Category: perl

Self-tutoring about computer science: the tutor mentions using parentheses in Perl regular expressions to form groups.

A useful feature of regular expressions is the optional use of parentheses. There are numerous reasons to use them, but one is to report parts of the match.

Consider the following:

The output would be (assuming no typos:)

$1 denotes the contents of the first set of parentheses in the matching pattern, $2 the second, and so on. The groupings can be used to organize the output from the match.

Source:

perldoc.perl.org

roberts perl tutorial

More self-tutoring about Perl: the tutor mentions another way to enable ‘say’ in Perl.

In my post from Aug 15 I mention the Perl feature say and that, to enable it, a user might key

use v5.10;

below the she-bang line. (Apparently, a version past 5.10 may also suffice.)

I’ve read since that the line

use feature ‘say’;

also enables the use of say.

Source:

perldoc.perl.org

www.sthomas.net

Tutoring computer science, new language ideas will always be noticed. The tutor mentions the Perl construct say.

I’ve never known of say, but I tried it on a console and indeed, it works. I needed to include use v5.10; for say to work. I understand, however, that the version can be higher.

Source:

perldoc.perl.org