sevenzip

README

sevenzip

A reader for 7-zip archives inspired by archive/zip.

Current status:

• Pure Go, no external libraries or binaries needed.
• Handles uncompressed headers, (7za a -mhc=off test.7z ...).
• Handles compressed headers, (7za a -mhc=on test.7z ...).
• Handles password-protected versions of both of the above (7za a -mhc=on|off -mhe=on -ppassword test.7z ...).
• Handles archives split into multiple volumes, (7za a -v100m test.7z ...).
• Validates CRC values as it parses the file.
• Supports BCJ2, Brotli, Bzip2, Copy, Deflate, Delta, LZ4, LZMA, LZMA2 and Zstandard methods.
• Implements the fs.FS interface so you can treat an opened 7-zip archive like a filesystem.

More examples of 7-zip archives are needed to test all of the different combinations/algorithms possible.

Documentation

Index

• func RegisterDecompressor(method []byte, dcomp Decompressor)
• type CryptoReadCloser
• type Decompressor
• type File
  • func (f *File) IsEncrypted() bool
  • func (f *File) Open() (io.ReadCloser, error)
• type FileHeader
  • func (h *FileHeader) FileInfo() fs.FileInfo
  • func (h *FileHeader) Mode() (mode fs.FileMode)
• type ReadCloser
  • func OpenReader(name string) (*ReadCloser, error)
  • func OpenReaderWithPassword(name, password string) (*ReadCloser, error)
  • func (rc *ReadCloser) Close() error
  • func (rc *ReadCloser) Volumes() []string
• type Reader
  • func NewReader(r io.ReaderAt, size int64) (*Reader, error)
  • func NewReaderWithPassword(r io.ReaderAt, size int64, password string) (*Reader, error)
  • func (z *Reader) Open(name string) (fs.File, error)

Examples

• OpenReader

Functions

func RegisterDecompressor

func RegisterDecompressor(method []byte, dcomp Decompressor)

RegisterDecompressor allows custom decompressors for a specified method ID.

Types

type CryptoReadCloser

type CryptoReadCloser interface {
	Password(string) error
}

CryptoReadCloser adds a Password method to decompressors.

type Decompressor

type Decompressor func([]byte, uint64, []io.ReadCloser) (io.ReadCloser, error)

Decompressor describes the function signature that decompression/decryption methods must implement to return a new instance of themselves. They are passed any property bytes, the size of the stream and a slice of at least one io.ReadCloser's providing the stream(s) of bytes.

type File

type File struct {
	FileHeader
	// contains filtered or unexported fields
}

A File is a single file in a 7-Zip archive. The file information is in the embedded FileHeader. The file content can be accessed by calling Open.

func (*File) IsEncrypted

func (f *File) IsEncrypted() bool

IsEncrypted returns true if file is encrypted with AES

func (*File) Open

func (f *File) Open() (io.ReadCloser, error)

Open returns an io.ReadCloser that provides access to the File's contents. Multiple files may be read concurrently.

type FileHeader

type FileHeader struct {
	Name             string
	Created          time.Time
	Accessed         time.Time
	Modified         time.Time
	Attributes       uint32
	CRC32            uint32
	UncompressedSize uint64
	// contains filtered or unexported fields
}

FileHeader describes a file within a 7-zip file.

func (*FileHeader) FileInfo

func (h *FileHeader) FileInfo() fs.FileInfo

FileInfo returns an fs.FileInfo for the FileHeader.

func (*FileHeader) Mode

func (h *FileHeader) Mode() (mode fs.FileMode)

Mode returns the permission and mode bits for the FileHeader.

type ReadCloser

type ReadCloser struct {
	Reader
	// contains filtered or unexported fields
}

A ReadCloser is a Reader that must be closed when no longer needed.

func OpenReader

func OpenReader(name string) (*ReadCloser, error)

OpenReader will open the 7-zip file specified by name and return a ReadCloser. If name has a ".001" suffix it is assumed there are multiple volumes and each sequential volume will be opened.

Example

package main

import (
	"fmt"
	"path/filepath"

	"github.com/todylcom/sevenzip"
)

func main() {
	r, err := sevenzip.OpenReader(filepath.Join("testdata", "multi.7z.001"))
	if err != nil {
		panic(err)
	}
	defer r.Close()

	for _, file := range r.File {
		fmt.Println(file.Name)
	}
}

Output:

01
02
03
04
05
06
07
08
09
10

func OpenReaderWithPassword

func OpenReaderWithPassword(name, password string) (*ReadCloser, error)

OpenReaderWithPassword will open the 7-zip file specified by name using password as the basis of the decryption key and return a ReadCloser. If name has a ".001" suffix it is assumed there are multiple volumes and each sequential volume will be opened.

func (*ReadCloser) Close

func (rc *ReadCloser) Close() error

Close closes the 7-zip file or volumes, rendering them unusable for I/O.

func (*ReadCloser) Volumes

func (rc *ReadCloser) Volumes() []string

Volumes returns the list of volumes that have been opened as part of the current archive.

type Reader

type Reader struct {
	File []*File
	// contains filtered or unexported fields
}

A Reader serves content from a 7-Zip archive.

func NewReader

func NewReader(r io.ReaderAt, size int64) (*Reader, error)

NewReader returns a new Reader reading from r, which is assumed to have the given size in bytes.

func NewReaderWithPassword

func NewReaderWithPassword(r io.ReaderAt, size int64, password string) (*Reader, error)

NewReaderWithPassword returns a new Reader reading from r using password as the basis of the decryption key, which is assumed to have the given size in bytes.

func (*Reader) Open

func (z *Reader) Open(name string) (fs.File, error)

Open opens the named file in the 7-zip archive, using the semantics of fs.FS.Open: paths are always slash separated, with no leading / or ../ elements.