use strict;
my $str = '<p>Nissan is car manufacter odoocompany.</p>
<p>Nissan</p>
<p>Nissan. Nissan, Nissan: \'Nissan\' "Nissan" Nissan. </p>
<p>niss \'Nissan\' niss</p>
<p>[Nissan] (Nissan)</p>
<p>Nissan! www.Nissan.com and www.Nissan.co.in/?nissan=/Nissan.php </p>
<p>Nissan! www.Nissan.com/nissanis/nissan01/nissan_-ABC/nissan.com</p>
<p>nissan.com/nissan.html nissan company Nissan Micra is product</p>
<p><a href="www.Nissan.com">Nissan</a> is company and <span><a href="www.Nissan.com">Nissan</a></span> Micra is product</p>
<p><span>Nissan</span></p>
<p>Nissan product <a href="Nissan.com">Nissan</a> ignore Nissan</p>
<p>nissan <a href="Nissan.com"><span>Nissan</span></a> new nissan</p>
<p>odoo is a name Company and Nissan Micra is a model of best.</p>
<p>This is new <a href=\'https://www.Nissan.com\'><span>Nissan</span></a> micra of micra nissan is company.
nissan is a company.</p>';
my $regex = qr/(?<!(?=((http|https|ftp|ftps?)\:\/\/?)(www\.?)))Nissan(?!(?:([$&+.,/:;\-_#=@?!a-zA-Z0-9](?!\s))+))(?=[^<>]*<)(?!(?:(?!</?(?:a|span)[ >/])(?:.|\n))*</(?:a|span)>)(?! (Micra|is))/ip;
if ( $str =~ /$regex/g ) {
print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n";
# print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n";
# print "Capture Group 2 is $2 ... and so on\n";
}
# ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p'
# Named capture groups can be called via $+{name}
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