Function StrnLenS

MdePkg/Library/BaseLib/SafeString.c:120–152

Returns the length of a Null-terminated Unicode string. This function is similar as strlen_s defined in C11. If String is not aligned on a 16-bit boundary, then ASSERT(). @param String A pointer to a Null-terminated Unicode string. @param MaxSize The maximum number of Destination Unicode char, including terminating null char. Slice: NOT including @r

  StrnLenS(string, 9) = 6;
**/
UINTN
EFIAPI
StrnLenS (
  IN CONST CHAR16              *String,
  IN UINTN                     MaxSize
  )
{
  UINTN                             Length;

  ASSERT (((UINTN) String & BIT0) == 0);

  //
  // If String is a null pointer, then the StrnLenS function returns zero.
  //
  if (String == NULL) {
    return 0;
  }

  //
  // Otherwise, the StrnLenS function returns the number of characters that precede the
  // terminating null character. If there is no null character in the first MaxSize characters of
  // String then StrnLenS returns MaxSize. At most the first MaxSize characters of String shall
  // be accessed by StrnLenS.
  //
  Length = 0;
  while (String[Length] != 0) {
    if (Length >= MaxSize - 1) {
      return MaxSize;
    }
    Length++;
  }
  return Length;
}

/**
  Returns the size of a Null-terminated Unicode string in bytes, including the