WCSTOMBS(3) Library Functions Manual WCSTOMBS(3)

NAME

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

SYNOPSIS

#include <stdlib.h>

size_t wcstombs(char *restrict s, const wchar_t *restrict pwcs,
       size_t n);

DESCRIPTION

[CX] 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 wcstombs () function shall convert the sequence of wide-character codes that are in the array pointed to by pwcs into a sequence of characters that begins in the initial shift state and store these characters into the array pointed to by s, stopping if a character would exceed the limit of n total bytes or if a null byte is stored. Each wide-character code shall be converted as if by a call to wctomb(3), except that the shift state of wctomb(3) shall not be affected.

The behavior of this function shall be affected by the LC_CTYPE category of the current locale.

No more than n bytes shall be modified in the array pointed to by s. If copying takes place between objects that overlap, the behavior is undefined. [CX] If s is a null pointer, wcstombs () shall return the length required to convert the entire array regardless of the value of n, but no values are stored.

RETURN VALUE

If a wide-character code is encountered that does not correspond to a valid character (of one or more bytes each), wcstombs () shall return ( size_t) -1. Otherwise, wcstombs () shall return the number of bytes stored in the character array, not including any terminating null byte. The array shall not be null-terminated if the value returned is n.