use strict;
use warnings;
my $file = "/path/to/config/config.txt";
my(%by_name, %by_fruit, %by_path);
for my $data (parse_file($file)) {
  # Create lookups for each data item returned.
  # We assume any data can appear more than once, so we
  # store an array(ref) of data structures for each match.
  push @{ $by_name{$data->{name}} }, $data;
  push @{ $by_fruit{$data->{fruit}} }, $data;
  push @{ $by_path{$data->{path}} }, $data;
}

# now let us show all the paths by fruit:
for my $fruit (sort keys %by_fruit) {
  print "Fruit $fruit:\n";
  # $by_fruit{$fruit} is now an arrayref of data structures
  # matching 'fruit eq $fruit'
  for my $data (@{ $by_fruit{$fruit} }) {
    print "  $data->{path}\n";
  }
}

# Return a list of data structures, one for each line of
# the specified file that contains data.
# Blank lines and comment lines are ignored.
sub parse_file {
  my $file = shift;
  open(my $fh, "<", $file) or die "Can't open < $file: $!";
  return map {
    if (/^#/ || /^\s*$/) {
      ();  # no data on this line
    } else {
      my($name, $fruit, $path) = split ' ', $_;
      # Return a data structure as a hash reference
      {
        name => $name,
        fruit => $fruit,
        path => $path,
      };
    }
  } <$fh>;
  # Note that $file is automatically closed when the variable
  # goes out of scope, on return from this function.
}