my %ex = (
    "\n" . 'regexp'   => sub { s/.// },
    "\n" . 'regexp/s' => sub { s/.//s },
    "\n" . 'chop'     => sub { $_ = reverse; chop; $_ = reverse; },
    "\n" . 'substr1'  => sub { substr($_,0,1) = '' },
    "\n" . 'substr2'  => sub { $_ = substr($_,1) },
);

for (sort keys %ex) {
    $ex{$_}->();
    print "[$_]\n";
}

__END__
[chop]
[
egexp]
[regexp/s]
[substr1]
[substr2]