Bash Magic Space

Sometimes, a little feedback is appreciated when writing some of the more complex Bash constructs. The “magic space” is one the things that can help us get quick feedback.

What does the “magic space” do?

Given the following:

$ find -wholename '*/path/to/file' -print -quit
$ man rm
$ rm -fv !-2:2

In the last line, feedback would be appreciated to see if we are indeed going to delete the second argument of two commands back. If you set Bash’ so-called “magic space”, history expansion will take place right away after typing a space after !-2:2:

$ rm -fv '*/path/to/file'

How to enable the magic space?

Put the following in your ~/.inputrc:

$if Bash
    Space: magic-space
$endif

Start a new session, or use bind -f ~/.inputrc to put the changes in effect immediately.

Other ways to achieve the same

You could also enable shopt -s histverify, which will perform the history expansion and give you another opportunity to modify the command before executing it. This requires you to press Enter, though.