WCSTOMBS(3) Linux Programmer's Manual WCSTOMBS(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' '). In this case, the con-
version ends in the initial shift state. The number of bytes written to dest, excluding the terminating null 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 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 4.15 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/.
GNU
2017-09-15 WCSTOMBS(3)