mbtowc(3p) [centos man page]

MBTOWC(3P)						     POSIX Programmer's Manual							MBTOWC(3P)

PROLOG

       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME

       mbtowc - convert a character to a wide-character code

SYNOPSIS

       #include <stdlib.h>

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

DESCRIPTION

       If s is not a null pointer, mbtowc() shall determine the number of bytes that constitute the character pointed  to  by  s.  It  shall  then
       determine  the  wide-character code for the value of type wchar_t that corresponds to that character. (The value of the wide-character code
       corresponding to the null byte is 0.) If the character is valid and pwc is not a null pointer, mbtowc() shall store the wide-character code
       in the object pointed to by pwc.

       The  behavior of this function is affected by the LC_CTYPE category of the current locale. For a state-dependent encoding, this function is
       placed into its initial state by a call for which its character pointer argument, s, is a null pointer.	Subsequent calls with s  as  other
       than  a null pointer shall cause the internal state of the function to be altered as necessary. A call with s as a null pointer shall cause
       this function to return a non-zero value if encodings have state dependency, and 0 otherwise. If the implementation employs  special  bytes
       to  change  the	shift state, these bytes shall not produce separate wide-character codes, but shall be grouped with an adjacent character.
       Changing the LC_CTYPE category causes the shift state of this function to be unspecified. At most n bytes of the  array	pointed  to  by  s
       shall be examined.

       The implementation shall behave as if no function defined in this volume of IEEE Std 1003.1-2001 calls mbtowc().

RETURN VALUE

       If  s  is a null pointer, mbtowc() shall return a non-zero or 0 value, if character encodings, respectively, do or do not have state-depen-
       dent encodings. If s is not a null pointer, mbtowc() shall either return 0 (if s points to the null byte), or return the  number  of  bytes
       that  constitute the converted character (if the next n or fewer bytes form a valid character), or return -1  and may set errno to indicate
       the error  (if they do not form a valid character).

       In no case shall the value returned be greater than n or the value of the {MB_CUR_MAX} macro.

ERRORS

       The mbtowc() function may fail if:

       EILSEQ Invalid character sequence is detected.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       mblen(), mbstowcs(), wctomb(), wcstombs(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and  the  original  IEEE
       and  The  Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained
       online at http://www.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003								MBTOWC(3P)