use strict;
my $str = 'Sample text for testing:
abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
0123456789 _+-.,!@#$%^&*();\\/|<>"\'
12345 -98.7 3.141 .6180 \\9,000 +42
555.123.4567 +1-(800)-555-2468
foo@demo.net bar.ba@test.co.uk
www.demo.com http://foo.co\\.uk/
http://regexr.com/foo.html?q=bar
https://mediatemple.net||Test ';
my $regex = qr/([^|]+$)/mp;
my $subst = '$1';
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