Hide

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.


If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/

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.

Universal configuration monitoring and system of record for IT.
Hide

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:

Hide

News

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!
Hide

Top Tags

Hide

Functions

Hide

Credits

Commands using zgrep from sorted by
Terminal - Commands using zgrep - 5 results
zgrep -i "string" log.tar.gz
2014-09-12 20:31:13
User: elfinkind
Functions: zgrep
0

accomplishes the same thing without unzipping the whole file, and while i have never seen a log.tar.gz file that was a binary, i will concede that it might happen, so add the -a in there:

zgrep -ia "string" log.tar.gz

it's still shorter/easier to type...

zgrep --color=always 'get install' /var/log/apt/history.log*
2012-04-18 00:06:14
User: saherr1969
Functions: zgrep
Tags: zgrep apt-get
0

This will extract all the apt-get install commands issued on the box, even if they are in the gzipped history files.

zgrep CONFIG_MAGIC_SYSRQ /proc/config.gz
zgrep -h "" `ls -tr access.log*`
2010-06-19 09:44:05
User: dooblem
Functions: zgrep
2

I use zgrep because it also parses non gzip files.

With ls -tr, we parse logs in time order.

Greping the empty string just concatenates all logs, but you can also grep an IP, an URL...

zgrep "Failed password" /var/log/auth.log* | awk '{print $9}' | sort | uniq -c | sort -nr | less
2009-03-03 13:45:56
User: dbart
Functions: awk sort uniq zgrep
8

This command checks for the number of times when someone has tried to login to your server and failed. If there are a lot, then that user is being targeted on your system and you might want to make sure that user either has remote logins disabled, or has a strong password, or both. If your output has an "invalid" line, it is a summary of all logins from users that don't exist on your system.