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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |
MBSINIT(3) Linux Programmer's Manual MBSINIT(3)
mbsinit - test for initial shift state
#include <wchar.h>
int mbsinit(const mbstate_t *ps);
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.
mbsinit() returns nonzero if *ps is an initial state, or if ps is
NULL. Otherwise, it returns 0.
For an explanation of the terms used in this section, see
attributes(7).
┌──────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├──────────┼───────────────┼─────────┤
│mbsinit() │ Thread safety │ MT-Safe │
└──────────┴───────────────┴─────────┘
POSIX.1-2001, POSIX.1-2008, C99.
The behavior of mbsinit() depends on the LC_CTYPE category of the
current locale.
mbrlen(3), mbrtowc(3), mbsrtowcs(3), wcrtomb(3), wcsrtombs(3)
This page is part of release 4.12 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/.
GNU 2016-10-08 MBSINIT(3)
Pages that refer to this page: mbrtowc(3), mbsnrtowcs(3), mbsrtowcs(3), wcrtomb(3), wcsnrtombs(3), wcsrtombs(3)