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.

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





Commands by postrational from sorted by
Terminal - Commands by postrational - 5 results
sort -t $'\t' -k 2 input.txt
2010-07-11 12:58:51
User: postrational
Functions: sort

Use this BASH trick to create a variable containing the TAB character and pass it as the argument to sort, join, cut and other commands which don't understand the \t notation.

sort -t $'\t' ... join -t $'\t' ... cut -d $'\t' ...
cut -f 1 three-column.txt > first-column.txt
2010-07-11 10:13:45
User: postrational
Functions: cut

There is a common command for outputting a field or list of fields from each line in a file. Why wouldn't you just use cut?

dig -x
2009-09-28 15:13:34
User: postrational
Functions: dig

Performs a reverse DNS lookup, variants include:



curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | sed -n "s/<title>\(.*\)<\/title.*name>\(.*\)<\/name>.*/\2 - \1/p"
2009-09-07 21:56:40
User: postrational
Functions: awk sed tr

Checks the Gmail ATOM feed for your account, parses it and outputs a list of unread messages.

For some reason sed gets stuck on OS X, so here's a Perl version for the Mac:

curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | perl -pe 's/^<title>(.*)<\/title>.*<name>(.*)<\/name>.*$/$2 - $1/'

If you want to see the name of the last person, who added a message to the conversation, change the greediness of the operators like this:

curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | perl -pe 's/^<title>(.*)<\/title>.*?<name>(.*?)<\/name>.*$/$2 - $1/'