July 2005
Intermediate to advanced
544 pages
13h 8m
English
Content preview from Perl Best PracticesBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 12. Regular Expressions
Some people, when confronted with a problem, think: "I know, I'll use regular expressions". Now they have two problems.
—
Regular expressions are one of the signature features of Perl, providing it with most of the practical extraction facilities for which it is famous. Many of those who are new to Perl (and many who aren't so new) approach regexes with mistrust, trepidation, or outright fear.
And with some justification. Regexes are specified in a compact and sometimes baroque syntax that is, all by itself, responsible for much of Perl's "executable line noise" reputation. Moreover, in the right hands, patterns are capable of performing mystifying feats of text recognition, analysis, transformation, and computation[62].
It's no wonder they scare so many otherwise stalwart Perl hackers.
And no surprise that they also figure heavily in many suboptimal programming practices, especially of the "cut-and-paste" variety. Or, more often, of the "cut-and-paste-and-modify-slightly-and-oh-now-it-doesn't-work-at-all-so-let's-modify-it-some-more-and-see-if-that-helps-no-it-didn't-but-we're-committed-now-so-maybe-if-we-change-that-bit-instead-hmmmm-that's-closer-but-still-not-quite-right-maybe-if-I-made-that-third-repetition-non-greedy-instead-oops-now-it's-back-to-not-matching-at-all-perhaps-I-should-just-post-it-to-PerlMonks.org-and-see-if-they-know-what's-wrong" variety.
Yet the secret to taming regular expressions is remarkably simple. You merely ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.