centos man page for mblen

MBLEN(3P)						     POSIX Programmer's Manual							 MBLEN(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
       mblen - get number of bytes in a character

SYNOPSIS
       #include <stdlib.h>

       int mblen(const char *s, size_t n);

DESCRIPTION
       If s is not a null pointer, mblen() shall determine the number of bytes constituting the character pointed to by s. Except that	the  shift
       state of mbtowc() is not affected, it shall be equivalent to:

	      mbtowc((wchar_t *)0, s, n);

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

       The  behavior  of  this	function is affected by the LC_CTYPE category of the current locale. For a state-dependent encoding, this function
       shall be 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 charac-
       ter. Changing the LC_CTYPE category causes the shift state of this function to be unspecified.

RETURN VALUE
       If s is a null pointer, mblen() shall return a non-zero or 0 value, if character encodings, respectively, do or do not have state-dependent
       encodings.  If  s  is  not a null pointer, mblen() shall either return 0 (if s points to the null byte), or return the number of bytes that
       constitute the character (if the next n or fewer bytes form a valid character), or return -1 (if they do not form a valid  character)   and
       may set errno to indicate the error.  In no case shall the value returned be greater than n or the value of the {MB_CUR_MAX} macro.

ERRORS
       The mblen() 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
       mbtowc(), 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								 MBLEN(3P)