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.

UpGuard checks and validates configurations for every major OS, network device, and cloud provider.

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



sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)

Terminal - sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)
se(){ while read a;do [ "$a" != "${a#*[email protected]*}" ]&&echo $a;done ;} # usage: se pattern # use in place of sed /pat/!d where RE are overkill
2011-04-06 03:37:40
User: argv
Functions: read sed
sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)

POSIX requires this "string truncating" functionality.

might as well use it, at least for very small tasks where invoking sed and using RE is overkill.


There are 2 alternatives - vote for the best!

Terminal - Alternatives

Know a better way?

If you can do better, submit your command here.

What others think

You need to quote "$a" in the echo or it'll drop multiple spaces from the input. e.g.

echo "a b"|se a

a b

Comment by splante 362 weeks and 4 days ago

splante: thank you.

i have also used this one-liner as a simple way to transform tabs to spaces,

e.g., where output from a program wraps on the terminal solely because it uses tabs, making it more difficult to read.

fstat | se pattern

if we quote the "$a" variable then of course we'll get the tabs.

but in other situations quoting "$a" is useful. e.g. to prevent the shell from expanding certain characters. imagine if some program is listening on an internet socket, and you do

netstat | se LIS

you might not like what you get for the output, unless you have put quotes around "$a".

it seems this website might also benefit from some added attention to shell quoting: i can only see one space between a and b in your example.

Comment by argv 362 weeks and 4 days ago

Your point of view

You must be signed in to comment.