Archiving and compression on GNU/Linux

This note was created on 2020-04-07
This note was last edited on 2023-02-01

The traditional Unix archiving and compression tools are separated according to the Unix philosophy (https://en.wikipedia.org/wiki/Unix_philosophy):
- A file archiver combines several files into one archive file, e.g. "tar".
- A compression tool compresses and decompresses data, e.g. "gzip".
These tools are often used in sequence by firstly creating an archive file and then compressing it.
Of course there are also tools that do both, which tend to additionally offer encryption, error detection and recovery. 

=== tar ===
"tar" is a utility for collecting many files into one archive file, often referred to as a tarball. "tar" also can work with a lot of compessions. Here's how to use it:

Create "archive.tar" from files "file1" and "file2":
$ tar -cf archive.tar file1 file2

Extract all files form "archive.tar":
$ tar -xf archive.tar

Extract all files form "archive.tar" to specific directory:
$ tar -xf archive.tar -C /home/$USER/Documents

Extract all ".jpg" files form "archive.tar" using wildcards:
$ tar -xf archive.tar --wildcards "*.jpg"

List all files in "archive.tar": 
$ tar -tf archive.tar

Add file(s) to existing archive:
$ tar -rf archive.tar file3

Extract specific file: 
$ tar -xf archive.tar file1

Create compressed archive "archive.tar.gz":
$ tar -czf archive.tar.gz file1 file2

Extract all files from compressed archive "archive.tar.gz":
$ tar -xzf archive.tar.gz

View all options:
$ man tar

Additional options:
- "-v" - verbose output.
- "-O" - write to stdout.
- "-j" or "--bzip2" - filter the archive through bzip2.
- "-J" or "--xz" - filter the archive through xz.
- "--lzip" - filter the archive through lzip.
- "--lzma" - filter the archive through lzma.
- "--lzop" - filter the archive through lzop.
- "-z" or "--gzip" - filter the archive through gzip.
- "--zstd" - filter the archive through zstd.

=== gzip ===
The "gzip" command is a common way of compressing files within Linux. Here's how to use it:

Compress a file: 
$ gzip file

Compress a file, while specifying the compression level (1 being worst, 9 best, and 6 default). For example, level 7: 
$ gzip -7 file

Decompress a file: 
$ gzip -d file.gz

List compressed file contents:
$ gzip -l file.gz

View all options:
$ man gzip

Additional options:
- "-v" - verbose output.
- "-с" - write to stdout.
- "-k" - keep source file.
- "-f" - force overwrite of output file and compress links.
- "-t" - test compressed file integrity.

=== lz4 ===
LZ4 is a lossless data compression algorithm that is focused on compression and decompression speed. Here's how to use "lz4" compression tool:

Compress a file:
$ lz4 file

Compress a file, while specifying the compression level (1 being worst, 9 best, and 3 default). For example, level 7: 
$ lz4 -7 file

Decompress a file:
$ lz4 -d file.gz

View all options:
$ man lz4

Additional options:
- "-v" - verbose output.
- "-с" - write to stdout.
- "--rm" - remove source file.
- "-f" - force overwrite of output file.
- "-t" - test compressed file integrity.

=== xz ===
"xz" is a general-purpose data compression tool. Here's how to use it:

Compress a file: 
$ xz file

Compress a file, while specifying the compression level (0 being worst, 9 best, and 6 default). For example, level 7: 
$ xz -7 file

Decompress a file:
$ xz -d file.gz

List compressed file contents:
$ xz -l file.gz

View all options:
$ man xz

Additional options:
- "-v" - verbose output.
- "-с" - write to stdout.
- "-k" - keep source file.
- "-f" - force overwrite of output file.
- "-t" - test compressed file integrity.

=== bzip2 ===
bzip2 is a file compression program that uses the Burrows–Wheeler algorithm. Here's how to use it:

Compress a file:
$ bzip2 file

Compress a file, while specifying the compression level (1 being worst, 9 best, and 9 default). For example, level 7: 
$ bzip2 -7 file

Decompress a file: 
$ bzip2 -d file.gz

View all options:
$ man bzip2

Additional options:
- "-v" - verbose output.
- "-с" - write to stdout.
- "-k" - keep source file.
- "-f" - force overwrite of output file.
- "-t" - test compressed file integrity.

=== zstd ===
You can read about ZStandard on my site here: www.pashynskykh.com/notes/zstd.txt

=== zip/unzip ===
You can read about zip and unzip tools on my site here: www.pashynskykh.com/notes/zip.txt

=== rar/unrar ===
You can read about rar and unrar tools on my site here: www.pashynskykh.com/notes/rar.txt