MBSINIT
Section: Linux Programmer's Manual (3)
Updated: 2016-10-08
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NAME
mbsinit - test for initial shift state
SYNOPSIS
#include <wchar.h>
int mbsinit(const mbstate_t *ps);
DESCRIPTION
Character conversion between the multibyte representation and the wide
character representation uses conversion state, of type
mbstate_t.
Conversion of a string uses a finite-state machine; when it is interrupted
after the complete conversion of a number of characters, it may need to
save a state for processing the remaining characters.
Such a conversion
state is needed for the sake of encodings such as ISO-2022 and UTF-7.
The initial state is the state at the beginning of conversion of a string.
There are two kinds of state: the one used by multibyte to wide character
conversion functions, such as
mbsrtowcs(3),
and the one used by wide
character to multibyte conversion functions, such as
wcsrtombs(3),
but they both fit in a
mbstate_t,
and they both have the same
representation for an initial state.
For 8-bit encodings, all states are equivalent to the initial state.
For multibyte encodings like UTF-8, EUC-*, BIG5 or SJIS, the wide character
to multibyte conversion functions never produce non-initial states, but the
multibyte to wide-character conversion functions like
mbrtowc(3)
do
produce non-initial states when interrupted in the middle of a character.
One possible way to create an
mbstate_t
in initial state is to set it to zero:
mbstate_t state;
memset(&state,0,sizeof(mbstate_t));
On Linux, the following works as well, but might generate compiler warnings:
mbstate_t state = { 0 };
The function
mbsinit()
tests whether
*ps
corresponds to an
initial state.
RETURN VALUE
mbsinit()
returns nonzero if
*ps
is an initial state, or if
ps
is NULL.
Otherwise, it returns 0.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
| Interface | Attribute | Value
|
|
mbsinit()
| Thread safety | MT-Safe
|
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99.
NOTES
The behavior of
mbsinit()
depends on the
LC_CTYPE
category of the
current locale.
SEE ALSO
mbrlen(3),
mbrtowc(3),
mbsrtowcs(3),
wcrtomb(3),
wcsrtombs(3)
COLOPHON
This page is part of release 4.13 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/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ATTRIBUTES
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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