1 /*
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are permitted
6 * provided that the above copyright notice and this paragraph are
7 * duplicated in all such forms and that any documentation,
8 * and/or other materials related to such
9 * distribution and use acknowledge that the software was developed
10 * by the University of California, Berkeley. The name of the
11 * University may not be used to endorse or promote products derived
12 * from this software without specific prior written permission.
13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16 */
17
18 /*
19 FUNCTION
20 <<clearerr>>, <<clearerr_unlocked>>---clear file or stream error indicator
21
22 INDEX
23 clearerr
24 INDEX
25 clearerr_unlocked
26
27 SYNOPSIS
28 #include <stdio.h>
29 void clearerr(FILE *<[fp]>);
30
31 #define _BSD_SOURCE
32 #include <stdio.h>
33 void clearerr_unlocked(FILE *<[fp]>);
34
35 DESCRIPTION
36 The <<stdio>> functions maintain an error indicator with each file
37 pointer <[fp]>, to record whether any read or write errors have
38 occurred on the associated file or stream. Similarly, it maintains an
39 end-of-file indicator to record whether there is no more data in the
40 file.
41
42 Use <<clearerr>> to reset both of these indicators.
43
44 See <<ferror>> and <<feof>> to query the two indicators.
45
46 <<clearerr_unlocked>> is a non-thread-safe version of <<clearerr>>.
47 <<clearerr_unlocked>> may only safely be used within a scope
48 protected by flockfile() (or ftrylockfile()) and funlockfile(). This
49 function may safely be used in a multi-threaded program if and only
50 if they are called while the invoking thread owns the (FILE *)
51 object, as is the case after a successful call to the flockfile() or
52 ftrylockfile() functions. If threads are disabled, then
53 <<clearerr_unlocked>> is equivalent to <<clearerr>>.
54
55 RETURNS
56 <<clearerr>> does not return a result.
57
58 PORTABILITY
59 ANSI C requires <<clearerr>>.
60
61 <<clearerr_unlocked>> is a BSD extension also provided by GNU libc.
62
63 No supporting OS subroutines are required.
64 */
65
66 #define _DEFAULT_SOURCE
67 #include <_ansi.h>
68 #include <stdio.h>
69 #include "local.h"
70
71 /* A subroutine version of the macro clearerr. */
72
73 #undef clearerr
74
75 void
clearerr(FILE * fp)76 clearerr (FILE * fp)
77 {
78 CHECK_INIT(_REENT, fp);
79 _newlib_flockfile_start (fp);
80 __sclearerr (fp);
81 _newlib_flockfile_end (fp);
82 }
83
