Commands by danam (9)

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands


Check These Out

List processes sorted by CPU usage

intercept stdout/stderr of another process or disowned process
Useful to recover a output(stdout and stderr) "disown"ed or "nohup"ep process of other instance of ssh. With the others options the stdout / stderr is intercepted, but only the first n chars. This way we can recover ALL text of stdout or stderr

Display the end of a logfile as new lines are added to the end

Get an IP address out of fail2ban jail
Removes an iptables rule created by fail2ban. This example shows how to remove a rule for an IP from the fail2ban-SSH chain. Can be used for any service monitored by fail2ban. For more on fail2ban, see http://www.fail2ban.org/wiki/index.php/Main_Page

list files recursively by size

Show URL/text in clipboard as QR code
Copy a URL (or Thai text, or whatever) and hit the keyboard shortcut for this fu to display it as a QR code. It's an "air gapped" way to send stuff to your phone [unlike google chart API etc.] as long as you watch out for cameras ;). dependencies [sudo apt-get install]: qrencode xclip xloadimage

Extract raw URLs from a file
you can also use cut instead of awk. less powerful but probably faster. ;)

Monitor the queries being run by MySQL
Watch is a very useful command for periodically running another command - in this using mysqladmin to display the processlist. This is useful for monitoring which queries are causing your server to clog up. More info here: http://codeinthehole.com/archives/2-Monitoring-MySQL-processes.html

Retry the previous command until it exits successfully
Repeat the previously used command (!!) until it exits with a success code (0). To put a delay between attempts you could do something like $ until !!; do sleep 5; done to wait 5 seconds after each attempt.

Read choice from user instantaneously
Usage exaple cmd $echo 'Sure to continue ??'; read -n1 choi; if [ "$choi" = 'y' ] || [ "$choi" = 'Y' ]; then echo -e '\nExecuting..'; else echo 'Aborted'; fi


Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: