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).

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#*$@*}" ]&&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
1
Up
Down
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.

Add to favourites | Report as malicious

Alternatives

There is 1 alternative - 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 110 weeks and 2 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 110 weeks and 1 day ago

Your point of view

You must be signed in to comment.

Related sites and podcasts