1MBRLEN(3P)                 POSIX Programmer's Manual                MBRLEN(3P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
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NAME

12       mbrlen - get number of bytes in a character (restartable)
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SYNOPSIS

15       #include <wchar.h>
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17       size_t mbrlen(const char *restrict s, size_t n,
18              mbstate_t *restrict ps);
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DESCRIPTION

22       If s is not a null pointer, mbrlen()  shall  determine  the  number  of
23       bytes  constituting  the character pointed to by s. It shall be equiva‐
24       lent to:
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27              mbstate_t internal;
28              mbrtowc(NULL, s, n, ps != NULL ? ps : &internal);
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30       If ps is a null pointer, the mbrlen() function shall use its own inter‐
31       nal  mbstate_t  object, which is initialized at program start-up to the
32       initial conversion state. Otherwise, the mbstate_t object pointed to by
33       ps shall be used to completely describe the current conversion state of
34       the associated character sequence. The implementation shall  behave  as
35       if  no  function  defined  in this volume of IEEE Std 1003.1-2001 calls
36       mbrlen().
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38       The behavior of this function is affected by the LC_CTYPE  category  of
39       the current locale.
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RETURN VALUE

42       The  mbrlen()  function  shall  return  the first of the following that
43       applies:
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45       0      If the next n or fewer bytes complete the character that  corre‐
46              sponds to the null wide character.
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48       positive
49              If  the  next  n  or fewer bytes complete a valid character; the
50              value returned shall be the number of bytes  that  complete  the
51              character.
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53       (size_t)-2
54              If  the next n bytes contribute to an incomplete but potentially
55              valid character, and all n bytes have been processed. When n has
56              at least the value of the {MB_CUR_MAX} macro, this case can only
57              occur if s points at a sequence  of  redundant  shift  sequences
58              (for implementations with state-dependent encodings).
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60       (size_t)-1
61              If  an  encoding error occurs, in which case the next n or fewer
62              bytes do not contribute to a complete and  valid  character.  In
63              this  case, [EILSEQ] shall be stored in errno and the conversion
64              state is undefined.
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ERRORS

68       The mbrlen() function may fail if:
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70       EINVAL ps points to an  object  that  contains  an  invalid  conversion
71              state.
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73       EILSEQ Invalid character sequence is detected.
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76       The following sections are informative.
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EXAMPLES

79       None.
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APPLICATION USAGE

82       None.
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RATIONALE

85       None.
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FUTURE DIRECTIONS

88       None.
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SEE ALSO

91       mbsinit(),     mbrtowc(),    the    Base    Definitions    volume    of
92       IEEE Std 1003.1-2001, <wchar.h>
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95       Portions of this text are reprinted and reproduced in  electronic  form
96       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
97       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
98       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
99       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
100       event of any discrepancy between this version and the original IEEE and
101       The Open Group Standard, the original IEEE and The Open Group  Standard
102       is  the  referee document. The original Standard can be obtained online
103       at http://www.opengroup.org/unix/online.html .
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107IEEE/The Open Group                  2003                           MBRLEN(3P)
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