use strict;
my $str = '[URL]www.no.http.example.com[/URL]
[url]https://any.com/any[/url]
[url="nourl"]nourl[/url]
[URL="https://any.com/any?any=333"]text text[/URL]
[url="http://www.emptyTEXT.com"][/url]
[url]http://www.any.com/any?any=44#sss[/url]';
my $regex = qr~\[url
(?|
] ((https?://[^[]+))
|
(?:="(https?://[^"]+)")] (.+?)
)
\[/url]~ixp;
my $subst = '<a href="$1">$2</a>';
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