mbsrtowcs — convert a multibyte string to a wide-character string
#include <wchar.h>
size_t mbsrtowcs( |
wchar_t * | dest, |
| const char ** | src, | |
| size_t | len, | |
| mbstate_t * | ps); |
If dest is not a
NULL pointer, the mbsrtowcs()
function converts the multibyte string *src to a wide-character
string starting at dest. At most len wide characters are written
to dest. The shift
state *ps is
updated. The conversion is effectively performed by
repeatedly calling mbrtowc(dest,
*src, n, ps) where n is some positive number, as
long as this call succeeds, and then incrementing dest by one and *src by the number of bytes
consumed. The conversion can stop for three reasons:
1. An invalid multibyte sequence has been encountered. In
this case *src is
left pointing to the invalid multibyte sequence, (size_t)(−1) is
returned, and errno is set to
EILSEQ.
2. len non-L'\0'
wide characters have been stored at dest. In this case *src is left pointing to the
next multibyte sequence to be converted, and the number of
wide characters written to dest is returned.
3. The multibyte string has been completely converted,
including the terminating '\0' (which has the side effect of
bringing back *ps
to the initial state). In this case *src is set to NULL, and the
number of wide characters written to dest, excluding the terminating
L'\0' character, is returned.
If dest is NULL,
len is ignored, and
the conversion proceeds as above, except that the converted
wide characters are not written out to memory, and that no
length limit exists.
In both of the above cases, if ps is a NULL pointer, a static
anonymous state only known to the mbsrtowcs function is used
instead.
The programmer must ensure that there is room for at least
len wide characters
at dest.
The mbsrtowcs() function
returns the number of wide characters that make up the
converted part of the wide-character string, not including
the terminating null wide character. If an invalid multibyte
sequence was encountered, (size_t)(−1) is
returned, and errno set to
EILSEQ.
The behavior of mbsrtowcs()
depends on the LC_CTYPE
category of the current locale.
Passing NULL as ps
is not multi-thread safe.
iconv(3), mbsnrtowcs(3), mbstowcs(3)
|
Copyright (c) Bruno Haible <haible@clisp.cons.org> 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. 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 |