat_unix.go strconv.go writer.go
Header type flags.
const (
TypeReg = '0' // regular file
TypeRegA = '\x00' // regular file
TypeLink = '1' // hard link
TypeSymlink = '2' // symbolic link
TypeChar = '3' // character device node
TypeBlock = '4' // block device node
TypeDir = '5' // directory
TypeFifo = '6' // fifo node
TypeCont = '7' // reserved
TypeXHeader = 'x' // extended header
TypeXGlobalHeader = 'g' // global extended header
TypeGNULongName = 'L' // Next file has a long name
TypeGNULongLink = 'K' // Next file symlinks to a file w/ a long name
TypeGNUSparse = 'S' // sparse file
) var (
ErrWriteTooLong = errors.New("archive/tar: write too long")
ErrFieldTooLong = errors.New("archive/tar: header field too long")
ErrWriteAfterClose = errors.New("archive/tar: write after close")
) var (
ErrHeader = errors.New("archive/tar: invalid tar header")
) A Header represents a single header in a tar archive. Some fields may not be populated.
type Header struct {
Name string // name of header file entry
Mode int64 // permission and mode bits
Uid int // user id of owner
Gid int // group id of owner
Size int64 // length in bytes
ModTime time.Time // modified time
Typeflag byte // type of header entry
Linkname string // target name of link
Uname string // user name of owner
Gname string // group name of owner
Devmajor int64 // major number of character or block device
Devminor int64 // minor number of character or block device
AccessTime time.Time // access time
ChangeTime time.Time // status change time
Xattrs map[string]string
} func FileInfoHeader(fi os.FileInfo, link string) (*Header, error)
FileInfoHeader creates a partially-populated Header from fi. If fi describes a symlink, FileInfoHeader records link as the link target. If fi describes a directory, a slash is appended to the name. Because os.FileInfo's Name method returns only the base name of the file it describes, it may be necessary to modify the Name field of the returned header to provide the full path name of the file.
func (h *Header) FileInfo() os.FileInfo
FileInfo returns an os.FileInfo for the Header.
A Reader provides sequential access to the contents of a tar archive. A tar archive consists of a sequence of files. The Next method advances to the next file in the archive (including the first), and then it can be treated as an io.Reader to access the file's data.
type Reader struct {
// contains filtered or unexported fields
} func NewReader(r io.Reader) *Reader
NewReader creates a new Reader reading from r.
func (tr *Reader) Next() (*Header, error)
Next advances to the next entry in the tar archive.
io.EOF is returned at the end of the input.
func (tr *Reader) Read(b []byte) (int, error)
Read reads from the current entry in the tar archive. It returns 0, io.EOF when it reaches the end of that entry, until Next is called to advance to the next entry.
Calling Read on special types like TypeLink, TypeSymLink, TypeChar, TypeBlock, TypeDir, and TypeFifo returns 0, io.EOF regardless of what the Header.Size claims.
A Writer provides sequential writing of a tar archive in POSIX.1 format. A tar archive consists of a sequence of files. Call WriteHeader to begin a new file, and then call Write to supply that file's data, writing at most hdr.Size bytes in total.
type Writer struct {
// contains filtered or unexported fields
} func NewWriter(w io.Writer) *Writer
NewWriter creates a new Writer writing to w.
func (tw *Writer) Close() error
Close closes the tar archive, flushing any unwritten data to the underlying writer.
func (tw *Writer) Flush() error
Flush finishes writing the current file (optional).
func (tw *Writer) Write(b []byte) (n int, err error)
Write writes to the current entry in the tar archive. Write returns the error ErrWriteTooLong if more than hdr.Size bytes are written after WriteHeader.
func (tw *Writer) WriteHeader(hdr *Header) error
WriteHeader writes hdr and prepares to accept the file's contents. WriteHeader calls Flush if it is not the first header. Calling after a Close will return ErrWriteAfterClose.
© Google, Inc.
Licensed under the Creative Commons Attribution License 3.0.
https://golang.org/pkg/archive/tar/