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.

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

Join lines

Terminal - Join lines
echo -e "aa\nbb\ncc\ndd\n123" | sed -e :a -e "/$/N; s/\n/;/; ta"
2009-04-15 16:12:00
Functions: echo sed
-3
Join lines

Alternatives

There are 3 alternatives - vote for the best!

Terminal - Alternatives
cat file | tr "\n" " "
2010-12-02 09:21:02
User: uzsolt
Functions: cat file tr
9

It's works only when you replace '\n' to ONE character.

tr "\n" " " < file
2010-12-08 16:13:54
User: randy909
Functions: tr
7

Even shorter. Stolen from comment posted by eightmillion.

perl -pe 'eof()||s/\n/<SOMETEXT>/g' file.txt
2010-12-02 01:19:27
User: eightmillion
Functions: perl
3

This command turns a multi-line file into a single line joined with <SOMETEXT>. To skip blank lines, use:

perl -pe '(eof()||s/^\s*$//)||s/\n/<SOMETEXT>/g' file.txt
awk 'BEGIN{RS="\0"}{gsub(/\n/,"<SOMETEXT>");print}' file.txt
2010-12-12 21:43:22
User: __
Functions: awk
1

awk version of 7210. Slightly longer, but expanding it to catch blank lines is easier:

awk 'BEGIN{RS="\0"}{gsub(/\n+/,"<SOMETEXT>");print}' file.txt
cat file | tr -d "\n"
2010-12-02 09:22:02
User: uzsolt
Functions: cat file tr
-1

This command deletes the "newline" chars, so its output maybe unusable :)

Know a better way?

If you can do better, submit your command here.

What others think

now this will join your lines quite a bit more cleanly:

...| perl -pe "s/\n//"

Comment by linuxrawkstar 276 weeks and 1 day ago

If all you want is to join them with spaces,

... | xargs echo

works quite well.

Comment by clockworkavian 276 weeks ago

"just" join the lines of a 'file':

tr -d "\n" < file

or of a command's output:

command | tr -d "\n"

Comment by unefunge 191 weeks ago

Your point of view

You must be signed in to comment.

Related sites and podcasts