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 <<getchar>>---read a character (macro)
21 
22 INDEX
23 	getchar
24 INDEX
25 	_getchar_r
26 
27 SYNOPSIS
28 	#include <stdio.h>
29 	int getchar(void);
30 
31 	int _getchar_r(struct _reent *<[reent]>);
32 
33 DESCRIPTION
34 <<getchar>> is a macro, defined in <<stdio.h>>.  You can use <<getchar>>
35 to get the next single character from the standard input stream.
36 As a side effect, <<getchar>> advances the standard input's
37 current position indicator.
38 
39 The alternate function <<_getchar_r>> is a reentrant version.  The
40 extra argument <[reent]> is a pointer to a reentrancy structure.
41 
42 
43 RETURNS
44 The next character (read as an <<unsigned char>>, and cast to
45 <<int>>), unless there is no more data, or the host system reports a
46 read error; in either of these situations, <<getchar>> returns <<EOF>>.
47 
48 You can distinguish the two situations that cause an <<EOF>> result by
49 using `<<ferror(stdin)>>' and `<<feof(stdin)>>'.
50 
51 PORTABILITY
52 ANSI C requires <<getchar>>; it suggests, but does not require, that
53 <<getchar>> be implemented as a macro.
54 
55 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
56 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
57 */
58 
59 #if defined(LIBC_SCCS) && !defined(lint)
60 static char sccsid[] = "%W% (Berkeley) %G%";
61 #endif /* LIBC_SCCS and not lint */
62 
63 /*
64  * A subroutine version of the macro getchar.
65  */
66 
67 #define _DEFAULT_SOURCE
68 #include <_ansi.h>
69 #include <stdio.h>
70 #include "local.h"
71 
72 #undef getchar
73 
74 int
getchar(void)75 getchar (void)
76 {
77   /* CHECK_INIT is called (eventually) by __srefill_r.  */
78   _REENT_SMALL_CHECK_INIT (_REENT);
79   return getc ( stdin );
80 }
81