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MBSRTOWCS(3P)              POSIX Programmer's Manual             MBSRTOWCS(3P)
PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       mbsnrtowcs, mbsrtowcs -- convert a character string to a wide-character
       string (restartable)
SYNOPSIS
       #include <wchar.h>
       size_t mbsnrtowcs(wchar_t *restrict dst, const char **restrict src,
           size_t nmc, size_t len, mbstate_t *restrict ps);
       size_t mbsrtowcs(wchar_t *restrict dst, const char **restrict src,
           size_t len, mbstate_t *restrict ps);
DESCRIPTION
       For  mbsrtowcs(): The functionality described on this reference page is
       aligned with the ISO C standard. Any conflict between the  requirements
       described  here and the ISO C standard is unintentional. This volume of
       POSIX.1-2008 defers to the ISO C standard.
       The mbsrtowcs() function shall convert a sequence of characters, begin-
       ning  in the conversion state described by the object pointed to by ps,
       from the array indirectly pointed to by src into a sequence  of  corre-
       sponding  wide  characters. If dst is not a null pointer, the converted
       characters shall be stored into the array pointed to by  dst.   Conver-
       sion  continues up to and including a terminating null character, which
       shall also be stored. Conversion shall stop early in either of the fol-
       lowing cases:
        *  A sequence of bytes is encountered that does not form a valid char-
           acter.
        *  len codes have been stored into the array pointed to  by  dst  (and
           dst is not a null pointer).
       Each conversion shall take place as if by a call to the mbrtowc() func-
       tion.
       If dst is not a null pointer, the pointer  object  pointed  to  by  src
       shall  be  assigned either a null pointer (if conversion stopped due to
       reaching a terminating null character) or the  address  just  past  the
       last  character converted (if any). If conversion stopped due to reach-
       ing a terminating null character, and if dst is not a null pointer, the
       resulting state described shall be the initial conversion state.
       If  ps  is  a  null pointer, the mbsrtowcs() function shall use its own
       internal mbstate_t object, which is initialized at program start-up  to
       the  initial  conversion state. Otherwise, the mbstate_t object pointed
       to by ps shall be used to completely describe  the  current  conversion
       state of the associated character sequence.
       The  mbsnrtowcs() function shall be equivalent to the mbsrtowcs() func-
       tion, except that the conversion of characters pointed  to  by  src  is
       limited to at most nmc bytes (the size of the input buffer).
       The behavior of these functions shall be affected by the LC_CTYPE cate-
       gory of the current locale.
       The implementation shall behave as if no function defined in this  vol-
       ume of POSIX.1-2008 calls these functions.
       The  mbsnrtowcs()  and mbsrtowcs() functions need not be thread-safe if
       called with a NULL ps argument.
       The mbsrtowcs() function shall not change the setting of errno if  suc-
       cessful.
RETURN VALUE
       If the input conversion encounters a sequence of bytes that do not form
       a valid character, an encoding error occurs. In this case, these  func-
       tions  shall  store  the value of the macro [EILSEQ] in errno and shall
       return (size_t)-1; the conversion state is undefined.  Otherwise, these
       functions shall return the number of characters successfully converted,
       not including the terminating null (if any).
ERRORS
       These functions shall fail if:
       EILSEQ An invalid character sequence is detected.
       These functions may fail if:
       EINVAL ps points to an  object  that  contains  an  invalid  conversion
              state.
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       None.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       iconv(), mbrtowc(), mbsinit()
       The Base Definitions volume of POSIX.1-2008, <wchar.h>
COPYRIGHT
       Portions  of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal  and  Electronics  Engineers,  Inc  and  The  Open Group.  (This is
       POSIX.1-2008 with the 2013 Technical Corrigendum  1  applied.)  In  the
       event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard
       is  the  referee document. The original Standard can be obtained online
       at http://www.unix.org/online.html .
       Any typographical or formatting errors that appear  in  this  page  are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors,  see  https://www.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                        MBSRTOWCS(3P)