function country_group_code in ISBN Field 6

3 calls to country_group_code()

canonical_ISBN in ./isbn.inc

country_group_name in ./isbn.inc

is_assigned in ./isbn.inc

File

./isbn.inc, line 145

Code

function country_group_code($isbn_proto) {
  global $country_group_partition;
  $isbn_proto = ISN_clean($isbn_proto);
  $cglen = prefix_length_from_map($isbn_proto, $country_group_partition);
  return substr($isbn_proto, 0, $cglen);
}