mbrtowc(3) [mojave man page]

MBRTOWC(3)						   BSD Library Functions Manual 						MBRTOWC(3)

NAME

     mbrtowc, mbrtowc_l -- convert a character to a wide-character code (restartable)

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <wchar.h>

     size_t
     mbrtowc(wchar_t *restrict pwc, const char *restrict s, size_t n, mbstate_t *restrict ps);

     #include <wchar.h>
     #include <xlocale.h>

     size_t
     mbrtowc_l(wchar_t *restrict pwc, const char *restrict s, size_t n, mbstate_t *restrict ps, locale_t loc);

DESCRIPTION

     The mbrtowc() function inspects at most n bytes, pointed to by s, to determine the number of bytes needed to complete the next multibyte
     character.  If a character can be completed, and pwc is not NULL, the wide character which is represented by s is stored in the wchar_t it
     points to.

     If s is NULL, mbrtowc() behaves as if pwc were NULL, s were an empty string (""), and n were 1.

     The mbstate_t argument, ps, is used to keep track of the shift state.  If it is NULL, mbrtowc() uses an internal, static mbstate_t object,
     which is initialized to the initial conversion state at program startup.

     While the mbrtowc() function uses the current locale, the mbrtowc_l() function may be passed a locale directly. See xlocale(3) for more
     information.

RETURN VALUES

     The mbrtowc() functions returns:

     0	     The next n or fewer bytes represent the null wide character (L'').

     >0      The next n or fewer bytes represent a valid character, mbrtowc() returns the number of bytes used to complete the multibyte charac-
	     ter.

     (size_t)-2
	     The next n contribute to, but do not complete, a valid multibyte character sequence, and all n bytes have been processed.

     (size_t)-1
	     An encoding error has occurred.  The next n or fewer bytes do not contribute to a valid multibyte character.

ERRORS

     The mbrtowc() function will fail if:

     [EILSEQ]		An invalid multibyte sequence was detected.

     [EINVAL]		The conversion state is invalid.

SEE ALSO

     mbtowc(3), multibyte(3), setlocale(3), wcrtomb(3), xlocale(3)

STANDARDS

     The mbrtowc() function conforms to ISO/IEC 9899:1999 (``ISO C99'').

BSD
								   April 8, 2004							       BSD

MBRTOWC(3)						   BSD Library Functions Manual 						MBRTOWC(3)

NAME

     mbrtowc -- converts a multibyte character to a wide character (restartable)

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <wchar.h>

     size_t
     mbrtowc(wchar_t * restrict pwc, const char * restrict s, size_t n, mbstate_t * restrict ps);

DESCRIPTION

     The mbrtowc() usually converts the multibyte character pointed to by s to a wide character, and stores the wide character to the wchar_t
     object pointed to by pwc if pwc is non-NULL and s points to a valid character.  The conversion happens in accordance with, and changes the
     conversion state described in the mbstate_t object pointed to by ps.  This function may examine at most n bytes of the array beginning from
     s.

     If s points to a valid character and the character corresponds to a nul wide character, then the mbrtowc() places the mbstate_t object
     pointed to by ps to an initial conversion state.

     Unlike mbtowc(3), the mbrtowc() may accept the byte sequence pointed to by s not forming a complete multibyte character but which may be part
     of a valid character.  In this case, this function will accept all such bytes and save them into the conversion state object pointed to by
     ps.  They will be used at subsequent calls of this function to restart the conversion suspended.

     The behaviour of mbrtowc() is affected by the LC_CTYPE category of the current locale.

     These are the special cases:

     s == NULL	   mbrtowc() sets the conversion state object pointed to by ps to an initial state and always returns 0.  Unlike mbtowc(3), the
		   value returned does not indicate whether the current encoding of the locale is state-dependent.

		   In this case, mbrtowc() ignores pwc and n, and is equivalent to the following call:

			 mbrtowc(NULL, "", 1, ps);

     pwc == NULL   The conversion from a multibyte character to a wide character has taken place and the conversion state may be affected, but the
		   resulting wide character is discarded.

     ps == NULL    mbrtowc() uses its own internal state object to keep the conversion state, instead of ps mentioned in this manual page.

		   Calling any other functions in Standard C Library (libc, -lc) never changes the internal state of mbrtowc(), which is initial-
		   ized at startup time of the program.

RETURN VALUES

     In the usual cases, mbrtowc() returns:

     0		   The next bytes pointed to by s form a nul character.

     positive	   If s points to a valid character, mbrtowc() returns the number of bytes in the character.

     (size_t)-2    s points to a byte sequence which possibly contains part of a valid multibyte character, but which is incomplete.  When n is at
		   least MB_CUR_MAX, this case can only occur if the array pointed to by s contains a redundant shift sequence.

     (size_t)-1    s points to an illegal byte sequence which does not form a valid multibyte character.  In this case, mbrtowc() sets errno to
		   indicate the error.

ERRORS

     mbrtowc() may cause an error in the following case:

     [EILSEQ]		s points to an invalid or incomplete multibyte character.

     [EINVAL]		ps points to an invalid or uninitialized mbstate_t object.

SEE ALSO

     mbrlen(3), mbtowc(3), setlocale(3)

STANDARDS

     The mbrtowc() function conforms to ISO/IEC 9899/AMD1:1995 (``ISO C90, Amendment 1'').  The restrict qualifier is added at ISO/IEC 9899:1999
     (``ISO C99'').

BSD
								 February 4, 2002							       BSD