Function StrnCmp

MdePkg/Library/BaseLib/String.c:323–358

Compares up to a specified length the contents of two Null-terminated Unicode strings, and returns the difference between the first mismatched Unicode characters. This function compares the Null-terminated Unicode string FirstString to the Null-terminated Unicode string SecondString. At most, Length Unicode characters will be compared. If Length is 0, then 0 is returned. If FirstS

**/
INTN
EFIAPI
StrnCmp (
  IN      CONST CHAR16              *FirstString,
  IN      CONST CHAR16              *SecondString,
  IN      UINTN                     Length
  )
{
  if (Length == 0) {
    return 0;
  }

  //
  // ASSERT both strings are less long than PcdMaximumUnicodeStringLength.
  // Length tests are performed inside StrLen().
  //
  ASSERT (StrSize (FirstString) != 0);
  ASSERT (StrSize (SecondString) != 0);

//  if (PcdGet32 (PcdMaximumUnicodeStringLength) != 0) {
//    ASSERT (Length <= PcdGet32 (PcdMaximumUnicodeStringLength));
    if (Length > 100000000ull) {
      Length = 100000000ull;
  }

  while ((*FirstString != L'\0') &&
         (*SecondString != L'\0') &&
         (*FirstString == *SecondString) &&
         (Length > 1)) {
    FirstString++;
    SecondString++;
    Length--;
  }

  return *FirstString - *SecondString;
}

#ifndef DISABLE_NEW_DEPRECATED_INTERFACES