1 unicode.inc backdrop_truncate_bytes($string, $len)

Truncates a UTF-8-encoded string safely to a number of bytes.

If the end position is in the middle of a UTF-8 sequence, it scans backwards until the beginning of the byte sequence.

Use this function whenever you want to chop off a string at an unsure location. On the other hand, if you're sure that you're splitting on a character boundary (e.g. after using strpos() or similar), you can safely use substr() instead.


$string: The string to truncate.

$len: An upper limit on the returned string length.

Return value

The truncated string.:


core/includes/unicode.inc, line 268
Provides Unicode-related conversions and operations.


function backdrop_truncate_bytes($string, $len) {
  if (strlen($string) <= $len) {
    return $string;
  if ((ord($string[$len]) < 0x80) || (ord($string[$len]) >= 0xC0)) {
    return substr($string, 0, $len);
  // Scan backwards to beginning of the byte sequence.
  while (--$len >= 0 && ord($string[$len]) >= 0x80 && ord($string[$len]) < 0xC0);

  return substr($string, 0, $len);