Configuring hotkeys for the console

There are two types of hotkeys to create in Linux: console hotkeys and X hotkeys. This explains how to configure console hotkeys on a Debian Linux system.

There are three things you have to do to make a console hotkey:

1. Create a readline configuration file. If intended to be system-wide, use /etc/inputrc, but if only meant for private consumption, use ~/.inputrc.
2. Make en environment variable called INPUTRC that points to either of the files mentioned above.
3. Determine the sequence of characters that is generated by the desired key(-combination).
4. Configure the readline configuration file.

The first two steps are self-explanatory, so I'll only explain the last two below, which are not so obvious.

Depending on your terminal type, sequences of key-characters are sent to readline for interpretation. It is these key-character sequences that you want your system to react differently to. But, first you have to find out what they key-character sequence is of the key that you want to configure as a hotkey. To find that out, you use readline's quoted-insert function, which you should find bound to Ctrl-v. It works like this (at the console):

~$ [Ctrl-v] [key(-combination)]

For example, pressing Ctrl-v followed by F10 produces: ^[[21~

More is possible, but the simplest syntax for readline looks like this:

"[key-character sequence]": "[command]"

So, for example, to get Midnight Commander (mc) to start up when F10 is pressed, add the following line to the readline configuration file:

"\e[21~": "mc"

However, in this case hitting F10 would only result in 'mc' showing up on the command line; you'd still have to press Enter to get mc to actually start. To make F10 do mc [ENTER], modify the line as follows:

"\e[21~": "mc\C-M"

The Carriage Return is also known as a Control-M, which is what readline's special notation "\C-M" represents.

• Brouwer A. 2002. The Linux keyboard and console HOWTO. HTML at The Linux Documentation Project.
• Brouwer A. 2009. Keyboard scancodes. HTML at Technical University of Eindhoven.
• Henderson B. 2000. How To Make A Hotkey On The Linux Console. HTML at The Linux Gazette.