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.


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.
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

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!
Hide

Top Tags

Hide

Functions

Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

Join lines

Terminal - Join lines
cat file | tr "\n" " "
2010-12-02 09:21:02
User: uzsolt
Functions: cat file tr
8
Join lines

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

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
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 :)

echo -e "aa\nbb\ncc\ndd\n123" | sed -e :a -e "/$/N; s/\n/;/; ta"

Know a better way?

If you can do better, submit your command here.

What others think

This also replaces the final new line, which may not be something a person wants to do. The cat is also unnecessary.

tr "\n" " " < file
Comment by eightmillion 313 weeks and 6 days ago

Your point of view

You must be signed in to comment.