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, <wes...@magenta.de> 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. >
