StringCbLength function
Determines whether a string exceeds the specified length, in bytes.
StringCbLength is a replacement for the following functions:
Syntax
HRESULT StringCbLength( _In_ LPCTSTR psz, _In_ size_t cbMax, _Out_ size_t *pcb );
Parameters
- psz [in]
-
Type: LPCTSTR
The string whose length is to be checked.
- cbMax [in]
-
Type: size_t
The maximum number of bytes allowed in psz, including those used for the terminating null character. This value cannot exceed
STRSAFE_MAX_CCH * sizeof(TCHAR). - pcb [out]
-
Type: size_t*
The number of bytes in psz, excluding those used for the terminating null character. This value is valid only if pcb is not NULL and the function succeeds.
Return value
Type: HRESULT
This function can return one of the following values. It is strongly recommended that you use the SUCCEEDED and FAILED macros to test the return value of this function.
| Return code | Description |
|---|---|
|
The string at psz was not NULL, and the length of the string (including the terminating null character) is less than or equal to cbMax characters. |
|
The value in psz is NULL, cbMax is larger than |
Note that this function returns an HRESULT value, unlike the functions that it replaces.
Remarks
Compared to the functions it replaces, StringCbLength is an additional tool for proper buffer handling in your code. Poor buffer handling is implicated in many security issues that involve buffer overruns.
StringCbLength can be used in its generic form, or in its more specific forms. The data type of the string determines the form of this function that you should use.
| String Data Type | String Literal | Function |
|---|---|---|
| char | "string" | StringCbLengthA |
| TCHAR | TEXT("string") | StringCbLength |
| WCHAR | L"string" | StringCbLengthW |
Requirements
|
Minimum supported client |
Windows XP with SP2 [desktop apps | Windows Store apps] |
|---|---|
|
Minimum supported server |
Windows Server 2003 with SP1 [desktop apps | Windows Store apps] |
|
Header |
|
|
Unicode and ANSI names |
StringCbLengthW (Unicode) and StringCbLengthA (ANSI) |
See also