9.3.1 Event Designators

An event designator is a reference to a command line entry in the history list.

!

Start a history substitution, except when followed by a space, tab, the end of the line, ‘=’ or ‘(’ (when the extglob shell option is enabled using the shopt builtin).

!n

Refer to command line n.

!-n

Refer to the command n lines back.

!!

Refer to the previous command. This is a synonym for ‘!-1’.

!string

Refer to the most recent command starting with string.

!?string[?]

Refer to the most recent command containing string. The trailing ‘?’ may be omitted if the string is followed immediately by a newline.

^string1^string2^

Quick Substitution. Repeat the last command, replacing string1 with string2. Equivalent to !!:s/string1/string2/.

!#

The entire command line typed so far.