MBRTOWC(3) | FreeBSD Library Functions Manual | MBRTOWC(3) |
NAME
mbrtowc, mbrtoc16, mbrtoc32 — 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 pc, const char * restrict s, size_t n, mbstate_t * restrict ps);
#include < uchar.h>
size_t
mbrtoc16( char16_t * restrict pc, const char * restrict s, size_t n, mbstate_t * restrict ps);
size_t
mbrtoc32( char32_t * restrict pc, const char * restrict s, size_t n, mbstate_t * restrict ps);
DESCRIPTION
The mbrtowc(), mbrtoc16() and mbrtoc32() functions inspect 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 pc is not NULL, the wide character which is represented by s is stored in the wchar_t, char16_t or char32_t it points to.If s is NULL, these functions behave as if pc was NULL, s was an empty string (“”) and n was 1.
The mbstate_t argument, ps, is used to keep track of the shift state. If it is NULL, these functions use an internal, static mbstate_t object, which is initialized to the initial conversion state at program startup.
As a single char16_t is not large enough to represent certain multibyte characters, the mbrtoc16() function may need to be invoked multiple times to convert a single multibyte character sequence.
RETURN VALUES
The mbrtowc(), mbrtoc16() and mbrtoc32() functions return:- 0
-
The next
n or fewer bytes represent the null wide character (
L'\0'
). - >0
- The next n or fewer bytes represent a valid character, these functions return the number of bytes used to complete the multibyte character.
- ( size_t)-1
- An encoding error has occurred. The next n or fewer bytes do not contribute to a valid multibyte character.
- ( size_t)-2
- The next n contribute to, but do not complete, a valid multibyte character sequence, and all n bytes have been processed.
The mbrtoc16() function also returns:
- ( size_t)-3
- The next character resulting from a previous call has been stored. No bytes from the input have been consumed.
ERRORS
The mbrtowc(), mbrtoc16() and mbrtoc32() functions will fail if:- [ EILSEQ]
- An invalid multibyte sequence was detected.
- [ EINVAL]
- The conversion state is invalid.
STANDARDS
The mbrtowc(), mbrtoc16() and mbrtoc32() functions conform to ISO/IEC 9899:2011 (“ISO C11”).May 21, 2013 | FreeBSD |