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

Random password generating function

Terminal - Random password generating function
mkpasswd() { head -c $(($1)) /dev/urandom | uuencode - | sed -n 's/.//;2s/\(.\{'$1'\}\).*/\1/p' ;}
2009-11-19 14:27:52
User: taliver
Functions: head sed uuencode
-3
Random password generating function

This uses urandom to produce a random password. The random values are uuencoded to ensure only printable characters. This only works for a number of characters between 1 and 60.

Alternatives

There are 3 alternatives - vote for the best!

Terminal - Alternatives
< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6
2009-02-24 09:43:40
User: Blackbit
Functions: head tr
11

If you want a password length longer than 6, changing the -c6 to read -c8 will give you 8 random characters instead of 6. To end up with a line-feed, use this with echo:

# echo `< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6`

dd if=/dev/urandom count=200 bs=1 2>/dev/null | tr "\n" " " | sed 's/[^a-zA-Z0-9]//g' | cut -c-16
openssl rand 6 -base64
2011-10-05 14:24:41
User: Le_Jax
0

just change 6 to 9 or 12 or more (multiple of 3) to have bigger password

Know a better way?

If you can do better, submit your command here.

What others think

Actually, you can just do "head -c $1". I originally was diving by 3 to reduce the amount of random characters needed (in case I switched to random), but then forgot that I stopped doing any math on the value.

Comment by taliver 368 weeks and 2 days ago

And, actually, a little smaller is:

mkpasswd() { head -c $1 /dev/urandom | uuencode - | sed -n '2s/.\(.\{'$1'\}\).*/\1/p' ;}

Comment by taliver 368 weeks and 2 days ago

Your point of view

You must be signed in to comment.