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

Randomize lines (opposite of | sort)

Terminal - Randomize lines (opposite of | sort)
cat ~/SortedFile.txt | perl -wnl -e '@f=<>; END{ foreach $i (reverse 0 .. $#f) { $r=int rand ($i+1); @f[$i, $r]=@f[$r,$i] unless ($i==$r); } chomp @f; foreach $line (@f){ print $line; }}'
2009-09-24 15:42:43
User: drewk
Functions: cat perl
0
Randomize lines (opposite of | sort)

The sort utility is well used, but sometimes you want a little chaos. This will randomize the lines of a text file.

BTW, on OS X there is no

| sort -R

option! There is also no

| shuf

These are only in the newer GNU core...

This is also faster than the alternate of:

| awk 'BEGIN { srand() } { print rand() "\t" $0 }' | sort -n | cut -f2-

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
random -f <file>
2009-09-24 19:15:58
User: haplo
3

random(6) - random lines from a file or random numbers

sort -R
2011-07-15 15:35:27
User: RyanM
Functions: sort
2

Randomizes a file. The opposite of sort is sort -R!

perl -wl -e '@f=<>; for $i (0 .. $#f) { $r=int rand ($i+1); @f[$i, $r]=@f[$r,$i] if ($i!=$r); } chomp @f; print join $/, @f;' try.txt
2009-12-21 21:15:55
User: JohnGH
Functions: join perl
0

print the lines of a file in randomized order

ls -1 | xargs ruby -e'puts ARGV.shuffle'

Know a better way?

If you can do better, submit your command here.

What others think

That misses line 1.

You can also do it with python and sed:

f="sortedfile.txt";l=$(cat "$f" | wc -l);for i in $(python -c "from random import *;print sample(xrange(1,1+$l),$l)"| tr -d "[,]"); do sed -n "$i"p "$f"; done
Comment by Escher 266 weeks ago

How is it that the perl program misses 1 line? head and tail of the output are 100% different that input.

Comment by drewk 265 weeks and 4 days ago

Your point of view

You must be signed in to comment.

Related sites and podcasts