~/.inputrc causes CTRL+arrows not to work

bashinputrc

When ~/.inputrc does not exist, hitting Ctrl+Left Arrow and Ctrl+Right Arrow on a Bash command line moves the cursor back and forward by one word, respectively.

However, if ~/.inputrc exists (regardless of whether or not it's empty), those two key combos result in ;5D and ;5C being printed where the cursor is instead of moving the cursor.

How can I fix that?

Best Answer

Its because if the file exists, bash uses your local settings for the readline settings instead of the default one.

From http://www.gnu.org/software/bash/manual/html_node/Readline-Init-File.html

"When a program which uses the Readline library starts up, the init file is read, and the key bindings are set."

The recommendation in the sample file at gnu.org is to source the default in your local one with a line like this:

$include /etc/inputrc

and then modify from there.

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Ubuntu – Putty SSH: CTRL+Cursor keys don’t work skip to previous/next word

Add these two lines to your ~/.inputrc file on the destination machine:

"\eOD": backward-word
"\eOC": forward-word

To make sure that they are the correct sequences, at a Bash prompt, type Ctrl-V Ctrl-LeftArrow and Ctrl-V Ctrl-RightArrow, you should see:

^[OD^[OC

When you start a new session, the keys will be available or you can press Ctrl-xCtrl-r to re-read the ~/.inputrc file for the current session.

Understanding control characters in .inputrc

These are ANSI control-code escape sequences that are transmitted when various non alphanumeric keys are pressed on a "terminal" keyboard.

\e means the ASCII "ESCAPE" character (octal 033 hex 1B decimal 27). Which is part of a command sequence introduction (CSI).

Escape [ 2 ~ is a character sequence transmitted when you press the key labelled "Insert" on a VT220 (or later) terminal.

Many of these conventions have been adopted in software such as xterm and Linux consoles / shells - often extended in various, sometimes incompatible ways.

The use of these sequences in bash's READLINE function is described in the man pages for readline

       In  the  second  form,  "keyseq":function-name or macro, keyseq differs
       from keyname above in that strings denoting an entire key sequence  may
       be  specified  by  placing the sequence within double quotes.  Some GNU
       Emacs style key escapes can be used, as in the following example,  but
       the symbolic character names are not recognized.

          "\C-u": universal-argument
          "\C-x\C-r": re-read-init-file
          "\e[11~": "Function Key 1"

To get a list of which escape sequences correspond to which keyboard-keys, you can use a command such as infocmp -L -1 or infocmp -L -1 xterm

Best Answer

Related Solutions

Ubuntu – Putty SSH: CTRL+Cursor keys don’t work skip to previous/next word

Understanding control characters in .inputrc

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