.\" Copyright (c) 1990, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
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.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
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.\"     @(#)strxfrm.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: head/lib/libc/string/strxfrm.3 251069 2013-05-28 20:57:40Z emaste $
.\"
.Dd June 4, 1993
.Dt STRXFRM 3
.Os
.Sh NAME
.Nm strxfrm
.Nd transform a string under locale
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In string.h
.Ft size_t
.Fn strxfrm "char * restrict dst" "const char * restrict src" "size_t n"
.Ft size_t
.Fn strxfrm_l "char * restrict dst" "const char *restrict src" "size_t n" "locale_t loc"
.Sh DESCRIPTION
The
.Fn strxfrm
function transforms a null-terminated string pointed to by
.Fa src
according to the current locale collation if any,
then copies the transformed string
into
.Fa dst .
Not more than
.Fa n
characters are copied into
.Fa dst ,
including the terminating null character added.
If
.Fa n
is set to 0
(it helps to determine an actual size needed
for transformation),
.Fa dst
is permitted to be a NULL pointer.
.Pp
Comparing two strings using
.Fn strcmp
after
.Fn strxfrm
is equal to comparing
two original strings with
.Fn strcoll .
.Pp
.Fn strxfrm_l
does the same, however takes an explicit
.Fa locale
rather than the global locale.
.Sh RETURN VALUES
Upon successful completion,
.Fn strxfrm
and
.Fn strxfrm_l
return the length of the transformed string not including
the terminating null character.
If this value is
.Fa n
or more, the contents of
.Fa dst
are indeterminate.
.Sh SEE ALSO
.Xr setlocale 3 ,
.Xr strcmp 3 ,
.Xr strcoll 3 ,
.Xr wcsxfrm 3
.Sh STANDARDS
The
.Fn strxfrm
function
conforms to
.St -isoC .
The
.Fn strxfrm_l
function conforms to
.St -p1003.1-2008 .