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

.\" Copyright (c) 1990, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
.\"
.\" %%%LICENSE_START(BSD_4_CLAUSE_UCB)
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\" %%%LICENSE_END
.\"
.\"     @(#)ferror.3	6.8 (Berkeley) 6/29/91
.\"
.\"
.\" Converted for Linux, Mon Nov 29 14:24:40 1993, faith@cs.unc.edu
.\" Added remark on EBADF for fileno, aeb, 2001-03-22
.\"
.TH FERROR 3  2016-03-15 "" "Linux Programmer's Manual"
.SH NAME
clearerr, feof, ferror, fileno \- check and reset stream status
.SH SYNOPSIS
.B #include <stdio.h>
.sp
.BI "void clearerr(FILE *" stream );

.BI "int feof(FILE *" stream );

.BI "int ferror(FILE *" stream );

.BI "int fileno(FILE *" stream );
.sp
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.in
.sp
.BR fileno ():
_POSIX_C_SOURCE
.SH DESCRIPTION
The function
.BR clearerr ()
clears the end-of-file and error indicators for the stream pointed to by
.IR stream .
.PP
The function
.BR feof ()
tests the end-of-file indicator for the stream pointed to by
.IR stream ,
returning nonzero if it is set.
The end-of-file indicator can be cleared only by the function
.BR clearerr ().
.PP
The function
.BR ferror ()
tests the error indicator for the stream pointed to by
.IR stream ,
returning nonzero if it is set.
The error indicator can be reset only by the
.BR clearerr ()
function.
.PP
The function
.BR fileno ()
examines the argument
.I stream
and returns its integer file descriptor.
.PP
For nonlocking counterparts, see
.BR unlocked_stdio (3).
.SH ERRORS
These functions should not fail and do not set the external variable
.IR errno .
(However, in case
.BR fileno ()
detects that its argument is not a valid stream, it must
return \-1 and set
.I errno
to
.BR EBADF .)
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbw19 lb lb
l l l.
Interface	Attribute	Value
T{
.BR clearerr (),
.BR feof (),
.br
.BR ferror (),
.BR fileno ()
T}	Thread safety	MT-Safe
.TE
.SH CONFORMING TO
The functions
.BR clearerr (),
.BR feof (),
and
.BR ferror ()
conform to C89, C99, POSIX.1-2001, and POSIX.1-2008.

The function
.BR fileno ()
conforms to POSIX.1-2001 and POSIX.1-2008.
.SH SEE ALSO
.BR open (2),
.BR fdopen (3),
.BR stdio (3),
.BR unlocked_stdio (3)
Commit	Line	Data
fea681da MK	1	.\" Copyright (c) 1990, 1991 The Regents of the University of California.
	2	.\" 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	.\"
a9cd9cb7	8	.\" %%%LICENSE_START(BSD_4_CLAUSE_UCB)
fea681da MK	9	.\" Redistribution and use in source and binary forms, with or without
	10	.\" modification, are permitted provided that the following conditions
	11	.\" are met:
	12	.\" 1. Redistributions of source code must retain the above copyright
	13	.\" notice, this list of conditions and the following disclaimer.
	14	.\" 2. Redistributions in binary form must reproduce the above copyright
	15	.\" notice, this list of conditions and the following disclaimer in the
	16	.\" documentation and/or other materials provided with the distribution.
	17	.\" 3. All advertising materials mentioning features or use of this software
	18	.\" must display the following acknowledgement:
	19	.\" This product includes software developed by the University of
	20	.\" California, Berkeley and its contributors.
	21	.\" 4. Neither the name of the University nor the names of its contributors
	22	.\" may be used to endorse or promote products derived from this software
	23	.\" without specific prior written permission.
	24	.\"
	25	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	26	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	27	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	28	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	29	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	30	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	31	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	32	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	33	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	34	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	35	.\" SUCH DAMAGE.
8c9302dc	36	.\" %%%LICENSE_END
fea681da MK	37	.\"
	38	.\" @(#)ferror.3 6.8 (Berkeley) 6/29/91
	39	.\"
	40	.\"
	41	.\" Converted for Linux, Mon Nov 29 14:24:40 1993, faith@cs.unc.edu
	42	.\" Added remark on EBADF for fileno, aeb, 2001-03-22
	43	.\"
97986708	44	.TH FERROR 3 2016-03-15 "" "Linux Programmer's Manual"
fea681da MK	45	.SH NAME
	46	clearerr, feof, ferror, fileno \- check and reset stream status
	47	.SH SYNOPSIS
	48	.B #include <stdio.h>
	49	.sp
	50	.BI "void clearerr(FILE *" stream );
5895e7eb	51
fea681da	52	.BI "int feof(FILE *" stream );
9f8eecdb	53
fea681da	54	.BI "int ferror(FILE *" stream );
5895e7eb	55
fea681da	56	.BI "int fileno(FILE *" stream );
cc4615cc MK	57	.sp
	58	.in -4n
	59	Feature Test Macro Requirements for glibc (see
	60	.BR feature_test_macros (7)):
	61	.in
	62	.sp
	63	.BR fileno ():
cff459de	64	_POSIX_C_SOURCE
fea681da MK	65	.SH DESCRIPTION
fea681da MK	66	The function
e511ffb6	67	.BR clearerr ()
fea681da MK	68	clears the end-of-file and error indicators for the stream pointed to by
	69	.IR stream .
	70	.PP
	71	The function
e511ffb6	72	.BR feof ()
fea681da MK	73	tests the end-of-file indicator for the stream pointed to by
fea681da MK	74	.IR stream ,
c7094399	75	returning nonzero if it is set.
33a0ccb2	76	The end-of-file indicator can be cleared only by the function
e511ffb6	77	.BR clearerr ().
fea681da MK	78	.PP
fea681da MK	79	The function
e511ffb6	80	.BR ferror ()
fea681da MK	81	tests the error indicator for the stream pointed to by
fea681da MK	82	.IR stream ,
c7094399	83	returning nonzero if it is set.
33a0ccb2	84	The error indicator can be reset only by the
e511ffb6	85	.BR clearerr ()
fea681da MK	86	function.
	87	.PP
	88	The function
e511ffb6	89	.BR fileno ()
fea681da MK	90	examines the argument
fea681da MK	91	.I stream
d9cb0d7d	92	and returns its integer file descriptor.
fea681da	93	.PP
24b74457	94	For nonlocking counterparts, see
fea681da MK	95	.BR unlocked_stdio (3).
	96	.SH ERRORS
	97	These functions should not fail and do not set the external variable
	98	.IR errno .
	99	(However, in case
e511ffb6	100	.BR fileno ()
fea681da MK	101	detects that its argument is not a valid stream, it must
	102	return \-1 and set
	103	.I errno
	104	to
	105	.BR EBADF .)
82e25934	106	.SH ATTRIBUTES
0952a69a MK	107	For an explanation of the terms used in this section, see
	108	.BR attributes (7).
	109	.TS
	110	allbox;
	111	lbw19 lb lb
	112	l l l.
	113	Interface Attribute Value
	114	T{
82e25934 PH	115	.BR clearerr (),
82e25934 PH	116	.BR feof (),
0952a69a	117	.br
8ee22ae8	118	.BR ferror (),
82e25934	119	.BR fileno ()
0952a69a MK	120	T} Thread safety MT-Safe
0952a69a MK	121	.TE
47297adb	122	.SH CONFORMING TO
fea681da	123	The functions
e511ffb6 MK	124	.BR clearerr (),
e511ffb6 MK	125	.BR feof (),
fea681da	126	and
e511ffb6	127	.BR ferror ()
28d286ed	128	conform to C89, C99, POSIX.1-2001, and POSIX.1-2008.
f76e404e MK	129
	130	The function
	131	.BR fileno ()
	132	conforms to POSIX.1-2001 and POSIX.1-2008.
47297adb	133	.SH SEE ALSO
fea681da	134	.BR open (2),
78ba016d	135	.BR fdopen (3),
fea681da MK	136	.BR stdio (3),
fea681da MK	137	.BR unlocked_stdio (3)