use strict;
my $str = 'https://www.reddit.com/r/RationalPsychonaut/comments/5m4rhv/a_satirical_blog_about_enlightenment_in_everyday/
https://www.reddit.com/r/swift/comments/5mriaj/i_just_released_a_swift_wrapper_for_the_llvm_api/
';
my $regex = qr/\/[^\/]*\/[^\/]*\/$/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