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:



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.




Prints a file leaving out all blank lines and comment-only lines

Terminal - Prints a file leaving out all blank lines and comment-only lines
egrep -v "^\s*(#|$)" myfile.cfg
2011-12-08 15:25:17
User: dan
Functions: egrep
Prints a file leaving out all blank lines and comment-only lines

Does not print any line that either:

- is empty

- contains only spaces or tabs

- starts with #

- starts with spaces/tabs followed by a #


There are 5 alternatives - vote for the best!

Terminal - Alternatives

Know a better way?

If you can do better, submit your command here.

What others think

You got your useless cat award. Congratulations

Comment by zolden 172 weeks and 1 day ago

This, instead of dumping only lines containing only whitespace, will dump lines containing only "s". Probably not real useful, but you never know. :-)

Comment by trapperb 172 weeks and 1 day ago

Might be useful for boring configs with lots of comments, but as pointed above it needs backslash before that s because, currently it does NOT do what description says.

Comment by mwgamera 171 weeks and 6 days ago

For some reason the backslash does not show up. Here's the command:

cat boring.conf | egrep -v "^\s*(#|$)"
Comment by dan 171 weeks and 5 days ago


egrep -v "^\s*(#|$)" boring.conf

No need for cat(1).

Comment by atoponce 170 weeks and 5 days ago

Thanks @atoponce, much better. I've modified the command.

Comment by dan 170 weeks and 3 days ago

Your point of view

You must be signed in to comment.