.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 
.TH "STRXFRM" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\" strxfrm 
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.SH NAME
strxfrm \- string transformation
.SH SYNOPSIS
.LP
\fB#include <string.h>
.br
.sp
size_t strxfrm(char *restrict\fP \fIs1\fP\fB, const char *restrict\fP
\fIs2\fP\fB, size_t\fP \fIn\fP\fB);
.br
\fP
.SH DESCRIPTION
.LP
The \fIstrxfrm\fP() function shall transform the string pointed to
by \fIs2\fP and place the resulting string into the array
pointed to by \fIs1\fP. The transformation is such that if \fIstrcmp\fP()
is applied to
two transformed strings, it shall return a value greater than, equal
to, or less than 0, corresponding to the result of \fIstrcoll\fP()
applied to the same two original strings. No more than \fIn\fP bytes
are placed
into the resulting array pointed to by \fIs1\fP, including the terminating
null byte. If \fIn\fP is 0, \fIs1\fP is permitted to
be a null pointer. If copying takes place between objects that overlap,
the behavior is undefined.
.LP
The
\fIstrxfrm\fP() function shall not change the setting of \fIerrno\fP
if successful.
.LP
Since no return value is reserved to indicate an error, an application
wishing to check for error situations should set
\fIerrno\fP to 0, then call \fIstrxfrm\fP(), then check \fIerrno\fP.
.SH RETURN VALUE
.LP
Upon successful completion, \fIstrxfrm\fP() shall return the length
of the transformed string (not including the terminating
null byte). If the value returned is \fIn\fP or more, the contents
of the array pointed to by \fIs1\fP are unspecified.
.LP
On
error, \fIstrxfrm\fP() may set \fIerrno\fP but no return value is
reserved to indicate an error. 
.SH ERRORS
.LP
The \fIstrxfrm\fP() function may fail if:
.TP 7
.B EINVAL
The string pointed to by the \fIs2\fP argument contains characters
outside the domain of the collating sequence. 
.sp
.LP
\fIThe following sections are informative.\fP
.SH EXAMPLES
.LP
None.
.SH APPLICATION USAGE
.LP
The transformation function is such that two transformed strings can
be ordered by \fIstrcmp\fP() as appropriate to collating sequence
information in the program's locale (category
\fILC_COLLATE ).\fP
.LP
The fact that when \fIn\fP is 0 \fIs1\fP is permitted to be a null
pointer is useful to determine the size of the \fIs1\fP
array prior to making the transformation.
.SH RATIONALE
.LP
None.
.SH FUTURE DIRECTIONS
.LP
None.
.SH SEE ALSO
.LP
\fIstrcmp\fP(), \fIstrcoll\fP(), the Base Definitions volume of
IEEE\ Std\ 1003.1-2001, \fI<string.h>\fP
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .