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 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 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 a null pointer.  Otherwise it returns 0.

CONFORMING TO
       C99.

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

SEE ALSO
       mbsrtowcs(3), wcsrtombs(3)

COLOPHON
       This page is part of release 3.25 of the Linux man-pages project.  A description of the project,  and  information  about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



GNU                                                        2000-11-20                                                 MBSINIT(3)