mbsinit(3) — Linux manual page


MBSINIT(3)                Linux Programmer's Manual               MBSINIT(3)

NAME         top

       mbsinit - test for initial shift state

SYNOPSIS         top

       #include <wchar.h>

       int mbsinit(const mbstate_t *ps);

DESCRIPTION         top

       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;

       On Linux, the following works as well, but might generate compiler

           mbstate_t state = { 0 };

       The function mbsinit() tests whether *ps corresponds to an initial

RETURN VALUE         top

       mbsinit() returns nonzero if *ps is an initial state, or if ps is
       NULL.  Otherwise, it returns 0.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface Attribute     Value   │
       │mbsinit() │ Thread safety │ MT-Safe │

CONFORMING TO         top

       POSIX.1-2001, POSIX.1-2008, C99.

NOTES         top

       The behavior of mbsinit() depends on the LC_CTYPE category of the
       current locale.

SEE ALSO         top

       mbrlen(3), mbrtowc(3), mbsrtowcs(3), wcrtomb(3), wcsrtombs(3)

COLOPHON         top

       This page is part of release 5.08 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

GNU                              2016-10-08                       MBSINIT(3)

Pages that refer to this page: mbrtowc(3)mbsnrtowcs(3)mbsrtowcs(3)wcrtomb(3)wcsnrtombs(3)wcsrtombs(3)