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



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 represen‐
       tation 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 charac‐
       ters, it may need to save a state for processing the remaining characters.  Such a conver‐
       sion 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 representa‐
       tion for an initial state.

       For 8-bit encodings, all states are equivalent to the initial state.  For multibyte encod‐
       ings 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  charac‐
       ter.

       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
   Multithreading (see pthreads(7))
       The mbsinit() function is thread-safe.

CONFORMING TO
       C99.

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

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

COLOPHON
       This page is part of release 3.74 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 http://www.kernel.org/doc/man-pages/.



GNU                                         2014-03-18                                 MBSINIT(3)