'\" et
.TH TOWCTRANS "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.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
towctrans,
towctrans_l
\(em wide-character transliteration
.SH SYNOPSIS
.LP
.nf
#include <wctype.h>
.P
wint_t towctrans(wint_t \fIwc\fP, wctrans_t \fIdesc\fP);
wint_t towctrans_l(wint_t \fIwc\fP, wctrans_t \fIdesc\fP,
    locale_t \fIlocale\fP);
.fi
.SH DESCRIPTION
For
\fItowctrans\fR():
The functionality described on this reference page is aligned with the
ISO\ C standard. Any conflict between the requirements described here and the
ISO\ C standard is unintentional. This volume of POSIX.1\(hy2017 defers to the ISO\ C standard.
.P
The
\fItowctrans\fR()
and
\fItowctrans_l\fR()
functions shall transliterate the wide-character code
.IR wc
using the mapping described by
.IR desc .
.P
The current setting of the
.IR LC_CTYPE
category in the current locale
or in the locale represented by
.IR locale ,
respectively, should be the same as during the call to
\fIwctrans\fR()
or
\fIwctrans_l\fR()
that returned the value
.IR desc .
.P
If the value of
.IR desc
is invalid (that is, not obtained by a call to
\fIwctrans\fR()
or
.IR desc
is invalidated by a subsequent call to
\fIsetlocale\fR()
that has affected category
.IR LC_CTYPE ),
the result is unspecified.
.P
If the value of
.IR desc
is invalid (that is, not obtained by a call to
\fIwctrans_l\fR()
with the same locale object
.IR locale )
the result is unspecified.
.P
An application wishing to check for error situations should set
.IR errno
to 0 before calling
\fItowctrans\fR()
or
\fItowctrans_l\fR().
.P
If
.IR errno
is non-zero on return, an error has occurred.
.P
The behavior is undefined if the
.IR locale
argument to
\fItowctrans_l\fR()
is the special locale object LC_GLOBAL_LOCALE or is not a valid locale
object handle.
.SH "RETURN VALUE"
If successful, the
\fItowctrans\fR()
and
\fItowctrans_l\fR()
functions shall return the mapped value of
.IR wc
using the mapping described by
.IR desc .
Otherwise, they shall return
.IR wc
unchanged.
.SH ERRORS
These functions may fail if:
.TP
.BR EINVAL
.IR desc
contains an invalid transliteration descriptor.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
The strings
.BR \(dqtolower\(dq 
and
.BR \(dqtoupper\(dq 
are reserved for the standard mapping names. In the table below, the
functions in the left column are equivalent to the functions in the
right column.
.sp
.RS 4
.nf

towlower(\fIwc\fP)            towctrans(\fIwc\fP, wctrans("tolower"))
towlower_l(\fIwc\fP, \fIlocale\fP)  towctrans_l(\fIwc\fP, wctrans("tolower"), \fIlocale\fP)
towupper(\fIwc\fP)            towctrans(\fIwc\fP, wctrans("toupper"))
towupper_l(\fIwc\fP, \fIlocale\fP)  towctrans_l(\fIwc\fP, wctrans("toupper"), \fIlocale\fP)
.fi
.P
.RE
.SH RATIONALE
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fItowlower\fR\^(\|)",
.IR "\fItowupper\fR\^(\|)",
.IR "\fIwctrans\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<wctype.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 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 .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .