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Readline is a library by the GNU Project, used by Bash and other CLI-interface programs to edit and interact with the command line. Before reading this page please refer to the library home page as only subtle configuration will be introduced here.
By default Readline uses Emacs style shortcuts for interacting with command line. However, vi style editing interface is also supported. If you are a vi or vim user, you may want to put the following line to your
~/.inputrc to enable vi-like keybindings:
set editing-mode vi
Alternatively, to use the vi-like keybindings, you may add the following line to your
set -o vi
Usually, pressing the up arrow key will cause the last command to be shown regardless of the command that has been typed so far. However, users may find it more practical to list only past commands that match the current input.
For example, if the user has typed the following commands:
In this situation, when typing
ls and pressing the up arrow key, current input will be replaced with
man mount, the last performed command. If the history search has been enabled, only past commands beginning with
ls (the current input) will be shown, in this case
You can enable the history search mode by adding the following lines to
If you are using vi mode, you can add the following lines to
~/.inputrc (from this post):
set editing-mode vi $if mode=vi set keymap vi-command # these are for vi-command mode "\e[A": history-search-backward "\e[B": history-search-forward set keymap vi-insert # these are for vi-insert mode "\e[A": history-search-backward "\e[B": history-search-forward $endif
If you chose to add these lines to
~/.inputrc, it is recommended that you also add the following line at the beginning of this file to avoid strange things like this:
Alternatively, one can use reverse-search-history (incremental search) by pressing
Ctrl+R, which does not search based on previous input but instead jumps backwards in the history buffer as commands are typed in a search term. Pressing
Ctrl+R again during this mode will display the previous line in the buffer that matches the current search term, while pressing
Ctrl+G (abort) will cancel the search and restore the current input line. So in order to search through all previous
mount commands, press
Ctrl+R, type 'mount' and keep pressing
Ctrl+R until the desired line is found.
The forward equivalent to this mode is called forward-search-history and is bound to
Ctrl+S by default. Beware that most terminals override
Ctrl+S to suspend execution until
Ctrl+Q is entered. (This is called XON/XOFF flow control). For activating forward-search-history, either disable flow control by issuing:
$ stty -ixon
or use a different key in
inputrc. For example, to use
Alt+S which is not bound by default:
If you repeat the same command several times, they will all be appended in your history. To prevent this, add to your
To disable logging of lines beginning with a space add this to your
~/.bashrc already contains
replace it with
Readline also supports binding keys to keyboard macros. For simple example, run this command in Bash:
bind '"\ew":"\C-e # macro"'
or add the part within single quotes to inputrc:
"\ew":"\C-e # macro"
Now type a line and press
W. Readline will act as though
Ctrl+E (end-of-line) had been pressed, appended with '
Use any of the existing keybindings within a readline macro, which can be quite useful to automate frequently used idioms. For example, this one makes
Ctrl+Alt+L append "| less" to the line and run it (
Ctrl+M is equivalent to
"\e\C-l":"\C-e | less\C-m"
The next one prefixes the line with 'yes |' when pressing
Ctrl+Alt+Y, confirming any yes/no question the command might ask:
"\e\C-y":"\C-ayes | \C-m"
This example wraps the line in
su -c '', if
Alt+S is pressed:
"\es":"\C-a su -c '\C-e'\C-m"
As a last example, quickly send a command in the background with
Ctrl+Alt+B, discarding all of its output:
"\e\C-b":"\C-e > /dev/null 2>&1 &\C-m"
Tips and tricks
Disabling control echo
Due to an update to
Ctrl+C is pressed. For users who wish to disable this, simply add the following to
set echo-control-characters off