unlink($0) or warn $!,$/,$^E,$/;

##</code><code>##

unlink($0) or warn $!,$/,$^E,$/;
__END__

##</code><code>##

BEGIN { unlink($0) or warn $!,$/,$^E,$/ }

##</code><code>##

Permission denied
The process cannot access the file because it is being used by another process