On November 25, 1999 at 20:53, Harry Putnam wrote:
> This is really more of a "wilma" question, if that is inappropriate
> here, let me know.
I no very little about wilma, but I can answer one of your questions.
> ## # [ wilma wilma_reindex ]
> ## # A Perl regular expression returning the year and month numbers
> ## # in $1 and $2, respectively, from the HTML archive directory
> ## # name. Backslashes must be doubled due to configuration variable
> ## # interpolation.
> ##
> ## ARC_REGEX = ((?:19|20)?\\d\\d)(\\d\\d)$
$1 -----^^^^^^^^^^^^^^^^ ^^^^^^---- $2
> What does it mean in perleze to say " A Perl regular expression
> returning the year and month numbers in $1 and $2, respectively,.."
>
> What does $1 and $2 refer to?
They are backreferences. Anytime you use ()'s in a Perl regex,
if there is match, the value is stored in a backreference variable
starting with $1. $2 is the seconds set of ()'s, $3 is the third
set of ()'s, and so on.
> Also spent about 2 hr on the MHonArc maillist archive, enough to learn
> quite a bit but also to get my head spinning.
That will do it.
--ewh
