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mblen(3p) — Linux manual page

MBLEN(3P)               POSIX Programmer's ManualMBLEN(3P)

PROLOG        top

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

NAME        top

       mblen — get number of bytes in a character

SYNOPSIS        top

       #include <stdlib.h>       int mblen(const char *s, size_tn);

DESCRIPTION        top

       The functionality described on this reference page is aligned with       the ISO C standard. Any conflict between the requirements       described here and the ISO C standard is unintentional. This       volume of POSIX.1‐2017 defers to the ISO C standard.       Ifs is not a null pointer,mblen() shall determine the number of       bytes constituting the character pointed to bys.  Except that the       shift state ofmbtowc() 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 POSIX.1‐2017 callsmblen().       The behavior of this function is affected by theLC_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 withs as other than a null pointer shall cause       the internal state of the function to be altered as necessary. A       call withs 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 theLC_CTYPE category causes the shift state of this       function to be unspecified.       Themblen() function need not be thread-safe.

RETURN VALUE        top

       Ifs 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. Ifs is not a null pointer,mblen()       shall either return 0 (ifs points to the null byte), or return       the number of bytes that constitute the character (if the nextn       or fewer bytes form a valid character), or return -1 (if they do       not form a valid character) and may seterrno to indicate the       error.  In no case shall the value returned be greater thann or       the value of the {MB_CUR_MAX} macro.

ERRORS        top

       Themblen() function may fail if:EILSEQAn invalid character sequence is detected. In the POSIX              locale an[EILSEQ]error cannot occur since all byte values              are valid characters.The following sections are informative.

EXAMPLES        top

       None.

APPLICATION USAGE        top

       None.

RATIONALE        top

       None.

FUTURE DIRECTIONS        top

       None.

SEE ALSO        top

mbtowc(3p),mbstowcs(3p),wctomb(3p),wcstombs(3p)       The Base Definitions volume of POSIX.1‐2017,stdlib.h(0p)

COPYRIGHT        top

       Portions of this text are reprinted and reproduced in electronic       form from IEEE Std 1003.1-2017, Standard for Information       Technology -- Portable Operating System Interface (POSIX), The       Open Group Base Specifications Issue 7, 2018 Edition, Copyright       (C) 2018 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 athttp://www.opengroup.org/unix/online.html .       Any typographical or formatting errors that appear in this page       are most likely to have been introduced during the conversion of       the source files to man page format. To report such errors, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017MBLEN(3P)

Pages that refer to this page:ctype.h(0p), stdlib.h(0p), mbstowcs(3p), mbtowc(3p), setlocale(3p), wcstombs(3p), wctomb(3p)

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