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

Empty a file of contents

Terminal - Empty a file of contents
> [filename]
2011-05-18 14:59:02
User: bbbco
-3
Empty a file of contents

Ever need to erase the contents of a file and start over from scratch? This easy command allows you to do so. Be warned! This will immediately erase all the contents of your file and start you over from scratch (i.e. your file will be at 0 bytes, like if you touch a file).

Alternatives

There are 12 alternatives - vote for the best!

Terminal - Alternatives
truncate -s0 file
2009-10-24 16:31:03
User: pipping
17

The downside of output redirection is that you need permissions. So something like

> file

won't play nicely w/ sudo. You'd need to do something like

bash -c '> file'

instead, you could go w/

sudo truncate -s0 file
:> file
> file
> foobar.txt
truncate -s 0 file.txt
2012-07-30 06:50:30
User: quentin
0

Immediately make a file empty. This even works if the file is still being written to. Great for cleaning up huge log files!

Know a better way?

If you can do better, submit your command here.

What others think

I keep forgetting this and using 'echo -n "" > filename' instead.

Comment by Mozai 223 weeks and 4 days ago

Duplicate command. Please do search before posting...

Comment by FRUiT 223 weeks and 4 days ago

@FRUiT

Crap! I see that now! The suggested duplicates when you enter the new command never listed these past entries!

Comment by bbbco 223 weeks and 4 days ago

Your point of view

You must be signed in to comment.