.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 
.TH "WCSTOMBS" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\" wcstombs 
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.SH NAME
wcstombs \- convert a wide-character string to a character string
.SH SYNOPSIS
.LP
\fB#include <stdlib.h>
.br
.sp
size_t wcstombs(char *restrict\fP \fIs\fP\fB, const wchar_t *restrict\fP
\fIpwcs\fP\fB,
.br
\ \ \ \ \ \  size_t\fP \fIn\fP\fB);
.br
\fP
.SH DESCRIPTION
.LP
The \fIwcstombs\fP() function shall convert the sequence of wide-character
codes that are in the array pointed to by
\fIpwcs\fP into a sequence of characters that begins in the initial
shift state and store these characters into the array pointed
to by \fIs\fP, stopping if a character would exceed the limit of \fIn\fP
total bytes or if a null byte is stored. Each
wide-character code shall be converted as if by a call to \fIwctomb\fP(),
except that the
shift state of \fIwctomb\fP() shall not be affected.
.LP
The behavior of this function shall be affected by the \fILC_CTYPE\fP
category of the current locale.
.LP
No more than \fIn\fP bytes shall be modified in the array pointed
to by \fIs\fP. If copying takes place between objects that
overlap, the behavior is undefined.  If \fIs\fP is a null pointer,
\fIwcstombs\fP() shall return the length required to convert
the entire array regardless of the value of \fIn\fP, but no values
are stored.
.LP
The \fIwcstombs\fP() function need not be reentrant. A function that
is not required to be reentrant is not required to be
thread-safe. 
.SH RETURN VALUE
.LP
If a wide-character code is encountered that does not correspond to
a valid character (of one or more bytes each),
\fIwcstombs\fP() shall return (\fBsize_t\fP)-1. Otherwise, \fIwcstombs\fP()
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
\fIn\fP.
.SH ERRORS
.LP
The \fIwcstombs\fP() function may fail if:
.TP 7
.B EILSEQ
A
wide-character code does not correspond to a valid character. 
.sp
.LP
\fIThe following sections are informative.\fP
.SH EXAMPLES
.LP
None.
.SH APPLICATION USAGE
.LP
None.
.SH RATIONALE
.LP
None.
.SH FUTURE DIRECTIONS
.LP
None.
.SH SEE ALSO
.LP
\fImblen\fP(), \fImbtowc\fP(), \fImbstowcs\fP(), \fIwctomb\fP(),
the Base Definitions volume of
IEEE\ Std\ 1003.1-2001, \fI<stdlib.h>\fP
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .