What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. 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.

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

UpGuard checks and validates configurations for every major OS, network device, and cloud provider.

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:



May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

Top Tags



Polls fos network port usage

Terminal - Polls fos network port usage
while sleep 1; do date; (netstat -a -n | grep 80) ; done
2011-05-16 07:56:56
User: hute37
Functions: grep netstat sleep
Polls fos network port usage


There are 5 alternatives - vote for the best!

Terminal - Alternatives
watch 'netstat -anptu |egrep "^Proto|:80 "'
2011-05-18 15:05:52
User: Mozai
Functions: egrep watch

Shows updated status in a terminal window for connections to port '80' in a human-friendly form. Use 'watch -n1' to update every second, and 'watch -d' to highlight changes between updates.

If you wish for status updates on a port other than '80', always remember to put a space afterwards so that ":80" will not match ":8080".

Know a better way?

If you can do better, submit your command here.

What others think

watch lsof -i :80

Comment by zolden 362 weeks and 3 days ago

netstat already has '-c' option for continuous (once-per-second) output. You can pipe the output to grep, no need for subshells. zolden has the right idea: for human-readable status updates, use /usr/bin/watch.

Furthermore, 'grep 80' will also match ports 8000 and 8080, process IDs 80 and 800, and any IP address with '.80' in it.

Comment by Mozai 362 weeks and 1 day ago

Your point of view

You must be signed in to comment.