wcsnrtombs

WCSNRTOMBS(3)              Linux Programmer's Manual             WCSNRTOMBS(3)



NAME
       wcsnrtombs - convert a wide character string to a multibyte string

SYNOPSIS
       #include <wchar.h>

       size_t wcsnrtombs(char *dest, const wchar_t **src, size_t nwc,
                          size_t len, mbstate_t *ps);

DESCRIPTION
       The wcsnrtombs function is like the wcsrtombs function, except that the
       number of wide characters to be converted, starting at *src, is limited
       to nwc.

       If dest is not a NULL pointer, the wcsnrtombs function converts at most
       nwc wide characters from the wide-character string *src to a  multibyte
       string  starting  at  dest.  At most len bytes are written to dest. The
       shift state *ps is updated. The conversion is effectively performed  by
       repeatedly  calling  wcrtomb(dest,*src,ps),  as  long as this call suc-
       ceeds, and then incrementing dest by the number of  bytes  written  and
       *src by one. The conversion can stop for three reasons:

       1. A wide character has been encountered that can not be represented as
       a multibyte sequence (according to the current locale).  In  this  case
       *src  is  left  pointing to the invalid wide character, (size_t)(-1) is
       returned, and errno is set to EILSEQ.

       2. nwc wide characters  have  been  converted  without  encountering  a
       L'\0',  or  the  length  limit forces a stop. In this case *src is left
       pointing to the next wide character to be converted, and the number  of
       bytes written to dest is returned.

       3.  The  wide-character string has been completely converted, including
       the terminating L'\0' (which has the side effect of bringing  back  *ps
       to the initial state). In this case *src is set to NULL, and the number
       of bytes written to dest,  excluding  the  terminating  '\0'  byte,  is
       returned.

       If  dest is NULL, len is ignored, and the conversion proceeds as above,
       except that the converted bytes are not written out to memory, and that
       no destination length limit exists.

       In both of the above cases, if ps is a NULL pointer, a static anonymous
       state only known to the wcsnrtombs function is used instead.

       The programmer must ensure that there is room for at least len bytes at
       dest.

RETURN VALUE
       The  wcsnrtombs  function  returns the number of bytes that make up the
       converted part of multibyte sequence,  not  including  the  terminating
       null byte.  If a wide character was encountered which could not be con-
       verted, (size_t)(-1) is returned, and errno set to EILSEQ.

CONFORMING TO
       This function is a GNU extension.

SEE ALSO
       wcsrtombs(3), iconv(3)

NOTES
       The behaviour of wcsnrtombs depends on the  LC_CTYPE  category  of  the
       current locale.

       Passing NULL as ps is not multi-thread safe.



GNU                               1999-07-25                     WCSNRTOMBS(3)