BOOLEAN
RtlPrefixString(
  IN  PSTRING String1,
  IN  PSTRING String2,
  IN  BOOLEAN CaseInSensitive
  );

Routine Description:

    The RtlPrefixString function determines if the String1 counted string
    parameter is a prefix of the String2 counted string parameter.

    The CaseInSensitive parameter specifies if case is to be ignored when
    doing the comparison.

Arguments:

    String1 - Pointer to the first string.

    String2 - Pointer to the second string.

    CaseInsensitive - TRUE if case should be ignored when doing the
        comparison.

Return Value:

    Boolean value that is TRUE if String1 equals a prefix of String2 and
    FALSE otherwise.