NAME

mbsnrtowcs, mbsnrtowcs_l, mbsrtowcs, mbsrtowcs_l - convert a character string to a wide-character string (restartable)

SYNOPSIS

#include <wchar.h>
size_t mbsnrtowcs(wchar_t *restrict dst, const char **restrict src,


     size_t nms, size_t len, mbstate_t *restrict ps);

size_t mbsrtowcs(wchar_t *restrict dst, const char **restrict src,


     size_t len, mbstate_t *restrict ps);

#include <wchar.h>
#include <xlocale.h>
size_t mbsnrtowcs_l(wchar_t *restrict dst, const char **restrict src,


     size_t nms, size_t len, mbstate_t *restrict ps, locale_t loc);

size_t mbsrtowcs_l(wchar_t *restrict dst, const char **restrict src,


     size_t len, mbstate_t *restrict ps, locale_t loc);

DESCRIPTION

These function converts a sequence of characters, beginning in the conversion state described by the object pointed to by ps, from the array indirectly pointed to by src into a sequence of corresponding wide-characters. If dst is not a null pointer, the converted characters are stored into the array pointed to by dst. Conversion continues up to and including a terminating null character, which is also stored. Conversion stops early in either of the following cases:

o: When a sequence of bytes is encountered that does not form a valid character.

o: When len codes have been stored into the array pointed to by dst (and dst is not a null pointer).

Each conversion takes place as if by a call to the mbrtowc() 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 character) or the address just past the last character converted (if any). If conversion stopped due to reaching a terminating null character, and if dst is not a null pointer, the resulting state described is the initial conversion state.

If ps is a null pointer, these functions uses their 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 system will behave as if no function defined in the Reference Manual calls any of these functions.

The function mbsnrtowcs() behaves identically to mbsrtowcs(), except the conversion stops after reading nms bytes from the buffer pointed to by src.

The behavior of mbnrtowcs() and mbsrtowcs() functions are affected by the LC_CTYPE category of the current locale. See environ(7). The functions mbsrtowcs_l() and mbsnrtowcs_l() behave identically to mbsrtowcs() and mbsnrtowcs(), except that instead of using the current locale, they use the locale specified by loc.

RETURN VALUES

If the input conversion encounters a sequence of bytes that do not form a valid character, an encoding error occurs. In this case, these functions store the value of the macro EILSEQ in errno and return (size_t)−1; the conversion state is undefined. Otherwise, they return the number of characters successfully converted, not including the terminating null (if any).

ERRORS

These functions may fail if:

EINVAL

The ps argument points to an object that contains an invalid conversion state.

EILSEQ

Invalid character sequence is detected.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	See below.
MT-Level	See below.

The mbsnrtowcs() and mbsrtowcs() functions are Standard. The mbsnrtowcs_l() and mbsrtowcs_l() functions are Uncommitted.

If ps is not a null pointer, these functions use the mbstate_t object pointed to by ps and can be used safely in multithreaded applications, otherwise they use an internal mbstate_t object and are Unsafe in multithreaded applications.