How to generate random numbers in the buffer?

Question

I want to generate 10 random numbers in the buffer.

In Emacs I would do:

<start macro>(random limit) <eval lisp><newline><end macro> to define the macro,

and 9 <execute macro> to generate it 10 times.

Is there a way I can do this in vim?

Answer 1

is this ok for you?

:r! echo $RANDOM

then

9@:

if you have certain programming language env available on your OS, you can eval those statement too.

Answer 2

Vim doesn't offer native random generator, however if you have vim compiled with Python, the following method will append a random digit at the end of your line:

:py import vim, random; vim.current.line += str(random.randint(0, 9))

^{Note: To check if your vim supports Python, try: :echo has('python') (1 for yes).}

You can also use shell which offers $RANDOM variable as Kent suggested (works with bash/ksh/zsh) which returns a pseudorandom (0-32767), in example:

:put =system('echo $RANDOM')

or:

:r! od -An -td -N1 /dev/urandom

^{On Windows, you've to have Cygwin/MSYS/SUA installed, or use %RANDOM% variable as Carpetsmoker suggested.}

If you don't have access to shell and Python, as for workaround, you use last few digits from the current timestamp, in example:

:put =reltimestr(reltime())[-2:]

^{Note: If you're using it quite often, write a simple function which will return reltimestr(reltime())[-4:].}

Note: Above methods returns only a pseudorandom integer which should not be used to generate an encryption key.

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To add more random numbers please press @: to repeat the command again. Or prefix with number (like 10@:) to add much more of random numbers separated by new lines.

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Related:

• How to generate random numbers? at Vim SE
• Generate random number in bash at stackoverflow SE