reactos/sdk/lib/crt/string/wcstombs_s.c

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/*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS CRT
* PURPOSE: Implementation of mbstowcs_s
* FILE: lib/sdk/crt/string/wcstombs_s.c
* PROGRAMMER: Timo Kreuzer
*/
#include <precomp.h>
_Success_(return!=EINVAL)
_Check_return_wat_
_CRTIMP
errno_t
__cdecl
wcstombs_s(
_Out_opt_ size_t * pcchConverted,
_Out_writes_bytes_to_opt_(cjDstSize, *pcchConverted)
char * pmbstrDst,
_In_ size_t cjDstSize,
_In_z_ const wchar_t * pwszSrc,
_In_ size_t cjMaxCount)
{
size_t cchMax, cchConverted;
errno_t retval = 0;
/* Make sure, either we have a target buffer > 0 bytes, or no buffer */
if (!MSVCRT_CHECK_PMT( ((cjDstSize != 0) && (pmbstrDst != 0)) ||
((cjDstSize == 0) && (pmbstrDst == 0)) ))
{
_set_errno(EINVAL);
return EINVAL;
}
/* Check if we have a return value pointer */
if (pcchConverted)
{
/* Default to 0 bytes written */
*pcchConverted = 0;
}
if (!MSVCRT_CHECK_PMT((cjMaxCount == 0) || (pwszSrc != 0)))
{
_set_errno(EINVAL);
return EINVAL;
}
/* Check if there is anything to do */
if ((pmbstrDst == 0) && (pwszSrc == 0))
{
_set_errno(EINVAL);
return EINVAL;
}
/* Check if we have a wchar string */
if (pwszSrc)
{
/* Check if we also have a multibyte buffer */
if (pmbstrDst)
{
/* Calculate the maximum that we can write */
cchMax = (cjMaxCount < cjDstSize) ? cjMaxCount + 1 : cjDstSize;
/* Now do the conversion */
cchConverted = wcstombs(pmbstrDst, pwszSrc, cchMax);
/* Check if the buffer was not zero terminated */
if (cchConverted == cchMax)
{
/* Check if we reached the max size of the dest buffer */
if (cchConverted == cjDstSize)
{
/* Does the caller allow this? */
if (cjMaxCount != _TRUNCATE)
{
/* Not allowed, truncate to 0 length */
pmbstrDst[0] = L'\0';
/* Return error */
_set_errno(ERANGE);
return ERANGE;
}
/* Inform the caller about truncation */
retval = STRUNCATE;
}
/* zero teminate the buffer */
pmbstrDst[cchConverted - 1] = L'\0';
}
else
{
/* The buffer is zero terminated, count the terminating char */
cchConverted++;
}
}
else
{
/* Get the length of the string, plus 0 terminator */
cchConverted = wcsnlen(pwszSrc, cjMaxCount) + 1;
}
}
else
{
cchConverted = cjMaxCount + 1;
}
/* Check if we have a return value pointer */
if (pcchConverted)
{
/* Default to 0 bytes written */
*pcchConverted = cchConverted;
}
return retval;
}