As you may already know, when we run an unavailable or unrecognized command in Linux, we will get an error message - "bash: command not found". The problem is some of us don't know which packages provides that particular command. Not anymore! Today, I've come across an useful utility called "command-not-found" that helps you by suggesting installation of packages when running an unavailable command in Linux.
For instance, let us say you want to run a command named "leafpad", which is not available in your Linux system. You are not sure which packages provides this command. This is where "command-not-found" utility comes in help.
The command-not-found utility will automatically search the official repositories, when entering an unrecognized or unavailable command. It uses a cache of existing programs and their associated packages to help users in their day-to-day command line work.
Install command-not-found Utility in Linux
The 'command-not-found' utility is available in AUR. So, you can install it using AUR helpers such as Paru or Yay.
$ paru -S command-not-found
Or,
$ yay -S command-not-found
Also, pkgfile package provides command-not-found hook. Just install pkgfile to use command-not-found utility.
$ sudo pacman -S pkgfile
Once it is installed, edit your .bashrc file:
$ vi ~/.bashrc
Add the following line at the end to enable it.
source /usr/share/doc/pkgfile/command-not-found.bash
Update the changes made using command:
$ source ~/.bashrc
On Ubuntu and its derivatives, it comes pre-installed.
Just in case if it is not installed already, you can install it as follows.
$ sudo apt update $ sudo apt install command-not-found
The system-wide cache is empty. You may want to run 'apt-file update' as root to update the cache.
After installing it, you may need to run the following commands as root to update the system-wide cache.
$ sudo update-command-not-found $ sudo apt-file update
Suggest Package Installation When Command Not Found in Linux
Now, run any unavailable command, for example leafpad:
It will suggest you which package provides this command. Here is the output from my Arch Linux system.
$ leafpad Command 'leafpad' not found, but can be installed with: sudo snap install leafpad
As you see in the above output, the "leafpad" command is provided by leafpad-0.8.18.1-5 package.
Let us try another command on Ubuntu:
$ emacs The program 'emacs' can be found in the following packages: * emacs24 * emacs24-nox * e3 * emacs23 * emacs23-lucid * emacs23-nox * emacs24-lucid * jove Try: sudo apt-get install <selected package>
This is just an example. This utility will suggest installation of packages when you run any unavailable command. Once you removed this utility, it won't suggest anything. It will simply display an output something like below.
"bash: emacs: command not found"
Hope this helps.
5 comments
Thanks, this is helpful. Seen it on a Ubuntu distro and wanted to add it to my debian.
Why wouldn’t you just enforce public key encryption in SSH and turn off passwords?
No need to bother with fail2ban when brute-forcing a password is literally impossible because it’s turned off.
Yes, you’re right. However, some systems or applications may require password-based authentication for certain users or scenarios. Disabling passwords entirely may not be feasible in all cases. Fail2ban provides an additional layer of security without completely eliminating the option for password authentication.
Install command-not-found with paru/yay and using apt commands? what is that kind of mixing thigs?
I’ve given the installation instructions for both Arch Linux and Ubuntu systems. You can use the appropriate commands based on your distribution.