Re: how to run regex calculation

Oh. Heh. I misunderstood the intent. I thought you wanted to match a
sequence of digits followed by a space followed by more digits followed by
a space followed by the first set of digits repeated 0 or more times
followed by the second set of digits. If you want multiplication then
Joseph He's original answer was correct.

Yves

On Thu, 9 Jan 2020, 09:40 Wesley Peng, <[email protected]> wrote:

> Hallo
>
> on 2020/1/9 16:35, demerphq wrote:
> > $str=~/(\d+)\s(\d+)\s(\1*\2)/
> >
> > $1 refers to the capture buffers from the last completed match, \1
> > inside of the pattern part of a regex refers to the capture buffer of
> > the currently matching regex.
>
> This doesn't work too.
>
> perl -Mstrict -le 'my $str = "2 3 6"; print "true" if
> $str=~/(\d+)\s(\d+)\s(\1*\2)/'
>
> nothing printed.
>
>
> Regards.
>