use strict; use warnings; hätte dir Suchen erspart ;)

Oder mal zum Testen deines Codes:
T:\>perl -cw t.pl
Scalar value @s[0] better written as $s[0] at t.pl line 14.
Scalar value @s[1] better written as $s[1] at t.pl line 15.
Scalar value @s[1] better written as $s[1] at t.pl line 24.
Global symbol "@ps" requires explicit package name at t.pl line 8.
Global symbol "@hiera" requires explicit package name at t.pl line 8.
Global symbol "@ps" requires explicit package name at t.pl line 17.
Global symbol "@ps" requires explicit package name at t.pl line 18.
Global symbol "@ps" requires explicit package name at t.pl line 19.
Global symbol "@hiera" requires explicit package name at t.pl line 26.
Global symbol "@hiera" requires explicit package name at t.pl line 28.
t.pl had compilation errors.

T:\>