Section (3) wcstombs


Linux manual pages Section 3  

Name

wcstombs — convert a wide-character string to a multibyte string

Synopsis

#include <stdlib.h>
size_t wcstombs( char *dest,
  const wchar_t *src,
  size_t n);
 

DESCRIPTION

If dest is not NULL, the wcstombs() function converts the wide-character string src to a multibyte string starting at dest. At most n bytes are written to dest. The sequence of characters placed in dest begins in the initial shift state. 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, (size_t) −1 is returned.

  2. The length limit forces a stop. In this case, the number of bytes written to dest is returned, but the shift state at this point is lost.

  3. The wide-character string has been completely converted, including the terminating null wide character (L_zsingle_quotesz__zsingle_quotesz_). In this case, the conversion ends in the initial shift state. The number of bytes written to dest, excluding the terminating null byte (_zsingle_quotesz__zsingle_quotesz_), is returned.

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

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

In order to avoid the case 2 above, the programmer should make sure n is greater than or equal to wcstombs(NULL,src,0)+1.

RETURN VALUE

The wcstombs() function returns the number of bytes that make up the converted part of a multibyte sequence, not including the terminating null byte. If a wide character was encountered which could not be converted, (size_t) −1 is returned.

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
wcstombs() Thread safety MT-Safe

CONFORMING TO

POSIX.1-2001, POSIX.1-2008, C99.

NOTES

The behavior of wcstombs() depends on the LC_CTYPE category of the current locale.

The function wcsrtombs(3) provides a better interface to the same functionality.

SEE ALSO

mblen(3), mbstowcs(3), mbtowc(3), wcsrtombs(3) wctomb(3)

COLOPHON

This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man−pages/.


  Copyright (c) Bruno Haible <haibleclisp.cons.org>

%%%LICENSE_START(GPLv2+_DOC_ONEPARA)
This is free documentation; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
%%%LICENSE_END

References consulted:
  GNU glibc-2 source code and manual
  Dinkumware C library reference http://www.dinkumware.com/
  OpenGroup_zsingle_quotesz_s Single UNIX specification http://www.UNIX-systems.org/online.html
  ISO/IEC 9899:1999