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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 codeDescription
S_OK

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.

STRSAFE_E_INVALID_PARAMETER

The value in psz is NULL, cbMax is larger than STRSAFE_MAX_CCH * sizeof(TCHAR), or psz is longer than cbMax.

 

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 TypeString LiteralFunction
char"string"StringCbLengthA
TCHARTEXT("string")StringCbLength
WCHARL"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

Strsafe.h

Unicode and ANSI names

StringCbLengthW (Unicode) and StringCbLengthA (ANSI)

See also

StringCchLength

 

 

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