RtlStringCbCat

The RtlStringCbCatW and RtlStringCbCatA functions concatenate two byte-counted strings.

NTSTATUS
  RtlStringCbCatW(
    IN OUT LPWSTR  pszDest,
    IN size_t  cbDest,
    IN LPCWSTR  pszSrc,
    );

NTSTATUS
  RtlStringCbCatA(
    IN OUT LPSTR  pszDest,
    IN size_t  cbDest,
    IN LPCSTR  pszSrc,
    );

Parameters

pszDest

Caller-supplied pointer to a buffer which, on input, contains a NULL-terminated string to which pszSrc will be concatenated. On output, this is the destination buffer that contains the entire resultant string. The string at pszSrc is added to the end of the string at pszDest and terminated with a NULL character.

cbDest

Supplies the size of the destination buffer, in bytes.

For Unicode strings, the maximum number of bytes is STRSAFE_MAX_CCH * sizeof(char).

For ANSI strings, the maximum number of bytes is STRSAFE_MAX_CCH * sizeof(WCHAR).

pszSrc

Caller-supplied pointer to a NULL-terminated string. This string will be concatenated to the end of the string that is contained in the buffer at pszDest.

Return Value

The function returns one of the NTSTATUS values that are listed in the following table. For information about how to test NTSTATUS values, see Using NTSTATUS Values.

The STATUS_INVALID_PARAMETER return value means that one of the following occurred:

• The value in cbDest is larger than the maximum buffer size.
• The destination buffer was already full.
• A NULL pointer was present.
• The destination buffer length was zero, but a nonzero length source string was present.

Headers

Declared in ntstrsafe.h. Include ntstrsafe.h. Link to ntstrsafe.lib.

Comments

RtlStringCbCatW and RtlStringCbCatA should be used instead of the following functions:

• strcat
• wcscat

Because RtlStringCbCatW and RtlStringCbCatA receive the size of the destination buffer as input, they will not write past the end of the buffer.

Use RtlStringCbCatW to handle Unicode strings and RtlStringCbCatA to handle ANSI strings. The form to use is determined by your data as shown in the following table.

If pszSrc and pszDest point to strings that overlap, the behavior of the functions is undefined.

Neither pszSrc nor pszDest can be NULL. If you need to handle null string pointer values, use RtlStringCbCatNEx.

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

See Also

RtlStringCbCatEx, RtlStringCchCatEx, RtlStringCbCatNEx