It is probably worth pointing out what would happen if there weren't the parentheses "()" on the LHS of the assignment. Without the parentheses the assignment is in scalar rather than list context and records whether the match was successful (1) or not (empty string '') rather than assigning the list of captures in the match. The following script illustrates this

use strict;
use warnings;

my $dir = q{/some/path/to/afile};
print qq{\nMatching $dir\n};

print qq{\nWith parentheses, list context\n};
my ($fileName) =
   $dir =~ m{([^/]+)$};
print
   defined $fileName
   ? qq{-->$fileName<--\n}
   : qq{Not defined\n};

print qq{\nWithout parentheses, scalar context\n};
$fileName =
   $dir =~ m{([^/]+)$};
print
   defined $fileName
   ? qq{-->$fileName<--\n}
   : qq{Not defined\n};

$dir = q{/some/path/with/no/file/};
print qq{\nMatching $dir\n};

print qq{\nWith parentheses, list context\n};
($fileName) =
   $dir =~ m{([^/]+)$};
print
   defined $fileName
   ? qq{-->$fileName<--\n}
   : qq{Not defined\n};

print qq{\nWithout parentheses, scalar context\n};
$fileName =
   $dir =~ m{([^/]+)$};
print
   defined $fileName
   ? qq{-->$fileName<--\n}
   : qq{Not defined\n};
[download]

Here's the output

Matching /some/path/to/afile

With parentheses, list context
-->afile<--

Without parentheses, scalar context
-->1<--

Matching /some/path/with/no/file/

With parentheses, list context
Not defined

Without parentheses, scalar context
--><--
[download]

I hope this is of use.

Cheers,

JohnGG

---

---

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.