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3a23fdf359
Includes harmonizing the display of options and arguments, standardising terminology, using the envvar directive more broadly, adding help options to all commands that support them, simplifying some language, and tidying up multiple formatting issues. string documentation is not changed.
69 lines
1.5 KiB
ReStructuredText
69 lines
1.5 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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.. synopsis::
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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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The **-h** or **--help** option displays help about using this command.
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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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::
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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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