Command Line Recall

Once you punch in a command, it gets saved in your shell's history list. This list persists in your current shell session until you call it quits. After you exit, the list gets saved to a history file, ready for a rerun in your next session.

If you dig up an old command in a subsequent shell session, you can always give it a tweak in the same fashion we saw earlier.

The history Command

To view your history list, use the history command. Enter the command without any additional options, or optionally followed by a number, to list that many of the most recent commands. For example:

history 8
382 date 
383 ls /usr/bin | sort -a | more 
384 man sort 
385 cd /usr/local/bin 
386 man more 
387 useradd -m /home/chris -u 101 chris 
388 passwd chris 
389 history 8

As you can see from the output, a number precedes each command line in the list. You can recall one of those commands using an exclamation point (!), followed by the number that correlates against your desired command:

!382

Alternatively, to simply repeat the most recent command, you can enter the following:

!!

Keep in mind that when an exclamation point is used, the command runs blind without presenting an opportunity to confirm the command you’re referencing...