How do I load a file into a Perl hash?

department=value1
location=valueA
location=valueB
department=value2

use File::Slurp;
use Data::Dumper;
my %hash = map {
   s/#.*//;
   s/^s+//;
   s/s+$//;
   m/(.*?)s*=s*(.*)/;
} read_file($file);
print Dumper(%hash);

$VAR1 = {
          'location' => 'valueB',
          'department' => 'value2'
        };

$VAR1 = {
          'location' => 'valueA,valueB',
          'department' => 'value1,value2'
        };

my %hash;
while (<FILE>)
{
   chomp;
   my ($key, $val) = split /=/;
   $hash{$key} .= exists $hash{$key} ? ",$val" : $val;
}

name:       Wally Jones
department: [foo, bar]
location:   [baz, biff]

use File::Slurp;
use YAML::XS;
use Data::Dumper;

print Dumper Load scalar read_file(shift);

$VAR1 = {
          'department' => [
                            'foo',
                            'bar'
                          ],
          'location' => [
                          'baz',
                          'biff'
                        ],
          'name' => 'Wally Jones'
        };