RtlUnicodeStringInit function (ntstrsafe.h)

Article
02/22/2024

The RtlUnicodeStringInit function initializes a UNICODE_STRING structure.

Syntax

NTSTRSAFEDDI RtlUnicodeStringInit(
  [out]          PUNICODE_STRING  DestinationString,
  [in, optional] NTSTRSAFE_PCWSTR pszSrc
);

Parameters

[out] DestinationString

A pointer to a UNICODE_STRING structure to be initialized. The pszSrc pointer is copied into the DestinationString parameter's UNICODE_STRING structure. The maximum number of characters in the string that pszSrc points to is NTSTRSAFE_UNICODE_STRING_MAX_CCH.

[in, optional] pszSrc

Optional. A pointer to a null-terminated string constant. This string pointer will be copied to the Buffer member of the UNICODE_STRING structure pointed to by the DestinationString parameter. This string pointer can be NULL.

Return value

RtlUnicodeStringInit returns one of the following NTSTATUS values.

Return code	Description
STATUS_SUCCESS	This success status means that source data was present, the string was copied without truncation, and the resultant destination buffer is null-terminated.
STATUS_INVALID_PARAMETER	This error status means that the function received an invalid input parameter. For more information, see the following list.

RtlUnicodeStringInit returns the STATUS_INVALID_PARAMETER value when one of the following occurs:

The length of the string that the pszSrc parameter points to is greater than NTSTRSAFE_UNICODE_STRING_MAX_CCH characters.
The DestinationString pointer is NULL, but the pszSrc pointer is not NULL.

For information about how to test NTSTATUS values, see Using NTSTATUS Values.

Remarks

The RtlUnicodeStringInit function does the following:

Sets the Length member of the UNICODE_STRING structure that is pointed to by the pszSrc parameter to the length, in bytes, of the string that the pszSrc parameter points to.
Sets the MaximumLength member of the UNICODE_STRING structure to the length, in bytes, of the string that the pszSrc parameter points to plus 2 bytes.
Sets the Buffer member of the UNICODE_STRING structure to the address that the pszSrc parameter specifies.

The DestinationString pointer should not be NULL. If you need to specify NULL DestinationString pointer values, use the RtlUnicodeStringInitEx function.

For more information about the safe string functions, see Using Safe String Functions.

Requirements

Requirement	Value
Minimum supported client	Available starting with Windows XP with Service Pack 1 (SP1).
Target Platform	Desktop
Header	ntstrsafe.h (include Ntstrsafe.h)
Library	Ntstrsafe.lib
IRQL	PASSIVE_LEVEL