BEGIN{($path = $0) =~ s[[\\/][^\\/]+$][];}
BEGIN{ use lib $path;}
##</code><code>##

>cat tmp.pl
#!/usr/bin/perl
use strict;
use warnings;
print "$0\n";

>chmod +x tmp.pl
>perl tmp.pl
tmp.pl
>perl ./tmp.pl
./tmp.pl
>perl /tmp/tmp.pl
/tmp/tmp.pl
>./tmp.pl
./tmp.pl
>tmp.pl
./tmp.pl
>