WCRTOMB(3) Linux Programmer's Manual WCRTOMB(3)
NAME
wcrtomb - convert a wide character to a multibyte sequence
SYNOPSIS
#include <wchar.h>
size_t wcrtomb (char *s, wchar_t wc, mbstate_t *ps);
DESCRIPTION
The main case for this function is when s is not NULL and
wc is not L'\0'. In this case, the wcrtomb function con-
verts the wide character wc to its multibyte representa-
tion and stores it at the beginning of the character array
pointed to by s. It updates the shift state *ps, and
returns the length of said multibyte representation, i.e.
the number of bytes written at s.
A different case is when s is not NULL but wc is L'\0'. In
this case the wcrtomb function stores at the character
array pointed to by s the shift sequence needed to bring
*ps back to the initial state, followed by a '\0' byte. It
updates the shift state *ps (i.e. brings it into the ini-
tial state), and returns the length of the shift sequence
plus one, i.e. the number of bytes written at s.
A third case is when s is NULL. In this case wc is
ignored, and the function effectively returns wcr-
tomb(buf,L'\0',ps) where buf is an internal anonymous
buffer.
In all of the above cases, if ps is a NULL pointer, a
static anonymous state only known to the wcrtomb function
is used instead.
RETURN VALUE
The wcrtomb function returns the number of bytes that have
been or would have been written to the byte array at s. If
wc can not be represented as a multibyte sequence (accord-
ing to the current locale), (size_t)(-1) is returned, and
errno set to EILSEQ.
CONFORMING TO
ISO/ANSI C, UNIX98
SEE ALSO
wcsrtombs(3)
NOTES
The behaviour of wcrtomb depends on the LC_CTYPE category
of the current locale.
Passing NULL as ps is not multi-thread safe.
GNU July 25, 1999 1