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True Random Dice Roll

Terminal - True Random Dice Roll
tr -cd '1-6' < /dev/urandom | head -c 1; echo
2012-09-21 02:16:42
User: atoponce
Functions: head tr
9
True Random Dice Roll

/dev/urandom is cryptographically secure, and indistinguishable from true random, as it gathers data from external sources, influenced by human timing interactions with computers, to fill the entropy pool, and hashes the input with SHA-1. As such, this is a quick way to do a "true random" fair-6 dice roll. Using this method, you could easily create passphrases with Diceware http://diceware.com.

Change the head(1) count to something other than 5 for more or less numbers.

Alternatives

There are 6 alternatives - vote for the best!

Terminal - Alternatives
echo $(</dev/urandom tr -dc 1-6 | head -c1)

Know a better way?

If you can do better, submit your command here.

What others think

Hmmm. Not quite true random. From one byte of randomness mod 6 there are 43 possible 0-3s and only 42 possible 4-5s - therefore your die is weighted against fives and sixes. Perhaps echo $(

Comment by unixmonkey40000 219 weeks and 3 days ago

You are absolutely right. However, it's biased away from 5 and 6 by 2 percent. So, you could update the command to read more bytes. Reading 2 bytes would produce a bias away from 5 and 6 by 9 thousandths of one percent. Reading 3 bytes would produce a bias away from 5 and 6 of 4 one-hundred thousandths by one percent. I would be willing to bet that standard fabricated dice have a larger bias towards some numbers than that. So, for practical purposes, reading only 10 bytes, would be more than sufficient, and certainly "close enough". I've updated the post.

Comment by atoponce 219 weeks and 2 days ago

Updated command with a much improved algorithm.

Comment by atoponce 43 weeks and 2 days ago

Your point of view

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