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.

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



Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

Base conversions with bc

Terminal - Base conversions with bc
echo "obase=2; 27" | bc -l
2009-03-25 09:54:50
User: polar
Functions: bc echo
Base conversions with bc

Easily convert numbers to their representations in different bases. Passing

"ibase=16; obase=8; F2A"

to bc will convert F2A (3882 in decimal) from Hex to Octal, and so on.


There are 11 alternatives - vote for the best!

Terminal - Alternatives

Know a better way?

If you can do better, submit your command here.

What others think

seems to me that this doesn't work all the time:

This is correct:

echo "ibase=2; obase=4; 01100001"|bc -l 1201

But the following aren't:

This one outputs the answer in base 3, not base 16:

echo "ibase=2; obase=16; 01100001"|bc -l 10121

This one doesn't do any conversion at all:

echo "ibase=2; obase=10; 01100001"|bc -l 1100001

and here's a workaround that seems to do what it should, with the added benefit of being able to supply the number on stdin:

echo "obase=16;$(echo "ibase=2;$(head -n 1)"|bc)"|bc
Comment by camocrazed 358 weeks and 5 days ago

I stand corrected. Setting the ibase changes it for all the following numbers, including the one supplied to obase, but only for multi-digit numbers.

A better workaround to this than my previous one is to simply put obase first

"obase=16; ibase=2; 01100001"|bc -l 61
Comment by camocrazed 358 weeks and 4 days ago

Your point of view

You must be signed in to comment.