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

my $content = <<'GROK';
inc_albums=albumvalue
inc_genres=genrevalue
inc_artists =artistvalue
inc_songs=songsvalue
inc_ratings=ratingsvalue
inc_year=yearvalue
GROK

{
my %inc = map { my ($v) = $content =~ /inc_$_=(.*?)\n/; $_ => $v }
              qw(albums genres artists songs ratings year);
print Dumper(\%inc);
}

{
my %inc = map { $_ => ($content =~ /inc_$_=(.*?)\n/)[0]; }
              qw(albums genres artists songs ratings year);
print Dumper(\%inc);
}

{
my %inc = map { $_ => ($content =~ /inc_$_=(.*?)\n/)[0] || undef }
              qw(albums genres artists songs ratings year);
print Dumper(\%inc);
}