1.\" $NetBSD: wcstombs.3,v 1.13 2011/03/16 09:32:12 mbalmer Exp $ 2.\" 3.\" Copyright (c)2002 Citrus Project, 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.Dd March 16, 2011 28.Dt WCSTOMBS 3 29.Os 30.\" ---------------------------------------------------------------------- 31.Sh NAME 32.Nm wcstombs 33.Nd converts a wide-character string to a multibyte character string 34.\" ---------------------------------------------------------------------- 35.Sh LIBRARY 36.Lb libc 37.\" ---------------------------------------------------------------------- 38.Sh SYNOPSIS 39.In stdlib.h 40.Ft size_t 41.Fn wcstombs "char * restrict s" "const wchar_t * restrict pwcs" "size_t n" 42.\" ---------------------------------------------------------------------- 43.Sh DESCRIPTION 44.Fn wcstombs 45converts the nul-terminated wide-character string pointed to by 46.Fa pwcs 47to the corresponding multibyte character string, 48and stores it in the array pointed to by 49.Fa s . 50This function may modify the first at most 51.Fa n 52bytes of the array pointed to by 53.Fa s . 54Each character will be converted as if 55.Xr wctomb 3 56is continuously called, except the internal state of 57.Xr wctomb 3 58will not be affected. 59.Pp 60For state-dependent encoding, the 61.Fn wcstombs 62implies the result multibyte character string pointed to by 63.Fa s 64always to begin with an initial state. 65.Pp 66The behaviour of 67.Fn wcstombs 68is affected by the 69.Dv LC_CTYPE 70category of the current locale. 71.Pp 72These are the special cases: 73.Bl -tag -width 012345678901 74.It s == NULL 75The 76.Fn wcstombs 77returns the number of bytes to store the whole multibyte character string 78corresponding to the wide-character string pointed to by 79.Fa pwcs . 80In this case, 81.Fa n 82is ignored. 83.It pwcs == NULL 84Undefined (may cause the program to crash). 85.El 86.\" ---------------------------------------------------------------------- 87.Sh RETURN VALUES 88.Fn wcstombs 89returns: 90.Bl -tag -width 012345678901 91.It 0 or positive 92Number of bytes stored in the array pointed to by 93.Fa s . 94There are no cases that the value returned is greater than 95.Fa n 96(unless 97.Fa s 98is a null pointer). 99If the return value is equal to 100.Fa n , 101the string pointed to by 102.Fa s 103will not be nul-terminated. 104.It (size_t)-1 105.Fa pwcs 106points to a string containing an invalid wide character. 107.Fn wcstombs 108also sets 109.Va errno 110to indicate the error. 111.El 112.\" ---------------------------------------------------------------------- 113.Sh ERRORS 114.Fn wcstombs 115may cause an error in the following case: 116.Bl -tag -width Er 117.It Bq Er EILSEQ 118.Fa pwcs 119points to a string containing an invalid wide character. 120.El 121.\" ---------------------------------------------------------------------- 122.Sh SEE ALSO 123.Xr mbstowcs 3 , 124.Xr setlocale 3 , 125.Xr wctomb 3 126.\" ---------------------------------------------------------------------- 127.Sh STANDARDS 128The 129.Fn wcstombs 130function conforms to 131.St -ansiC . 132The restrict qualifier is added at 133.St -isoC-99 . 134