正则表达式匹配包含特定属性值的所有xml标记

Question

I have an xml file where I want to match all xml tags that contain an attribute matching a certain string in Perl.

Sample XML:

<item attr="Car" />
<item attr="Apple_And_Pears.htm#123" />
<item attr="Paper" />
<item attr="Orange_And_Peach.htm#213" />

I want a regex that grabs all nodes that has an attribute that contains ".htm"

<item attr="Orange_And_Peach.htm#213" />
<item attr="Apple_And_Pears.htm#123" />

With the following regex, I'm matching with all tags rather than only tags with .htm attribute:

<item.*?attr="[^>]*>

Is there some sort of positive lookahead until a certain character?

Thanks

Answer 1

The appropriate Perl solution is not regex. With Mojo::DOM (one of many options):

use strict;
use warnings;
use Mojo::DOM;
use File::Slurper 'read_text';

my $xml = read_text 'test.xml';
my $dom = Mojo::DOM->new->xml(1)->parse($xml);
my $tags = $dom->find('item[attr*=".htm"]');
print "$_\n" for @$tags;

Answer 2

As Grinnz suggested you should use an approriate xml-parser (check out this interesting post on stackoverflow explaining why), but since you asked for it here's a simple regex you could use with a positive lookahead:

<item.*?attr=".*(?=\\.htm).*

If you want to match tags with only one ".htm" in it, you can use both a negative and positive lookaround:

^(?:(?!\\.htm).)*\\.htm(?!.*\\.htm).*$