mbtowc — convert a multibyte sequence to a wide character
#include <stdlib.h>
int
mbtowc( |
wchar_t *pwc, |
const char *s, | |
size_t n) ; |
The main case for this function is when s
is not NULL and pwc
is not NULL. In this case,
the mbtowc
() function inspects
at most n
bytes of
the multibyte string starting at s
, extracts the next complete
multibyte character, converts it to a wide character and
stores it at *pwc
. It
updates an internal shift state known only to the
mbtowc
() function. If
s
does not point to a
null byte ('\0'), it returns the number of bytes that were
consumed from s
,
otherwise it returns 0.
If the n
bytes
starting at s
do not
contain a complete multibyte character, or if they contain an
invalid multibyte sequence, mbtowc
() returns −1. This can happen
even if n
>=
MB_CUR_MAX
, if the multibyte
string contains redundant shift sequences.
A different case is when s
is not NULL but pwc
is NULL. In this case, the
mbtowc
() function behaves as
above, except that it does not store the converted wide
character in memory.
A third case is when s
is NULL. In this case,
pwc
and n
are ignored. The mbtowc
() function resets the shift state,
only known to this function, to the initial state, and
returns nonzero if the encoding has nontrivial shift state,
or zero if the encoding is stateless.
If s
is not NULL,
the mbtowc
() function returns
the number of consumed bytes starting at s
, or 0 if s
points to a null byte, or
−1 upon failure.
If s
is NULL, the
mbtowc
() function returns
nonzero if the encoding has nontrivial shift state, or zero
if the encoding is stateless.
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
mbtowc () |
Thread safety | MT-Unsafe race |
The behavior of mbtowc
()
depends on the LC_CTYPE
category of the current locale.
This function is not multithread safe. The function mbrtowc(3) provides a better interface to the same functionality.
This page is part of release 4.07 of the Linux man-pages
project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
Copyright (c) Bruno Haible <haibleclisp.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 specification http://www.UNIX-systems.org/online.html ISO/IEC 9899:1999 |