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 ' ' 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 3.27 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)
