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WCSRTOMBS(3)               Linux Programmer's Manual              WCSRTOMBS(3)
NAME
       wcsrtombs - convert a wide-character string to a multibyte string
SYNOPSIS
       #include <wchar.h>
       size_t wcsrtombs(char *dest, const wchar_t **src,
                        size_t len, mbstate_t *ps);
DESCRIPTION
       If dest is not NULL, the wcsrtombs() function converts the wide-charac-
       ter string *src to a multibyte string starting at dest.   At  most  len
       bytes  are  written to dest.  The shift state *ps is updated.  The con-
       version is effectively performed by  repeatedly  calling  wcrtomb(dest,
       *src, ps), as long as this call succeeds, and then incrementing dest by
       the number of bytes written and *src by one.  The conversion  can  stop
       for three reasons:
       1. A wide character has been encountered that can not be represented as
          a multibyte sequence (according to the  current  locale).   In  this
          case,   *src  is  left  pointing  to  the  invalid  wide  character,
          (size_t) -1 is returned, and errno is set to EILSEQ.
       2. The length limit forces a stop.  In this case, *src is left pointing
          to  the next wide character to be converted, and the number of bytes
          written to dest is returned.
       3. The wide-character string has been completely  converted,  including
          the  terminating  null  wide  character  (L'\0'), which has the side
          effect of bringing back *ps to the initial  state.   In  this  case,
          *src  is  set  to  NULL,  and  the  number of bytes written to dest,
          excluding the terminating null byte ('\0'), is returned.
       If dest is NULL, len is ignored, and the conversion proceeds as  above,
       except that the converted bytes are not written out to memory, and that
       no length limit exists.
       In both of the above cases, if ps is NULL,  a  static  anonymous  state
       known only to the wcsrtombs() function is used instead.
       The programmer must ensure that there is room for at least len bytes at
       dest.
RETURN VALUE
       The wcsrtombs() function returns the number of bytes that make  up  the
       converted  part  of  multibyte  sequence, not including the terminating
       null byte.  If a wide character was encountered which could not be con-
       verted, (size_t) -1 is returned, and errno set to EILSEQ.
ATTRIBUTES
       For   an   explanation   of   the  terms  used  in  this  section,  see
       attributes(7).
       +------------+---------------+------------------------------+
       |Interface   | Attribute     | Value                        |
       +------------+---------------+------------------------------+
       |wcsrtombs() | Thread safety | MT-Unsafe race:wcsrtombs/!ps |
       +------------+---------------+------------------------------+
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008, C99.
NOTES
       The behavior of wcsrtombs() depends on the  LC_CTYPE  category  of  the
       current locale.
       Passing NULL as ps is not multithread safe.
SEE ALSO
       iconv(3), mbsinit(3), wcrtomb(3), wcsnrtombs(3), wcstombs(3)
COLOPHON
       This  page  is  part of release 4.15 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                               2017-09-15                      WCSRTOMBS(3)