WCRTOMB(3)                (2019-03-06)                 WCRTOMB(3)

     NAME
          wcrtomb - convert a wide character to a multibyte sequence

     SYNOPSIS
          #include <wchar.h>

          size_t wcrtomb(char *s, wchar_t wc, mbstate_t *ps

     DESCRIPTION
          The main case for this function is when s is not NULL and wc
          is not a null wide character (Laq\0aq).  In this case, the
          wcrtomb() function converts the wide character wc to its
          multibyte representation and stores it at the beginning of
          the character array pointed to by s. It updates the shift
          state *ps, and returns the length of said multibyte repre-
          sentation, that is, the number of bytes written at s.

          A different case is when s is not NULL, but wc is a null
          wide character (Laq\0aq).  In this case, the wcrtomb() func-
          tion stores at the character array pointed to by s the shift
          sequence needed to bring *ps back to the initial state, fol-
          lowed by a aq\0aq byte.  It updates the shift state *ps (i.e.,
          brings it into the initial state), and returns the length of
          the shift sequence plus one, that is, the number of bytes
          written at s.

          A third case is when s is NULL.  In this case, wc is
          ignored, and the function effectively returns

              wcrtomb(buf, Laq\0aq, ps)

          where buf is an internal anonymous buffer.

          In all of the above cases, if ps is NULL, a static anonymous
          state known only to the wcrtomb() function is used instead.

     RETURN VALUE
          The wcrtomb() function returns the number of bytes that have
          been or would have been written to the byte array at s. If
          wc can not be represented as a multibyte sequence (according
          to the current locale), (size_t) -1 is returned, and errno
          set to EILSEQ.

     ATTRIBUTES
          For an explanation of the terms used in this section, see
          attributes(7).  allbox; lb lb lbw26 l l l.
          Interface Attribute Value T{ wcrtomb() T}   Thread
          safety  MT-Unsafe race:wcrtomb/!ps

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     WCRTOMB(3)                (2019-03-06)                 WCRTOMB(3)

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

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

          Passing NULL as ps is not multithread safe.

     SEE ALSO
          mbsinit(3), wcsrtombs(3)

     COLOPHON
          This page is part of release 5.10 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/.

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