vswprintf_s.c File Reference

#include "safe_str_lib.h"

Include dependency graph for vswprintf_s.c:

Macros
#define	__STDC_WANT_LIB_EXT1__   1

Functions
EXPORT int	vswprintf_s (wchar_t *restrict dest, rsize_t dmax, const wchar_t *restrict fmt, va_list ap)
	The vswprintf_s function composes a wide string with same test that would be printed if format was used on wprintf. More...

Macro Definition Documentation

__STDC_WANT_LIB_EXT1__

#define __STDC_WANT_LIB_EXT1__   1

Function Documentation

vswprintf_s()

EXPORT int vswprintf_s	(	wchar_t *restrict	dest,
		rsize_t	dmax,
		const wchar_t *restrict	fmt,
		va_list	ap
	)

The vswprintf_s function composes a wide string with same test that would be printed if format was used on wprintf.

Instead of being printed, the content is stored in dest. With SAFECLIB_STR_NULL_SLACK defined all elements following the terminating null character (if any) written by vswprintf_s in the array of dmax wide characters pointed to by dest are nulled when vswprintf_s returns.

Remarks

SPECIFIED IN

• C11 standard (ISO/IEC 9899:2011): K.3.9.1.9 The vswprintf_s function (p: 634-635) http://en.cppreference.com/w/c/io/vfwprintf

Parameters

[out]	dest	pointer to wide string that will be written into.
[in]	dmax	restricted maximum length of dest
[in]	fmt	format-control wide string.
[in]	ap	optional arguments

Precondition

Neither dest nor fmt shall be a null pointer.

dmax shall not be greater than RSIZE_MAX_WSTR.

dmax shall not equal zero.

dmax shall be greater than wcsnlen_s(dest, dmax).

fmt shall not contain the conversion specifier n

None of the arguments corresponding to s is a null pointer (not yet)

No encoding error shall occur.

Note

C11 uses RSIZE_MAX, not RSIZE_MAX_WSTR.

Returns

If no runtime-constraint violation occurred, the vswprintf_s function returns the number of wide characters written in the array, not counting the terminating null wide character. If an encoding error occurred or if n or more wide characters are requested to be written, vswprintf_s returns a negative value. If any other runtime-constraint violation occurred, vswprintf_s returns zero.

If the buffer dest is too small for the formatted text, including the terminating null, then the buffer is set to an empty string by placing a null wide character at dest[0], and the invalid parameter handler is invoked. Unlike vsnprintf, vswprintf_s guarantees that the buffer will be null-terminated unless the buffer size is zero.

errno: ESNULLP when dest/fmt is NULL pointer ESZEROL when dmax = 0 ESLEMAX when dmax > RSIZE_MAX_WSTR ESNOSPC when return value exceeds dmax EINVAL when fmt contains n EINVAL or EOVERFLOW if returned by vswprintf

Return values

-1	if an encoding error occurred or if n or more wide characters are requested to be written.
0	on some other error.

See also

sprintf_s(), vsnprintf_s()