Bash – the general format of keyname for key bindings in “inputrc” file

bashreadline

I understand that the format for key bindings in inputrc file is:

keyname: function-name or macro

For keyname, I saw things like:

"\e[B"
"\e[1~"
"\e[5D"
"\M-l"
"\C-[OD"
"\e\e[D"

What is the meaning of these keynames, and what is the general format for keyname ? Please share a link to docs.

Best Answer

Keybinding can be done using one of the following forms:

keyname: command_name
"keystroke_sequence": command_name

In first form you can spell out the name for a single key. For example, CONTROL-U would be written as control-u. This is useful for binding commands to single keys.

In the second form, you specify a string that describes a sequence of keys that will be bound to the command. The one you gave as an example is the emacs-tyle backslash escape sequences to represent the special keys

\C - Control
\M - Meta
\e - Escape

You can specify a backslash using another backslash – \\. Similarly ' and " can be escaped too - \' and \"

Update

These characters is what is interpreted by your terminal when you press special keys. You don't want to bind regular alphabets and numerics in your key binding as you might be using them on regular basis and can cause issues when you accidentally hit a combination that has been mapped in your ~/.inputrc or /etc/inputrc file.

[1~ is what is interpreted by your terminal when you press your HOME button.

To learn more, simply type read on your terminal prompt and press all types of special keys like Function Keys, HOME, END, Arrow Keys etc and see what gets displayed.

Here is a small reference I found that can offer some basic understanding. Good luck! :)

Related Solutions

Bash – bash’s meta key

The mapping from keyboard keys to modifiers like Meta and Control is handled by the X server (i.e. the low-level part of the GUI). This mapping can be manipulated through the old-style xmodmap command or the new-style XKB interface, or through a GUI configuration tools that uses one of these under the hood.

By default, on most setups, the Meta key is the key labeled Alt. This is because historically, many unix workstations had a key labeled Meta where PCs have a key labeled Alt. So if you have a binding for M-C-y, press Ctrl+Alt+Y.

To check what your current bindings are, start the xev program in a terminal. With the xev window focused, press keys; you'll see a transcript of the generated events in the terminal.

The communication between terminal emulators (or terminal devices corresponding to a physical terminals) and applications uses characters. When you press A, the terminal receives the information “A key, no modifier”, but what it sends to the application running in the terminal is the character a. When you press a function key like Up or F1, there's no corresponding character; the terminal sends a character sequence beginning with the escape character (byte 27, sometimes written \e or ^[). When a terminal emulator such as xterm received a key press event with the Meta modifier, it translates that key to an escape character followed by the key's underlying function, e.g. \ea (escape, lowercase a) when you press Meta+A.

What is the exact difference between a 'terminal', a 'shell', a 'tty' and a 'console'? may be useful background.

Bash – When the lines of a file or directory get too long, upgrade to ls list format

There's no builtin option in ls that does what you want. You'd have to parse the output then restart if "long" filenames are found, or do something like:

$ ls ??????????* >& /dev/null && ls -l || ls

(Put as many ? as your length limit. You can set that up as an alias.)

Why don't you simply use ls -1? (That's a one, not a lowercase L.) It always lists files in a single column. (Or pipe ls to more or less, which also goes to single column display.) Or use find with -maxdepth 1.

Best Answer

Related Solutions

Bash – bash’s meta key

Bash – When the lines of a file or directory get too long, upgrade to ls list format

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