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?

score 29 · Accepted Answer · answered Dec 06 '13 at 18:11

29

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.

answered Dec 06 '13 at 18:11

Kent

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Know of an equivalent in gVim? – Jeff Dec 06 '13 at 22:05
@Jeff That works on gVim. I was on windows, so replaced $random with %random%. Rest just worked – Frison Alexander Dec 06 '13 at 22:08
I was trying this on windows but the command in the answer didn't work. So, I opened up vim inside cygwin and then it worked. – user674669 Apr 17 '16 at 00:43
@user674669 of course it won't work on windows, because there is no `$RANDOM` sys env on windows. `:!` will execute external command. Just like there is no `du, ls, readlink, cp ...` on windows. Well cygwin I don't have much experience.. – Kent Apr 18 '16 at 09:17
In addition, you could use `:r!echo $(($RANDOM \% 5 + 1))` to get a value between 1 and 6. Tweak values accordingly to get other ranges. – squirl Feb 04 '17 at 13:25

score 11 · Answer 2 · edited May 23 '17 at 11:54

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.

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.

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

For perl, `:put =system("perl -e `int(rand()*10)+1") can be tried, for example. :) — SibiCoder, Sep 09 '16 at 08:11

How to generate random numbers in the buffer?

2 Answers2