NAME
wcsrtombs() — convert a wide-character string to a character string (restartable)
SYNOPSIS
#include <wchar.h>
size_t wcsrtombs(char *__restrict dst, const wchar_t **__restrict src,
size_t len, mbstate_t *__restrict ps);
DESCRIPTION
The
wcsrtombs()
function converts a sequence of wide-characters from the array indirectly
pointed to by
src
into a sequence of corresponding characters, beginning in the conversion state
described by the object pointed to by
ps.
If
dst
is not a null pointer, the converted characters are then stored into
the array pointed to by
dst.
Conversion continues up to and including a terminating null wide-character,
which is also stored. Conversion stops earlier in the following cases:
When a code is reached that does not correspond to a valid character.
When the next character would exceed the limit of
len
total bytes to be stored in the array pointed to by
dst
(and
dst
is not a null pointer).
Each conversion takes place as if by a call to the
wcrtomb()
function.
If
dst
is not a null pointer, the pointer object pointed to by
src
is assigned either a null pointer
(if conversion stopped due to reaching a terminating null wide-character)
or the address just past the last wide-character converted (if any).
If conversion stopped due to reaching a terminating null wide-character,
the resulting state described is the initial conversion state.
If
ps
is a null pointer, the
wcsrtombs()
function uses its own internal
mbstate_t
object, which is initialized
at program startup to the initial conversion state.
Otherwise, the
mbstate_t
object pointed to by
ps
is used to completely describe the current conversion state of
the associated character sequence.
The implementation will behave as if no function defined in this specification
calls
wcsrtombs().
APPLICATION USAGE
The prototype of this function is available to applications
if they are:
- a.
c99
conformant.
- b.
Compiled with
-D_XOPEN_SOURCE
macro with a value >=500.
- c.
Compiled with
-D_POSIX_C_SOURCE
macro with a value >= 200112.
EXTERNAL INFLUENCES
Environment Variables
The behavior of this function is affected by the
LC_CTYPE
category of the current locale.
RETURN VALUE
If conversion stops because a code is reached that does not correspond
to a valid character, an encoding error occurs.
In this case, the
wcsrtombs()
function stores the value of the macro
EILSEQ
in
errno
and returns
(size_t)-1;
the conversion state is undefined.
Otherwise, it returns the number of bytes in the resulting character sequence,
not including the terminating null (if any).
ERRORS
The
wcsrtombs()
function may fail if:
- EILSEQ
A wide-character code does not correspond to a valid character.
- EINVAL
ps
points to an object that contains an invalid conversion state.
AUTHOR
wcsrtombs()
was developed by HP and Mitsubishi Electric Corporation.
Printable version
