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 a NULL pointer, 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 conversion starts in the initial 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 L'\0'. In this case the conversion ends in the initial state. The number of bytes written to dest, excluding the terminating '\0' byte, 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 that no length limit exists.

In order to avoid the case 2 above, the programmer should make sure n is greater 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 multibyte sequence, not including the terminating null byte. If a wide character was encountered which could not be converted, (size_t) −1 is returned.

CONFORMING TO

C99.

NOTES

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

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

SEE ALSO

wcsrtombs(3)

COLOPHON

This page is part of release 3.24 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.


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

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.

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