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 <<fgetc>>, <<fgetc_unlocked>>---get a character from a file or stream
21
22 INDEX
23 fgetc
24 INDEX
25 fgetc_unlocked
26 INDEX
27 _fgetc_r
28 INDEX
29 _fgetc_unlocked_r
30
31 SYNOPSIS
32 #include <stdio.h>
33 int fgetc(FILE *<[fp]>);
34
35 #define _BSD_SOURCE
36 #include <stdio.h>
37 int fgetc_unlocked(FILE *<[fp]>);
38
39 #include <stdio.h>
40 int fgetc( FILE *<[fp]>);
41
42 #define _BSD_SOURCE
43 #include <stdio.h>
44 int fgetc_unlocked( FILE *<[fp]>);
45
46 DESCRIPTION
47 Use <<fgetc>> to get the next single character from the file or stream
48 identified by <[fp]>. As a side effect, <<fgetc>> advances the file's
49 current position indicator.
50
51 For a macro version of this function, see <<getc>>.
52
53 <<fgetc_unlocked>> is a non-thread-safe version of <<fgetc>>.
54 <<fgetc_unlocked>> may only safely be used within a scope
55 protected by flockfile() (or ftrylockfile()) and funlockfile(). This
56 function may safely be used in a multi-threaded program if and only
57 if they are called while the invoking thread owns the (FILE *)
58 object, as is the case after a successful call to the flockfile() or
59 ftrylockfile() functions. If threads are disabled, then
60 <<fgetc_unlocked>> is equivalent to <<fgetc>>.
61
62 The functions <<_fgetc_r>> and <<_fgetc_unlocked_r>> are simply reentrant
63 versions that are passed the additional reentrant structure pointer
64 argument: <[ptr]>.
65
66 RETURNS
67 The next character (read as an <<unsigned char>>, and cast to
68 <<int>>), unless there is no more data, or the host system reports a
69 read error; in either of these situations, <<fgetc>> returns <<EOF>>.
70
71 You can distinguish the two situations that cause an <<EOF>> result by
72 using the <<ferror>> and <<feof>> functions.
73
74 PORTABILITY
75 ANSI C requires <<fgetc>>.
76
77 <<fgetc_unlocked>> is a BSD extension also provided by GNU libc.
78
79 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
80 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
81 */
82
83 #define _DEFAULT_SOURCE
84 #include <_ansi.h>
85 #include <stdio.h>
86 #include "local.h"
87
88 int
fgetc(FILE * fp)89 fgetc (
90 FILE * fp)
91 {
92 int result;
93 CHECK_INIT(ptr, fp);
94 _newlib_flockfile_start (fp);
95 result = _sgetc ( fp);
96 _newlib_flockfile_end (fp);
97 return result;
98 }
99
100
