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



NAME
       mbtowc - convert a multibyte sequence to a wide character

SYNOPSIS
       #include <stdlib.h>

       int mbtowc(wchar_t *pwc, const char *s, size_t n);

DESCRIPTION
       The  main case for this function is when s is not NULL and pwc is not NULL.  In this case, the mbtowc() function inspects
       at most n bytes of the multibyte string starting at s, extracts the next complete multibyte character, converts it  to  a
       wide  character  and stores it at *pwc.  It updates an internal shift state only known to the mbtowc function.  If s does
       not point to a '\0' byte, it returns the number of bytes that were consumed from s, otherwise it returns 0.

       If the n bytes starting at s do not contain a complete multibyte character, or  if  they  contain  an  invalid  multibyte
       sequence, mbtowc() returns -1.  This can happen even if n >= MB_CUR_MAX, if the multibyte string contains redundant shift
       sequences.

       A different case is when s is not NULL but pwc is NULL.  In this case the mbtowc() function behaves as above, except that
       it does not store the converted wide character in memory.

       A third case is when s is NULL.  In this case, pwc and n are ignored.  The mbtowc() function resets the shift state, only
       known to this function, to the initial state, and returns nonzero if the encoding has nontrivial shift state, or zero  if
       the encoding is stateless.

RETURN VALUE
       If  s  is  not NULL, the mbtowc() function returns the number of consumed bytes starting at s, or 0 if s points to a null
       byte, or -1 upon failure.

       If s is NULL, the mbtowc() function returns nonzero if the encoding has nontrivial shift state, or zero if  the  encoding
       is stateless.

CONFORMING TO
       C99.

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

       This function is not multithread safe.  The function mbrtowc(3) provides a better interface to the same functionality.

SEE ALSO
       MB_CUR_MAX(3), mbrtowc(3), mbstowcs(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                                                        2001-07-04                                                  MBTOWC(3)