TAR Format

Purpose

This guide covers working with Unix tape archive (TAR) files using Excavate.

References

Concepts

TAR (Tape Archive) is a Unix archive format that combines multiple files into a single archive. TAR files are often compressed with GZIP, XZ, or BZIP2.

Basic Usage

Extract Plain TAR 

Excavate::Archive.new('archive.tar').extract

Extract Compressed TAR 

# TAR + GZIP
Excavate::Archive.new('archive.tar.gz').extract
Excavate::Archive.new('archive.tgz').extract

# TAR + XZ
Excavate::Archive.new('archive.tar.xz').extract
Excavate::Archive.new('archive.txz').extract

TAR Characteristics

Characteristic Description

File extension

.tar, .tar.gz, .tgz, .tar.xz, .txz

Compression

None (plain), GZIP, XZ, BZIP2

Permissions

Preserves Unix permissions

Platform

Unix/Linux (primary)

Compound Format Support

Excavate handles compound TAR archives automatically:

TAR + GZIP 

# Automatically extracts GZIP then TAR
Excavate::Archive.new('package.tar.gz').extract

TAR + XZ 

# Automatically extracts XZ then TAR
Excavate::Archive.new('package.tar.xz').extract

Common Use Cases

Extract Source Code 

Excavate::Archive.new('project-1.0.tar.gz').extract

Extract Backup 

Excavate::Archive.new('backup.tar.gz').extract(
  filter: 'home/user/**/*'
)

Extract Specific Files 

Excavate::Archive.new('archive.tar.gz').extract(
  files: ['README.md', 'LICENSE']
)

CLI Usage 

# Extract TAR.GZ
excavate archive.tar.gz

# Extract TAR.XZ
excavate archive.tar.xz

# Extract with filter
excavate --filter "src/**/*.rb" project.tar.gz

Technical Details

Excavate uses the Omnizip gem’s TAR support:

  • Pure Ruby implementation

  • Handles various TAR formats (POSIX, GNU, PAX)

  • Preserves file permissions

  • Supports long filenames

Related Topics