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Random Number Between 1 And 256

Terminal - Random Number Between 1 And 256
od -An -N1 -tu1 /dev/random
2013-09-10 08:57:16
User: sucotronic
Functions: od
6
Random Number Between 1 And 256

It takes a byte from /dev/random whose source is the kernel entropy pool (better source than other solutions).

Alternatives

There are 7 alternatives - vote for the best!

Terminal - Alternatives
echo $[RANDOM%X+1]
2010-08-07 02:43:46
Functions: echo
26

If X is 5, it will about a number between 1 and 5 inclusive.

This works in bash and zsh.

If you want between 0 and 4, remove the +1.

awk 'BEGIN { srand(); print rand() }'
2010-08-07 14:33:12
User: dennisw
Functions: awk
Tags: random number
-2

2d6 dice:

awk 'BEGIN { srand(); a=int(rand()*6)+1; b=int(rand()*6)+1; print a " + " b " = " a+b }'

3 + 6 = 9

echo "$(od -An -N4 -tu4 /dev/urandom) % 5 + 1" | bc
2010-08-10 12:10:21
User: dooblem
Functions: echo
-4

This is /bin/sh compatible.

Know a better way?

If you can do better, submit your command here.

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Comment by shoesus30 98 weeks and 5 days ago

Unless you know you need it (and for small ints you don't), /dev/urandom is the better choice to use in programs:

Reading /dev/random can block other programs from getting entropy! (see https://en.wikipedia.org/wiki/Urandom)

Comment by zvyn 98 weeks and 5 days ago

zvyn > of course this is not intended to be used in a iterative script, I only wanted a 'true' random number (or the thing more near to it)

Comment by sucotronic 98 weeks and 5 days ago

Your point of view

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