mirror of
https://github.com/fish-shell/fish-shell.git
synced 2024-11-30 14:24:35 +08:00
65 lines
1.4 KiB
ReStructuredText
65 lines
1.4 KiB
ReStructuredText
.. _cmd-random:
|
|
|
|
random - generate random number
|
|
===============================
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
::
|
|
|
|
random
|
|
random SEED
|
|
random START END
|
|
random START STEP END
|
|
random choice [ITEMS...]
|
|
|
|
Description
|
|
-----------
|
|
|
|
``random`` generates a pseudo-random integer from a uniform distribution. The
|
|
range (inclusive) depends on the arguments.
|
|
No arguments indicate a range of 0 to 32767 (inclusive).
|
|
|
|
If one argument is specified, the internal engine will be seeded with the
|
|
argument for future invocations of ``random`` and no output will be produced.
|
|
|
|
Two arguments indicate a range from START to END (both START and END included).
|
|
|
|
Three arguments indicate a range from START to END with a spacing of STEP
|
|
between possible outputs.
|
|
``random choice`` will select one random item from the succeeding arguments.
|
|
|
|
Note that seeding the engine will NOT give the same result across different
|
|
systems.
|
|
|
|
You should not consider ``random`` cryptographically secure, or even
|
|
statistically accurate.
|
|
|
|
Example
|
|
-------
|
|
|
|
The following code will count down from a random even number between 10 and 20 to 1:
|
|
|
|
::
|
|
|
|
for i in (seq (random 10 2 20) -1 1)
|
|
echo $i
|
|
end
|
|
|
|
|
|
And this will open a random picture from any of the subdirectories:
|
|
|
|
::
|
|
|
|
open (random choice **.jpg)
|
|
|
|
|
|
Or, to only get even numbers from 2 to 20::
|
|
|
|
random 2 2 20
|
|
|
|
Or odd numbers from 1 to 3::
|
|
|
|
random 1 2 3 # or 1 2 4
|