.\" $NetBSD: wcsrtombs.3,v 1.13.56.1 2024/10/11 17:34:00 martin Exp $ .\" .\" Copyright (c)2002 Citrus Project, .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .Dd August 27, 2017 .Dt WCSRTOMBS 3 .Os .\" ---------------------------------------------------------------------- .Sh NAME .Nm wcsrtombs , .Nm wcsnrtombs .Nd converts a wide-character string to a multibyte character string \ (restartable) .\" ---------------------------------------------------------------------- .Sh LIBRARY .Lb libc .\" ---------------------------------------------------------------------- .Sh SYNOPSIS . .In wchar.h . .Ft size_t .Fo wcsrtombs .Fa "char * restrict s" .Fa "const wchar_t ** restrict pwcs" .Fa "size_t n" "mbstate_t * restrict ps" .Fc . .Ft size_t .Fo wcsnrtombs .Fa "char * restrict s" .Fa "const wchar_t ** restrict pwcs" .Fa "size_t nwc" .Fa "size_t n" .Fa "mbstat_t * restrict ps" .Fc . .\" ---------------------------------------------------------------------- .Sh DESCRIPTION The .Fn wcsrtombs function converts the NUL-terminated wide-character string indirectly pointed to by .Fa pwcs to the corresponding multibyte character string, and stores it in the array pointed to by .Fa s . The conversion stops due to the following reasons: .Bl -bullet .It The conversion reaches a NUL wide character. In this case, the NUL wide character is also converted. .It The .Fn wcsrtombs has already stored .Fa n bytes in the array pointed to by .Fa s . .It The conversion encounters an invalid character. .El .Pp Each character will be converted as if .Xr wcrtomb 3 is continuously called, except the internal state of .Xr wcrtomb 3 will not be affected. .Pp After conversion, if .Fa s is not a NULL pointer, the pointer object pointed to by .Fa pwcs is a NULL pointer .Pq if the conversion is stopped due to reaching a NUL wide character or points to the first byte of the character just after the last character converted. .Pp If .Fa s is not a NULL pointer and the conversion is stopped due to reaching a NUL wide character, .Fn wcsrtombs places the state object pointed to by .Fa ps to an initial state after the conversion is taken place. .Pp The behavior of .Fn wcsrtombs is affected by the .Dv LC_CTYPE category of the current locale. .Pp These are the special cases: .Bl -tag -width Li .It Li "s == NULL" .Fn wcsrtombs returns the number of bytes to store the whole multibyte character string corresponding to the wide-character string pointed to by .Fa pwcs , not including the terminating NUL byte. In this case, .Fa n is ignored. .It Li "pwcs == NULL || *pwcs == NULL" Undefined (may cause the program to crash). .It Li "ps == NULL" .Fn wcsrtombs uses its own internal state object to keep the conversion state, instead of .Fa ps mentioned in this manual page. .Pp Calling any other functions in .Lb libc never changes the internal state of .Fn wcsrtombs , which is initialized at startup time of the program. .El .Pp The .Fn wcsnrtombs function behaves identically to .Fn wcsrtombs , except that the conversion stops after reading at most .Fa nwc characters from the buffer pointed to by .Fa pwcs . .\" ---------------------------------------------------------------------- .Sh RETURN VALUES The .Fn wcsrtombs and .Fn wcsnrtombs functions return: .Bl -tag -width Li .It Li 0 , No or positive Number of bytes stored in the array pointed to by .Fa s , except for a NUL byte. There are no cases that the value returned is greater than .Fa n .Po unless .Fa s is a NULL pointer .Pc . If the return value is equal to .Fa n , the string pointed to by .Fa s will not be NUL-terminated. .It Li "(size_t)-1" .Fa pwcs points to a string containing an invalid wide character. The .Fn wcsrtombs also sets .Va errno to indicate the error. .El .\" ---------------------------------------------------------------------- .Sh ERRORS The .Fn wcsrtombs and .Fn wcsnrtombs functions may fail with the following errors: .Bl -tag -width Er .It Bq Er EILSEQ .Fa pwcs points to a string containing an invalid wide character. .It Bq Er EINVAL .Fa ps points to an invalid or uninitialized .Vt mbstate_t object. .El .\" ---------------------------------------------------------------------- .Sh SEE ALSO .Xr setlocale 3 , .Xr wcrtomb 3 , .Xr wcstombs 3 .\" ---------------------------------------------------------------------- .Sh STANDARDS The .Fn wcsrtombs function conforms to .St -ansiC . The .Li restrict qualifier was added by .St -isoC-99 . .Pp The .Fn wcsnrtombs function conforms to .St -p1003.1-2008 .