use strict;
my $str = '<title>Hello World</title>
<div style="margin:0px;" href="http://www.google.com" fadeout"="" src="../image.png" >
<img src="abc.jpg" alt="" />
<p style="margin-bottom:10px;">
The event is celebrating its 50th anniversary Kö
<a href="http://www.germany.travel/" style="margin:0px;">exhibition grounds in Cologne</a>.</p>
<p style="padding:0px;"></p>
<p style="color:black;"><strong>A festival for art lovers</strong></p>
</div>';
my $regex = qr/<([a-z][a-z0-9]*)(?:[^>]*?((?:\s(?:src|href|style)=['\"][^'\"]*['\"]){0,3}))[^>]*?(\/?)>/ip;
my $subst = '<$1$2$3>';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html