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