Re: elisp question

[Tim McNamara <timmcn@bitstream.net>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> The files are in a subdirectory (called kaya), numbered 1 to
>> whatever, so I want to randomly pick an integer from 1 to whatever.
>> I thought that (find-file) or perhaps (find-file-noselect) could be
>> used in conjunction with (random), but I can't figure out how to do
>> that.  I've probably missed something really bloody obvious in the
>> elisp manual...
>
> (pop-to-buffer
>  (find-file-noselect (expand-file-name (number-to-string (random N))
>                                        "foo/bar/kaya")))
>
> This assumes the file names go from 0 to N-1.
>
> You could also do
>
>   (let ((files (directory-files "foo/bar/kaya" 'full "[^.]\\|...")))
>     (pop-to-buffer (find-file-noselect (nth (random (length files)) files))))
>
> and just select any random file in the directory, without any assumption on
> the file names used.

That looks simpler than what I was thinking, although I'll have to go
through it argument by argument to make sure I understand it.  I was
expecting to have to count the number of files in the directory, then
use that number as the limit to (random), and somehow be able to make
(find-files) use the result from (random) as the name of the file to
be read into the buffer. Simpler is better!

I'll test and post the results.  Thanks!