bionic (3) mbsrtowcs.3posix.gz

PROLOG

       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

       mbsnrtowcs, mbsrtowcs — convert a character string to a wide-character string (restartable)

SYNOPSIS

       #include <wchar.h>

       size_t mbsnrtowcs(wchar_t *restrict dst, const char **restrict src,
           size_t nmc, size_t len, mbstate_t *restrict ps);
       size_t mbsrtowcs(wchar_t *restrict dst, const char **restrict src,
           size_t len, mbstate_t *restrict ps);

DESCRIPTION

       For  mbsrtowcs():  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.1‐2008 defers to the ISO C standard.

       The  mbsrtowcs()  function  shall  convert  a  sequence  of characters, beginning in the conversion state
       described by the object pointed to by ps, from the array indirectly pointed to by src into a sequence  of
       corresponding  wide  characters.  If  dst is not a null pointer, the converted characters shall be stored
       into the array pointed to by dst.  Conversion continues up to and including a terminating null character,
       which shall also be stored. Conversion shall stop early in either of the following cases:

        *  A sequence of bytes is encountered that does not form a valid character.

        *  len codes have been stored into the array pointed to by dst (and dst is not a null pointer).

       Each conversion shall take place as if by a call to the mbrtowc() function.

       If  dst  is  not  a  null  pointer,  the pointer object pointed to by src shall be assigned either a null
       pointer (if conversion stopped due to reaching a terminating null character) or the address just past the
       last  character  converted  (if any). If conversion stopped due to reaching a terminating null character,
       and if dst is not a null pointer, the resulting state described shall be the initial conversion state.

       If ps is a null pointer, the mbsrtowcs() function shall use its own internal mbstate_t object,  which  is
       initialized  at program start-up to the initial conversion state. Otherwise, the mbstate_t object pointed
       to by ps shall be used to completely describe the current conversion state of  the  associated  character
       sequence.

       The  mbsnrtowcs() function shall be equivalent to the mbsrtowcs() function, except that the conversion of
       characters pointed to by src is limited to at most nmc bytes (the size of the input buffer).

       The behavior of these functions shall be affected by the LC_CTYPE category of the current locale.

       The implementation shall behave as if no function defined in this  volume  of  POSIX.1‐2008  calls  these
       functions.

       The mbsnrtowcs() and mbsrtowcs() functions need not be thread-safe if called with a NULL ps argument.

       The mbsrtowcs() function shall not change the setting of errno if successful.

RETURN VALUE

       If  the  input  conversion encounters a sequence of bytes that do not form a valid character, an encoding
       error occurs. In this case, these functions shall store the value of the  macro  [EILSEQ]  in  errno  and
       shall  return (size_t)−1; the conversion state is undefined.  Otherwise, these functions shall return the
       number of characters successfully converted, not including the terminating null (if any).

ERRORS

       These functions shall fail if:

       EILSEQ An invalid character sequence is detected.

       These functions may fail if:

       EINVAL ps points to an object that contains an invalid conversion state.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       iconv(), mbrtowc(), mbsinit()

       The Base Definitions volume of POSIX.1‐2008, <wchar.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers,  Inc
       and  The  Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .