wcrtomb (3)
Leading comments
Copyright (c) Bruno Haible <haible@clisp.cons.org> %%%LICENSE_START(GPLv2+_DOC_ONEPARA) This is free documentation; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. %%%LICENSE_END References consulted: GNU glibc-2 source code and manual Dinkumware C library reference http://www.dinkumware.com/ OpenGroup's Single UNIX specificat...
NAME
wcrtomb - convert a wide character to a multibyte sequenceSYNOPSIS
#include <wchar.h> size_t wcrtomb(char *s, wchar_t wc, mbstate_t *ps);
DESCRIPTION
The main case for this function is when s is not NULL and wc is not a null wide character (Laq\0aq). In this case, the wcrtomb() function converts the wide character wc to its multibyte representation and stores it at the beginning of the character array pointed to by s. It updates the shift state *ps, and returns the length of said multibyte representation, that is, the number of bytes written at s.A different case is when s is not NULL, but wc is a null wide character (Laq\0aq). In this case, the wcrtomb() function stores at the character array pointed to by s the shift sequence needed to bring *ps back to the initial state, followed by a aq\0aq byte. It updates the shift state *ps (i.e., brings it into the initial state), and returns the length of the shift sequence plus one, that is, the number of bytes written at s.
A third case is when
s
is NULL.
In this case,
wc
is ignored,
and the function effectively returns
wcrtomb(buf, Laq\0aq, ps)
where
buf
is an internal anonymous buffer.
In all of the above cases, if ps is NULL, a static anonymous state known only to the wcrtomb() function is used instead.
RETURN VALUE
The wcrtomb() function returns the number of bytes that have been or would have been written to the byte array at s. If wc can not be represented as a multibyte sequence (according to the current locale), (size_t) -1 is returned, and errno set to EILSEQ.ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).| Interface | Attribute | Value |
| wcrtomb() | Thread safety | MT-Unsafe race:wcrtomb/!ps |
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99.NOTES
The behavior of wcrtomb() depends on the LC_CTYPE category of the current locale.Passing NULL as ps is not multithread safe.