Replaying Linux CLI commands with history

Very handy little snippet I discovered today, mostly here for my own reference in future.

It’s handy to be able to re-play/re-submit commands that you’ve typed into the CLI before on your Linux box, to do this you can use the history command.

Let’s take a look at my webserver hosting the site, just as an example:

root@web:~# history
  781  nano /etc/cron.hourly/.placeholder sess_
  782  crontab
  783  crontab -e
  784  nano /etc/cron.d/php5
  785  sudo bash
  786  exit
  787  sudo bash
  788  service php5-fpm restart
  789  service nginx restart
  790  service varnish restart

If I want to look for particular entries I can just grep the output:

root@web:~# history | grep "cat"
 1005  cat /etc/nginx/sites-enabled/default
 1006  cat /etc/nginx/sites-enabled/www.mylesgray.com
 1027  cat mini/README.txt
 1137  cat var/report/1084963200249

Then if you pay attention to the left hand column, there is a history number, to re-enter a command we simple put a bang (!) in front of the number in the CLI:

root@web:~# !1006
cat /etc/nginx/sites-enabled/www.mylesgray.com
## https://blah.cloud -> https://blah.cloud
server {
.
.
.
etc

If you want to execute the very last command you typed:

root@web:~# !!

If you want to execute a command issued n commands previous:

root@web:~# !-n

If you want to execute the last command starting with word:

root@web:~# !word

If you want to execute the last command containing word:

root@web:~# !?word

If you want to view the parameters passed to the last command:

root@web:~# !*

If you want to view the parameters passed to command n commands previous:

root@web:~# !-n*

As you can see, plenty of options, these are by no means exhausted, you can combine them to create any kind of filter in-between.

Bonus extra tip - if you forgot to add sudo to a command that requires it (because we all do) this will repeat the last command, with sudo prefixed to it:

root@web:~# sudo !!

Why not follow @mylesagray on Twitter ↗ for more like this!