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64 lines
1.4 KiB
ReStructuredText
64 lines
1.4 KiB
ReStructuredText
.. _cmd-random:
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random - generate random number
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===============================
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Synopsis
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--------
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::
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random
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random SEED
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random START END
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random START STEP END
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random choice [ITEMS...]
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Description
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-----------
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``random`` generates a pseudo-random integer from a uniform distribution. The
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range (inclusive) depends on the arguments.
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No arguments indicate a range of 0 to 32767 (inclusive).
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If one argument is specified, the internal engine will be seeded with the
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argument for future invocations of ``random`` and no output will be produced.
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Two arguments indicate a range from START to END (both START and END included).
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Three arguments indicate a range from START to END with a spacing of STEP
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between possible outputs.
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``random choice`` will select one random item from the succeeding arguments.
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Note that seeding the engine will NOT give the same result across different
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systems.
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You should not consider ``random`` cryptographically secure, or even
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statistically accurate.
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Example
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-------
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The following code will count down from a random even number between 10 and 20 to 1:
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::
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for i in (seq (random 10 2 20) -1 1)
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echo $i
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end
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And this will open a random picture from any of the subdirectories:
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open (random choice **.jpg)
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Or, to only get even numbers from 2 to 20::
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random 2 2 20
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Or odd numbers from 1 to 3::
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random 1 2 3 # or 1 2 4
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