[unix-history] / lib / libc / stdio / 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.
.\"
.\" 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.
.\"
.\"     @(#)ferror.3	6.8 (Berkeley) 6/29/91
.\"
.Dd June 29, 1991
.Dt FERROR 3
.Os
.Sh NAME
.Nm clearerr ,
.Nm feof ,
.Nm ferror ,
.Nm fileno
.Nd check and reset stream status
.Sh SYNOPSIS
.Fd #include <stdio.h>
.Ft void
.Fn clearerr "FILE *stream"
.Ft int
.Fn feof "FILE *stream"
.Ft int
.Fn ferror "FILE *stream"
.Ft int
.Fn fileno "FILE *stream"
.Sh DESCRIPTION
The function
.Fn clearerr
clears the end-of-file and error indicators for the stream pointed
to by
.Fa stream .
.Pp
The function
.Fn feof
tests the end-of-file indicator for the stream pointed to by
.Fa stream ,
returning non-zero if it is set.
The end-of-file indicator can only be cleared by the function
.Fn clearerr .
.Pp
The function
.Fn ferror
tests the error indicator for the stream pointed to by
.Fa stream ,
returning non-zero if it is set.
The error indicator can only be reset by the
.Fn clearerr
function.
.Pp
The function
.Fn fileno
examines the argument
.Fa stream
and returns its integer descriptor.
.Sh ERRORS
These functions should not fail and do not set the external
variable
.Va errno .
.Sh SEE ALSO
.Xr open 2 ,
.Xr stdio 3
.Sh STANDARDS
The functions
.Fn clearerr ,
.Fn feof ,
and
.Fn ferror
conform to
.St -ansiC .
Commit	Line	Data
15637ed4 RG	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	.\"
	8	.\" Redistribution and use in source and binary forms, with or without
	9	.\" modification, are permitted provided that the following conditions
	10	.\" are met:
	11	.\" 1. Redistributions of source code must retain the above copyright
	12	.\" notice, this list of conditions and the following disclaimer.
	13	.\" 2. Redistributions in binary form must reproduce the above copyright
	14	.\" notice, this list of conditions and the following disclaimer in the
	15	.\" documentation and/or other materials provided with the distribution.
	16	.\" 3. All advertising materials mentioning features or use of this software
	17	.\" must display the following acknowledgement:
	18	.\" This product includes software developed by the University of
	19	.\" California, Berkeley and its contributors.
	20	.\" 4. Neither the name of the University nor the names of its contributors
	21	.\" may be used to endorse or promote products derived from this software
	22	.\" without specific prior written permission.
	23	.\"
	24	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	.\" SUCH DAMAGE.
	35	.\"
	36	.\" @(#)ferror.3 6.8 (Berkeley) 6/29/91
	37	.\"
	38	.Dd June 29, 1991
	39	.Dt FERROR 3
	40	.Os
	41	.Sh NAME
	42	.Nm clearerr ,
	43	.Nm feof ,
	44	.Nm ferror ,
	45	.Nm fileno
	46	.Nd check and reset stream status
	47	.Sh SYNOPSIS
	48	.Fd #include <stdio.h>
	49	.Ft void
	50	.Fn clearerr "FILE *stream"
	51	.Ft int
	52	.Fn feof "FILE *stream"
	53	.Ft int
	54	.Fn ferror "FILE *stream"
	55	.Ft int
	56	.Fn fileno "FILE *stream"
	57	.Sh DESCRIPTION
	58	The function
	59	.Fn clearerr
	60	clears the end-of-file and error indicators for the stream pointed
	61	to by
	62	.Fa stream .
	63	.Pp
	64	The function
65	.Fn feof
66	tests the end-of-file indicator for the stream pointed to by
67	.Fa stream ,
68	returning non-zero if it is set.
69	The end-of-file indicator can only be cleared by the function
70	.Fn clearerr .
71	.Pp
72	The function
73	.Fn ferror
74	tests the error indicator for the stream pointed to by
75	.Fa stream ,
76	returning non-zero if it is set.
77	The error indicator can only be reset by the
78	.Fn clearerr
79	function.
80	.Pp
81	The function
82	.Fn fileno
83	examines the argument
84	.Fa stream
c2714ef5	85	and returns its integer descriptor.
15637ed4 RG	86	.Sh ERRORS
	87	These functions should not fail and do not set the external
	88	variable
	89	.Va errno .
	90	.Sh SEE ALSO
	91	.Xr open 2 ,
	92	.Xr stdio 3
	93	.Sh STANDARDS
	94	The functions
	95	.Fn clearerr ,
	96	.Fn feof ,
	97	and
	98	.Fn ferror
	99	conform to
	100	.St -ansiC .