use strict;
use warnings;
use Data::Dumper;

open SCRIPT, "script.pl" or die "Can't open file: $!";

our $hash_declaration='';
our %some_hash;

while (<SCRIPT>) {
   # Find the declaration
   next unless /\%some_hash/;
   $hash_declaration = $_;
   # Now pop out and do another while loop
   last;
}
while (<SCRIPT>) {
   # Keep appending until we reach a semi-colon
   $hash_declaration .= $_;
   eval $hash_declaration;
   last unless $@;
}
close(SCRIPT);

print Data::Dumper->Dumper(\%some_hash);