$ perl -MO=Concise -e 'print <>'
7  <@> leave[t1] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
6     <@> print vK ->7
3        <0> pushmark s ->4
5        <1> readline[t1] lK/1 ->6
4           <$> gv(*ARGV) s ->5 *ARGV

##</code><code>##

package SafeReadline;
require Exporter;
@ISA = 'Exporter';
@EXPORT = 'readline';
sub import {
    my $pkg = shift;
    return unless @_;
    my $sym = shift;
    $pkg->export("CORE::GLOBAL", $sym, @_);
}
sub readline { ... }