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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.
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Random Number Between 1 And X

Terminal - Random Number Between 1 And X
echo $[RANDOM%X+1]
2010-08-07 02:43:46
Functions: echo
Random Number Between 1 And X

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.


There is 1 alternative - vote for the best!

Terminal - Alternatives
od -An -N1 -tu1 /dev/random
2013-09-10 08:57:16
User: sucotronic
Functions: od

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

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

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

This is /bin/sh compatible.

Know a better way?

If you can do better, submit your command here.

What others think

The $[] form is deprecated. Use $(()) instead.

Comment by dennisw 311 weeks and 6 days ago

This is simple, but not sh compatible.

Just bash compatible.

Il prefer the awk version.

Comment by dooblem 311 weeks and 3 days ago

num-utils has a 'random' function where you just have to do:

random 1..5
Comment by matthewbauer 311 weeks and 3 days ago

The solution is wrong, or at least not well explained, because X have to be lower than 32767 (see man bash)

The awk version is ok, but you've to know that the seed generation is based in clock, so if you ask for numbers in a certain interval, you'll get the same numbers!!

num-utils package contains numrandom command, but it is not very efficient, because it generates a list of numbers and then picks one :P

Comment by sucotronic 150 weeks and 3 days ago

how can i give x like an argument betweeen 100-100000

Comment by gerih26 132 weeks and 4 days ago

Your point of view

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