signbit.3: ffix

[thirdparty/man-pages.git] / man3 / fgetwc.3

.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
.\"
.\" %%%LICENSE_START(GPLv2+_DOC_ONEPARA)
.\" This is free documentation; you can redistribute it and/or
.\" modify it under the terms of the GNU General Public License as
.\" published by the Free Software Foundation; either version 2 of
.\" the License, or (at your option) any later version.
.\" %%%LICENSE_END
.\"
.\" References consulted:
.\"   GNU glibc-2 source code and manual
.\"   Dinkumware C library reference http://www.dinkumware.com/
.\"   OpenGroup's Single UNIX specification
.\"      http://www.UNIX-systems.org/online.html
.\"   ISO/IEC 9899:1999
.\"
.\" Modified Tue Oct 16 23:18:40 BST 2001 by John Levon <moz@compsoc.man.ac.uk>
.TH FGETWC 3  2015-08-08 "GNU" "Linux Programmer's Manual"
.SH NAME
fgetwc, getwc \- read a wide character from a FILE stream
.SH SYNOPSIS
.nf
.B #include <stdio.h>
.B #include <wchar.h>
.PP
.BI "wint_t fgetwc(FILE *" stream );
.BI "wint_t getwc(FILE *" stream );
.fi
.SH DESCRIPTION
The
.BR fgetwc ()
function is the wide-character equivalent
of the
.BR fgetc (3)
function.
It reads a wide character from \fIstream\fP and returns it.
If the end of stream is reached, or if \fIferror(stream)\fP becomes true,
it returns
.BR WEOF .
If a wide-character conversion error occurs, it sets
\fIerrno\fP to \fBEILSEQ\fP and returns
.BR WEOF .
.PP
The
.BR getwc ()
function or macro functions identically to
.BR fgetwc ().
It may be implemented as a macro, and may evaluate its argument
more than once.
There is no reason ever to use it.
.PP
For nonlocking counterparts, see
.BR unlocked_stdio (3).
.SH RETURN VALUE
The
.BR fgetwc ()
function returns the next wide-character
from the stream, or
.BR WEOF .
In the event of an error,
.I errno
is set to indicate the cause.
.SH ERRORS
Apart from the usual ones, there is
.TP
.B EILSEQ
The data obtained from the input stream does not
form a valid character.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbw17 lb lb
l l l.
Interface	Attribute	Value
T{
.BR fgetwc (),
.BR getwc ()
T}	Thread safety	MT-Safe
.TE
.SH CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99.
.SH NOTES
The behavior of
.BR fgetwc ()
depends on the
.B LC_CTYPE
category of the
current locale.
.PP
In the absence of additional information passed to the
.BR fopen (3)
call, it is
reasonable to expect that
.BR fgetwc ()
will actually read a multibyte sequence
from the stream and then convert it to a wide character.
.SH SEE ALSO
.BR fgetws (3),
.BR fputwc (3),
.BR ungetwc (3),
.BR unlocked_stdio (3)