RtlStringCbVPrintfW - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers 
#ifndef _NTSTRSAFE_H_INCLUDED_
#ifndef NTSTRSAFE_LIB_IMPL
#ifndef NTSTRSAFE_NO_CB_FUNCTIONS

NTSTRSAFEDDI
    RtlStringCbVPrintfW(
            _Out_writes_bytes_(cbDest) _Always_(_Post_z_) NTSTRSAFE_PWSTR pszDest,
            _In_ size_t cbDest,
            _In_ _Printf_format_string_ NTSTRSAFE_PCWSTR pszFormat,
            _In_ va_list argList)
{
    NTSTATUS status;
    size_t cchDest = cbDest / sizeof(wchar_t);

    status = RtlStringValidateDestW(pszDest, cchDest, NTSTRSAFE_MAX_CCH);

    if (NT_SUCCESS(status))
    {
        status = RtlStringVPrintfWorkerW(pszDest,
                cchDest,
                NULL,
                pszFormat,
                argList);
    }
    else if (cchDest > 0)
    {
        *pszDest = '\0';
    }

    return status;
}

#endif
#endif
#endif

View code on GitHub
// ntstrsafe.h

NTSTRSAFEDDI RtlStringCbVPrintfW(
  [out] NTSTRSAFE_PWSTR  pszDest,
  [in]  size_t           cbDest,
  [in]  NTSTRSAFE_PCWSTR pszFormat,
  [in]  va_list          argList
);
View the official Windows Driver Kit DDI reference

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Windows Driver Kit DDI reference (nf-ntstrsafe-rtlstringcbvprintfw)

RtlStringCbVPrintfW function

Description

The RtlStringCbVPrintfW and RtlStringCbVPrintfA functions create a byte-counted text string, with formatting that is based on supplied formatting information.

Parameters

pszDest [out]

A pointer to a caller-supplied buffer that receives a formatted, null-terminated string. The function creates this string from both the formatting string that is supplied by pszFormat and the arguments supplied by argList.

cbDest [in]

The size of the destination buffer, in bytes. The buffer must be large enough to contain the formatted string plus the terminating null character.

For Unicode strings, the maximum number of bytes is NTSTRSAFE_MAX_CCH * sizeof(WCHAR).

For ANSI strings, the maximum number of bytes is NTSTRSAFE_MAX_CCH * sizeof(char).

pszFormat [in]

A pointer to a null-terminated text string that contains printf-styled formatting directives.

argList [in]

A va_list-typed argument list. Arguments contained in the argument list will be interpreted by using the formatting string that is supplied by pszFormat.

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.

Return code Description
STATUS_SUCCESS This success status means source data was present, the output string was created without truncation, and the resultant destination buffer is null-terminated.
STATUS_BUFFER_OVERFLOW This warning status means the operation did not complete due to insufficient space in the destination buffer. The destination buffer contains a truncated version of the created string.
STATUS_INVALID_PARAMETER This error status means the function received an invalid input parameter. For more information, see the following paragraph.

The function returns the STATUS_INVALID_PARAMETER value when:

* 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.

Remarks

RtlStringCbVPrintfW and RtlStringCbVPrintfA should be used instead of the following functions:

All of these functions accept a format string, along with a set of arguments in a va_list-typed argument list, and return a formatted string. The size, in bytes, of the destination buffer is provided to RtlStringCbVPrintfW and RtlStringCbVPrintfA to ensure that they do not write past the end of the buffer.

For more information about va_list-typed argument lists, see the Microsoft Windows SDK documentation.

Use RtlStringCbVPrintfW to handle Unicode strings and RtlStringCbVPrintfA to handle ANSI strings. The form you use depends on your data, as shown in the following table.

String data type String literal Function
WCHAR L"string" RtlStringCbVPrintfW
char "string" RtlStringCbVPrintfA

If pszDest and pszFormat point to overlapping strings or if any argument strings overlap, the behavior of the function is undefined..

Neither pszFormat nor pszDest should be NULL. If you need to handle NULL string pointer values, use RtlStringCbVPrintfEx.

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

See also

RtlStringCbPrintf

RtlStringCbVPrintfEx

RtlStringCchVPrintf

View the official Windows Driver Kit DDI reference

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