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Script to prevent accidental execution of critical commands, e.g. to shutdown or reboot the system by prompting the user to enter its hostname.

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Even though, you should always be concentrated when working on the shell of a server and think before you type, careless mistakes can happen, especially under pressure of time. For example, accidently shutting down a virtualization server can (or will) lead to extensive consequences.

One solution is to create Bash aliases to prevent the execution of critical commands such as shutdown, poweroff, halt and reboot.

However, the problem with these aliases is that you may get used to typing them and also execute them on the wrong system.

So, to avoid this, Inhibit will prompt to enter the hostname of the system you are on in order to execute the given command to shutdown, reboot or whatever.

This also applies to services controlled by systemctl. You can use Inhibit to force the confirmation for starting, stopping, restarting and reloading services.

However, checking the status of a service (using systemctl status) does not require any confirmation as this is harmless.

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Now, to e.g. prevent the accidental execution of the shutdown, poweroff, halt and reboot commands, add the following lines either to /etc/bashrc (system wide) or ~/.bashrc (for the current user, only).

In the following examples inhibit.sh is located in /opt/inhibit.

# Prevent certain commands to shutdown the system in any way
alias halt='/opt/inhibit/inhibit.sh halt'
alias poweroff='/opt/inhibit/inhibit.sh poweroff'
alias reboot='/opt/inhibit/inhibit.sh reboot'
alias shutdown='/opt/inhibit/inhibit.sh shutdown'

You can also give command-line arguments for the inhibited command, for example:

alias poweroff='/opt/inhibit/inhibit.sh poweroff -f'

As already mentioned above, you can also inhibit commands for services controlled by systemctl.

alias systemctl='/opt/inhibit/inhibit.sh systemctl'

Notice that this alias will have no effect unless you explicitly add the name of the service (or services) which should be confirmed to the service list inside inhibit.conf. Details can be found inside that file.

After adding the preferred aliases, you can apply the changes either by logging out and in again or by reloading the .bashrc file of the current user (depending on in which file you have added the aliases).

$ source ~/.bashrc

For example, if you add the line

alias poweroff='/opt/inhibit/inhibit.sh poweroff -f'

to your .bashrc file and reload it (e.g. manually using the source command or automatically by login) and try to execute the poweroff command, the following confirmation prompt will appear.

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 ##   ## ## ##  ########   ##   #######    ##      ##     ######    ##    ##
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####  ##    ##  ##    ##  ####  #######   ####     ##     ########  #######

Warning! The 'poweroff' command has been inhibited!

In order to proceed you have to confirm the process.

Hostname: foobar
Confirm:

So, the command will only be executed if the confirmation was successful.

The header can also be customized and there also is an interactive dialog feature.

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Any suggestions, questions, bugs to report or feedback to give?

You can contact me by sending an email to [email protected] or by opening a GitHub issue (which I would prefer if you have a GitHub account).

Further information can be found inside the CONTACT file.

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