NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

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

NAME         top

       mbtowc - convert a multibyte sequence to a wide character

SYNOPSIS         top

       #include <stdlib.h>

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

DESCRIPTION         top

       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 known only to the mbtowc()
       function.  If s does not point to a null byte ('\0'), 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         top

       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.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).

       ┌──────────┬───────────────┬────────────────┐
       │Interface Attribute     Value          │
       ├──────────┼───────────────┼────────────────┤
       │mbtowc()  │ Thread safety │ MT-Unsafe race │
       └──────────┴───────────────┴────────────────┘

CONFORMING TO         top

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

NOTES         top

       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         top

       MB_CUR_MAX(3), mblen(3), mbrtowc(3), mbstowcs(3), wcstombs(3),
       wctomb(3)

COLOPHON         top

       This page is part of release 4.08 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                              2016-10-08                        MBTOWC(3)