1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Chris Torek and the American National Standards Committee X3, 6.\" on Information Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" @(#)strxfrm.3 8.1 (Berkeley) 6/4/93 37.\" FreeBSD: src/lib/libc/string/strxfrm.3,v 1.16 2002/09/06 11:24:06 tjr Exp 38.\" $FreeBSD$ 39.\" 40.Dd October 4, 2002 41.Dt WCSXFRM 3 42.Os 43.Sh NAME 44.Nm wcsxfrm 45.Nd transform a wide string under locale 46.Sh LIBRARY 47.Lb libc 48.Sh SYNOPSIS 49.In wchar.h 50.Ft size_t 51.Fn wcsxfrm "wchar_t * restrict dst" "const wchar_t * restrict src" "size_t n" 52.Sh DESCRIPTION 53The 54.Fn wcsxfrm 55function transforms a null-terminated wide character string pointed to by 56.Fa src 57according to the current locale collation order 58then copies the transformed string 59into 60.Fa dst . 61No more than 62.Fa n 63wide characters are copied into 64.Fa dst , 65including the terminating null character added. 66If 67.Fa n 68is set to 0 69(it helps to determine an actual size needed 70for transformation), 71.Fa dst 72is permitted to be a 73.Dv NULL 74pointer. 75.Pp 76Comparing two strings using 77.Fn wcscmp 78after 79.Fn wcsxfrm 80is equivalent to comparing 81two original strings with 82.Fn wcscoll . 83.Sh RETURN VALUES 84Upon successful completion, 85.Fn wcsxfrm 86returns the length of the transformed string not including 87the terminating null character. 88If this value is 89.Fa n 90or more, the contents of 91.Fa dst 92are indeterminate. 93.Sh SEE ALSO 94.Xr setlocale 3 , 95.Xr strxfrm 3 , 96.Xr wcscmp 3 , 97.Xr wcscoll 3 98.Sh STANDARDS 99The 100.Fn wcsxfrm 101function 102conforms to 103.St -isoC-99 . 104.Sh BUGS 105The current implementation of 106.Fn wcsxfrm 107only works in single-byte 108.Dv LC_CTYPE 109locales, and falls back to using 110.Fn wcsncpy 111in locales with extended character sets. 112.Pp 113Comparing two strings using 114.Fn wcscmp 115after 116.Fn wcsxfrm 117is 118.Em not 119always equivalent to comparison with 120.Fn wcscoll ; 121.Fn wcsxfrm 122only stores information about primary collation weights into 123.Fa dst , 124whereas 125.Fn wcscoll 126compares characters using both primary and secondary weights. 127