xref: /original-bsd/lib/libc/stdio/ferror.3 (revision 990ad5b1)
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.
6.\" %sccs.include.redist.man%
7.\"
8.\"     @(#)ferror.3	6.7 (Berkeley) 04/19/91
9.\"
10.Dd
11.Dt FERROR 3
12.Os
13.Sh NAME
14.Nm clearerr ,
15.Nm feof ,
16.Nm ferror ,
17.Nm fileno
18.Nd check and reset stream status
19.Sh SYNOPSIS
20.Fd #include <stdio.h>
21.Ft void
22.Fn clearerr "FILE *stream"
23.Ft int
24.Fn feof "FILE *stream"
25.Ft int
26.Fn ferror "FILE *stream"
27.Ft int
28.Fn fileno "FILE *stream"
29.Sh DESCRIPTION
30The function
31.Fn clearerr
32clears the end-of-file and error indicators for the stream pointed
33to by
34.Fa stream .
35.Pp
36The function
37.Fn feof
38tests the end-of-file indicator for the stream pointed to by
39.Fa stream ,
40returning non-zero if it is set.
41The end-of-file indicator can only be cleared by the function
42.Fn clearerr .
43.Pp
44The function
45.Fn ferror
46tests the error indicator for the stream pointed to by
47.Fa stream ,
48returning non-zero if it is set.
49The error indicator can only be reset by the
50.Fn clearerr
51function.
52.Pp
53The function
54.Fn fileno
55examines the argument
56.Fa stream
57and returns its integer desciptor.
58.Sh ERRORS
59These functions should not fail and do not set the external
60variable
61.Va errno .
62.Sh SEE ALSO
63.Xr open 2 ,
64.Xr stdio 3
65.Sh STANDARDS
66The functions
67.Fn clearerr ,
68.Fn feof ,
69and
70.Fn ferror
71conform to
72.St -ansiC .
73