How To Extract XZ Files

I've come across XZ files more than once, most recently when downloading Kali Linux. It should be a fairly common knowledge now, but some operating systems still don't support is – so I decided to research and to document it.

What is XZ file?

XZ is a modern lossless compression algorithm, it's more efficient that gzip and bzip2. Apparently, many Linux distros are using XZ for compressing their software packages or ISO images. XZ is an open-source format maintained via Tukaani Project – XZ.

Support for XZ in tar

Modern Linux distros (certainly Ubuntu 19.x and CentOS 7.x when I checked today) have xz utils package installed, which allows tar command to automatically unpack XZ files.

If xz-utils didn't come preinstalled, you can install it like this in Ubuntu/Debian:

# apt install xz-utils

or like this in CentOS/Fedora/RedHat:

# yum install xz

gzip/gunzip Support for XZ in macOS

Although tar in macOS doesn't support XZ format natively:

greys@mcfly:~/Downloads $ tar xzvf kali-linux-2020.1-rpi3-nexmon-64.img.xz
 tar: Error opening archive: Unrecognized archive format

… you can still use gunzip to decompress the XZ file in macOS:

greys@mcfly:~/Downloads $ ls -al kali-linux-2020*
-rw-r--r--@ 1 greys  staff      259647 30 Jan 22:57 kali-linux-2020-1.png
-rw-r--r--@ 1 greys  staff  1048328860 30 Jan 23:06 kali-linux-2020.1-rpi3-nexmon-64.img.xz
greys@mcfly:~/Downloads $ gunzip kali-linux-2020.1-rpi3-nexmon-64.img.xz
greys@mcfly:~/Downloads $ ls -ald kali-linux-2020.1-rpi3-nexmon-64.img
-rw-r--r--  1 greys  staff  6999999488 30 Jan 23:06 kali-linux-2020.1-rpi3-nexmon-64.img

xz-utils in macOS

If you insist on managing XZ files using xz utils, you'll need to install them with brew:

… and then a whole bunch of XZ commands becomes available:

xz
xzcat
xzcmp
xzdec
xzdiff
xzegrep
xzfgrep
xzgrep
xzless
xzmore

See Also

• XZ utils website
• 7zip in Ubuntu
• How To Use 7zip