readline

Bind key sequence to text

bind '"\C-ab": "you typed control a followed by a b"'

Bind key sequence to command

With the following bind command, date is executed when ,dt is typed, yet, the already typed text in the command line remains.

bind -x '",dt": "date"'

Within the command, the variables READLINE_LINE and READLINE_POINT provide access to the content and cursor position of the text currently being edited.

If the command is a function (that executes in the same process as the shell, rather than a script that executes as a child process), these variables can even be written to and thus the edited line can be changed.

Apparently, it's not possible to associate a key sequence to commands in inputrc like initialization files.

Programmatically change current line

With bind -x, not only an ordinary executable, but also a shell function can be called. The function can then read and write the variables READLINE_POINT (zero based position of cursor on line) and READLINE_LINE (text of current line).

In the following example, a bash - regular expressions and BASH_REMATCH are used to cut everything after the last slash.

This might be useful when doing something like cd /foo/bar/baz/xyz and then finding out that xyz was the wrong directory. ctrl-q goes then back one directory.

removeLastPartOfPath() { # {

  # If READLINE_LINE ends on something like $SOMETHING/foo/bar/baz
  # $SOMETHING/foo/bar is assigned to READLINE_LINE.

  if [[ $READLINE_LINE =~ (.*)/ ]]; then
     READLINE_LINE="${BASH_REMATCH[1]}"
  fi
} # }

# Trying to bind ctlr-q to removeLastPartOfPath {
# 
#     ctrl-q is used by the tty for flow control (xon/xoff).
#     I couldn't care less (at least momentarely), so
#     flow control is turned off (stty -ixon) in order to make it possible
#     to bind ctrl-q to a function
#
stty -ixon

bind -x '"\C-q": removeLastPartOfPath'

Modes

Two modes: vi (set -o vi) and emacs (set -o emacs).

Various

ctrl-t exchanges the letter before the cursor with the second letter before the cursor.

In order to bind ctrl-q, flow control must be turned off (stty -ixon).