in reply to Re: extract linein thread extract line
$1, $2 (and $3, ..., etc.) hold the data that has been captured by a regular expression.
This is fairly basic stuff, so perhaps a read of the perlretut - Perl regular expressions tutorial would be useful; it's section "Extracting matches" has a better, and more detailed, description than my one sentence.
Conway's Game of Life
Perl regular expressions
My Magic 8-Ball™
Results (187 votes). Check out past polls.