N-Tron 9000 user manual here comes the usage of “!” command, available in history list

“!”

Command Name	!
Description	Repeats the command in the history list identified by <command-
	reference>.
	!!	– repeats the last command executed.
	!<n> – repeats the command in the history list associated
		with reference number <n>.
	!<str>	– repeats the most recent command that begins with
		the string <str>.
	Any non-whitespace characters that follow are appended to the
	referenced command prior to its execution.
Syntax	!<n>
	!<str>
Parameters	N
	It is the reference number of the command from history list
	that has to be repeated.
	str
	The most recent command from the history list that begins with
	keyword str.
Examples	N-TRON/Admin#[1]> !!
	Referenced command is not in the history list.
	N-TRON/Admin#[2]> !1
	Referenced command is not in the history list.
	N-TRON/Admin#[3]> !s
	Referenced command is not in the history list.
	N-TRON/Admin#[4]> whoami
	admin	with privilege of Administrator
	here comes the usage of “!” command
	N-TRON/Admin#[5]> !w
	whoami
	admin	with privilege of Administrator
	N-TRON/Admin#[6]> !2
	The above command will execute the second command, which is
	available in history list.
	N-TRON/Admin#[7]> !system
	The above command will execute the latest command in the history list
	that starts with system.
NOTES

(Revised 2010-7-2) page 96 of 145