1.\" $OpenBSD: mbsrtowcs.3,v 1.4 2012/06/07 19:47:40 matthew Exp $ 2.\" $NetBSD: mbsrtowcs.3,v 1.6 2003/09/08 17:54:31 wiz Exp $ 3.\" 4.\" Copyright (c)2002 Citrus Project, 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd $Mdocdate: June 7 2012 $ 29.Dt MBSRTOWCS 3 30.Os 31.\" ---------------------------------------------------------------------- 32.Sh NAME 33.Nm mbsrtowcs , 34.Nm mbsnrtowcs 35.Nd converts a multibyte character string to a wide-character string \ 36(restartable) 37.\" ---------------------------------------------------------------------- 38.Sh SYNOPSIS 39.Fd #include <wchar.h> 40.Ft size_t 41.Fn mbsrtowcs "wchar_t * restrict dst" "const char ** restrict src" "size_t len" \ 42"mbstate_t * restrict ps" 43.Ft size_t 44.Fn mbsnrtowcs "wchar_t * restrict dst" "const char ** restrict src" "size_t nmc" \ 45"size_t len" "mbstate_t * restrict ps" 46.\" ---------------------------------------------------------------------- 47.Sh DESCRIPTION 48The 49.Fn mbsrtowcs 50function converts the multibyte character string indirectly pointed to by 51.Fa src 52to the corresponding wide-character string and stores it in the 53array pointed to by 54.Fa dst . 55The conversion stops due to the following reasons: 56.Bl -bullet 57.It 58The conversion reaches a null byte. 59In this case, the null byte is also converted. 60.It 61The conversion has already stored 62.Fa len 63wide characters. 64.It 65The conversion encounters an invalid character. 66.El 67.Pp 68The 69.Fn mbsnrtowcs 70function is equivalent to 71.Fn mbsrtowcs 72except that it will additionally stop the conversion after processing 73.Fa nmc 74bytes. 75.Pp 76Each character is converted as if 77.Xr mbrtowc 3 78is continuously called. 79.Pp 80After conversion, 81if 82.Fa dst 83is not a null pointer, 84the pointer object pointed to by 85.Fa src 86is a null pointer (if the conversion is stopped due to reaching a null byte) 87or the address just past the last byte processed. 88.Pp 89If 90.Fa dst 91is not a 92null pointer and the conversion is stopped due to reaching a null byte, 93the state object pointed to by 94.Fa ps 95is set to an initial state after the conversion has taken place. 96.Pp 97The behaviour of the 98.Fn mbsrtowcs 99and 100.Fn mbsnrtowcs 101functions is affected by the 102.Dv LC_CTYPE 103category of the current locale. 104.Pp 105There are two special cases: 106.Bl -tag -width 012345678901 107.It "dst == NULL" 108The conversion takes place, but the resultant wide-character string 109is discarded. 110In this case, the pointer object pointed to by 111.Fa src 112is not modified and 113.Fa len 114is ignored. 115.It "ps == NULL" 116The 117.Fn mbsrtowcs 118and 119.Fn mbsnrtowcs 120functions use their own internal state objects to keep the conversion state, 121instead of 122.Fa ps 123as mentioned in this manual page. 124.Pp 125Calling any other functions in 126.Em libc 127never change these internal states, 128which are initialized at startup time of the program. 129.El 130.\" ---------------------------------------------------------------------- 131.Sh RETURN VALUES 132The 133.Fn mbsrtowcs 134and 135.Fn mbsnrtowcs 136functions return: 137.Bl -tag -width 012345678901 138.It 0 or positive 139The value returned is the number of elements stored in the array pointed to by 140.Fa dst , 141except for a terminating null wide character (if any). 142If 143.Fa dst 144is not null and the value returned is equal to 145.Fa len , 146the wide-character string pointed to by 147.Fa dst 148is not null terminated. 149If 150.Fa dst 151is a null pointer, the value returned is the number of elements to contain 152the whole string converted, except for a terminating null wide character. 153.It (size_t)-1 154The array indirectly pointed to by 155.Fa src 156contains a byte sequence forming invalid character. 157In this case, 158.Va errno 159is set to indicate the error. 160.El 161.\" ---------------------------------------------------------------------- 162.Sh ERRORS 163The 164.Fn mbsrtowcs 165and 166.Fn mbsnrtowcs 167functions may return the following errors: 168.Bl -tag -width Er 169.It Bq Er EILSEQ 170The pointer pointed to by 171.Fa src 172points to an invalid or incomplete multibyte character. 173.It Bq Er EINVAL 174.Fa ps 175points to an invalid or uninitialized mbstate_t object. 176.El 177.\" ---------------------------------------------------------------------- 178.Sh SEE ALSO 179.Xr mbrtowc 3 , 180.Xr mbstowcs 3 , 181.Xr setlocale 3 182.\" ---------------------------------------------------------------------- 183.Sh STANDARDS 184The 185.Fn mbsrtowcs 186function conforms to 187.\" .St -isoC-amd1 . 188ISO/IEC 9899/AMD1:1995 189.Pq Dq ISO C90, Amendment 1 . 190The restrict qualifier is added at 191.\" .St -isoC99 . 192ISO/IEC 9899/1999 193.Dq Pq ISO C99 . 194.Pp 195The 196.Fn mbsnrtowcs 197function conforms to 198.St -p1003.1-2008 . 199