execute last command.
execute the most recent command that starts with ‘top’ (e.g. !).
displays the command that !top would run (also adds it as the latest command in the command history).
execute the last word of the previous command (same as Alt +., e.g. if last command is ‘cat tecmint.txt’, then !$ would try to run ‘tecmint.txt’).
displays the word that !$ would execute.
displays the last word of the previous command.
displays the last word that !* would substitute.