I downloaded a .deb Debian file. How do I extract deb package without installing it on my Debian or Ubuntu Linux based system? How do I list and extract the contents of a Debian package?

A Debian or Ubuntu .deb package is nothing but old good Unix ar archive format. The ar command is used to keep together groups of files as a single archive and .deb includes the following three files:

• debian-binary – A text file indicating the version of the .deb package format.
• control.tar.gz – A compressed file and it contains md5sums and control directory for building package.
• data.tar.xz – A compressed file and it contains all the files to be installed on your system.

Let us see how to list and extract the contents of a .deb package file on Debian/Mint/Ubuntu Linux using various command line options.

Related: How To: Extract an RPM Package Files Without Installing It On RHEL/CentOS/Fedora Linux

Step 1 – Download .deb package

Use the apt-get command/apt command as follows to download a file named nginx*.deb:
$ apt download nginx
OR
$ aptitude download nginx
OR
$ apt-get download nginx
Sample outputs:

Get:1 http://in.archive.ubuntu.com/ubuntu xenial-updates/main amd64 nginx all 1.10.0-0ubuntu0.16.04.4 [3,498 B]
Fetched 3,498 B in 0s (4,460 B/s)

To list file use the ls command:
$ ls *.deb
nginx_1.10.0-0ubuntu0.16.04.4_all.deb

Step 2 – Extract .deb package using ar command

The syntax is:
ar x {file.deb}

Install ar command

You can install ar command using the following apt-get command/apt command:
$ sudo apt install binutils
OR
$ sudo apt-get install binutils
Sample outputs:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Suggested packages:
  binutils-doc
The following NEW packages will be installed:
  binutils
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 2,310 kB of archives.
After this operation, 13.6 MB of additional disk space will be used.
Get:1 http://in.archive.ubuntu.com/ubuntu xenial-updates/main amd64 binutils amd64 2.26.1-1ubuntu1~16.04.3 [2,310 kB]
Fetched 2,310 kB in 6s (343 kB/s)                                                                                                                                           
Selecting previously unselected package binutils.
(Reading database ... 92869 files and directories currently installed.)
Preparing to unpack .../binutils_2.26.1-1ubuntu1~16.04.3_amd64.deb ...
Unpacking binutils (2.26.1-1ubuntu1~16.04.3) ...
Processing triggers for libc-bin (2.23-0ubuntu5) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up binutils (2.26.1-1ubuntu1~16.04.3) ...
Processing triggers for libc-bin (2.23-0ubuntu5) ...

To extract nginx_1.10.0-0ubuntu0.16.04.4_all.deb, run:
$ ar vx nginx_1.10.0-0ubuntu0.16.04.4_all.deb
$ ls -l
Sample outputs:

Extract files from control.tar.gz and data.tar.gz

Type the following tar command:
$ tar xvf control.tar.gz
$ tar data.tar.gz
$ ls -l
All files are extracted into the current directory.

Say hello to dpkg-deb command

You can use the dpkg-deb command to extract .deb file too. The syntax is:
$ dpkg-deb -xv {file.deb} {/path/to/where/extract}
To extract htop_2.0.1-1ubuntu1_amd64.deb in the /tmp/ directory run:
$ dpkg-deb -xv htop_2.0.1-1ubuntu1_amd64.deb /tmp/
To extract htop_2.0.1-1ubuntu1_amd64.deb in the current directory run:
$ dpkg-deb -xv htop_2.0.1-1ubuntu1_amd64.deb .
Sample session:

How do I view contents of a Debian package without extracting it?

The syntax is:
$ dpkg -c {file.deb}
OR
$ apt-file list {packageName}
For example to view contents of a Debian package named htop_2.0.1-1ubuntu1_amd64.deb, run:
$ dpkg -c htop_2.0.1-1ubuntu1_amd64.deb
Sample outputs:

You can also use apt-file command as follows

The apt-file is not installed by default. So install it and use it as follows:
$ sudo apt-get install apt-file ## install ##
$ sudo apt-file update ## update package cache ##
$ apt-file list htop ## list htop package contents ##
Sample outputs: