It seems a little odd to me to just change characters for something like that and expect perl to "know" that's what they are there for. Does it really work that way?

Yes, it does really work that way... more or less.

The one catch is that, when you use alternate delimiters, you have to explicitly use either "m" or "s" at the beginning of the regex. The "m" and "s" are the actual operators which (in the right context) trigger a regex operation, so when perl sees those followed by punctuation, it recognizes that the punctuation used will be the delimiter for that regex without needing to expicitly set or reset anything.

So, for example, all of these variations are equivalent:

#!/usr/bin/perl

use strict;
use warnings;

my $text = 'This is a text string.';

print $text =~ m/is a/, " - m//\n";

# Default delimiter, so the "m" can be omitted
print $text =~ /is a/, " - //\n";

# Custom delimiters, so the "m" is mandatory
print $text =~ m#is a#, " - m##\n";
print $text =~ m!is a!, " - m!!\n";
print $text =~ m^is a^, " - m^^\n";

# Open/close punctuation is used in pairs
print $text =~ m[is a], " - m[]\n";
print $text =~ m(is a), " - m()\n";
print $text =~ m<is a>, " - m<>\n";
[download]

The print on each regex displays the number of matches found along with the delimiters used:

1 - m//
1 - //
1 - m##
1 - m!!
1 - m^^
1 - m[]
1 - m()
1 - m<>
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.