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

Commands by randy909 from sorted by
Terminal - Commands by randy909 - 9 results
tr "\n" " " < file
2010-12-08 16:13:54
User: randy909
Functions: tr
6

Even shorter. Stolen from comment posted by eightmillion.

grep -UIlr "^M" *
2010-08-20 21:16:34
User: randy909
Functions: grep
0

Where ^M is entered by ctrl-v-m (v then m). Especially useful on cygwin when checking into a version control system. If you're not using all cygwin tools (e.g. strawberry perl instead of cygwin perl) you'll find yourself dealing with this constantly.

-U tells grep to process the file as binary; it needs this to work

-I ignores binary files so you won't get false positives

-l only prints the filename instead of the offending lines

-r recursive

ls | sed 's,\(.*\),"\1",'
2010-08-17 14:27:27
User: randy909
Functions: ls sed
-2

I had a file named " " (one space) and needed a way to see what the real filename was so I could remove it. sed to the rescue.

echo "hello::::there" | tr -s ':'
2010-08-12 16:23:06
User: randy909
Functions: echo tr
1

This can be particularly useful used in conjunction with a following cut command like

echo "hello::::there" | tr -s ':' | cut -d':' -f2

which prints 'there'. Much easier that guessing at -f values for cut. I know 'tr -s' is used in lots of commands here already but I just figured out the -s flag and thought it deserved to be highlighted :)

echo StrinG | tr 'A-Z' 'a-z'
2010-08-12 15:42:56
User: randy909
Functions: echo tr
0

Another way to do it with slightly fewer characters. It doesn't work on Russian characters; please don't vote down because of that. :p It's very handy for those of us working in ascii :)

ls | sed s#^#$(pwd)/#
2010-08-04 20:47:44
User: randy909
Functions: ls sed
2

This version is a bit more portable although it isn't extended as easily with '-type f' etc. On AIX the find command doesn't have -maxdepth or equivalent.

find $(pwd) -maxdepth 1
2010-08-04 17:49:22
User: randy909
Functions: find
3

Prints contents of current directory with the full path prepended to each entry. You can add '-type f' if you don't want the directories to show up (for those less familiar with find). I can't believe ls doesn't have an option for this.

perl -MFile::Find=find -MFile::Spec::Functions -Tlwe 'find { wanted => sub { print canonpath $_ if /\.pm\z/ }, no_chdir => 1 }, @INC'
2010-08-02 15:18:51
User: randy909
Functions: perl
2

This version works on an AIX system on which I have very limited permissions. The other version fails with "Can't open file /usr/opt/perl588/lib/site_perl/5.8.8/aix/auto/DBI/.packlist".

find . -name "*.php" -print0 | xargs -0 grep -i "search phrase"
2010-07-27 20:52:37
User: randy909
Functions: find grep xargs
-2

xargs avoids having to remember the "{} \;" (although definitely a useful thing to know. Unfortunately I always forget it). xargs version runs 2x faster on my test fwiw.

edit: fixed to handle spaces in filenames correctly.