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.

OpenID
or
Sign in Register

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

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

2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.
Hide

Tags

Hide

Functions

Hide

Credits

Site by David Winterbottom (user root).

Empty a file of contents

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

Show sample output | Add to favourites | Report as malicious

Alternatives

There are 4 alternatives - vote for the best!

Terminal - Alternatives
> file.txt
2009-01-26 10:22:31
User: root
288
Up
Down
Empty a file

For when you want to flush all content from a file without removing it (hat-tip to Marc Kilgus).

Comments (16) | Add to favourites | Report as malicious
truncate -s0 file
2009-10-24 16:31:03
User: pipping
11
Up
Down
Empty a file

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
Comments (1) | Add to favourites | Report as malicious
:> file
2010-09-23 12:33:55
User: krissi
11
Up
Down
Empty a file
Comments (0) | Add to favourites | Report as malicious
> file
2010-12-26 14:17:13
User: Juev
8
Up
Down
Create a new file
Comments (0) | Add to favourites | Report as malicious
> foobar.txt
2009-12-29 08:08:15
User: unixmonkey7657
5
Up
Down
Empty a file
Comments (1) | Add to favourites | Report as malicious

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 104 weeks and 4 days ago

Duplicate command. Please do search before posting...

Comment by FRUiT 104 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 104 weeks and 4 days ago

Your point of view

You must be signed in to comment.

Related sites and podcasts