use strict;
my $str = '1)lorum ipsum www.goal.com
2)lorum ipsum http://www.goal.com
3)lorum ipsum https://www.goal.com
4)lorum ipsum https://www.goal.com/1234
5)lorum ipsum www.';
my $regex = qr/(http[s]?:\/\/)?www\.(?=.+)/mp;
my $subst = '';
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