xref: /netbsd-src/distrib/utils/more/ttyin.c (revision 27578b9aac214cc7796ead81dcc5427e79d5f2a0)
1 /*	$NetBSD: ttyin.c,v 1.3 1998/02/04 11:09:13 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1988 Mark Nudleman
5  * Copyright (c) 1988, 1993
6  *	The Regents of the University of California.  All rights reserved.
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 
37 #include <sys/cdefs.h>
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)ttyin.c	8.1 (Berkeley) 6/6/93";
41 #else
42 __RCSID("$NetBSD: ttyin.c,v 1.3 1998/02/04 11:09:13 christos Exp $");
43 #endif
44 #endif /* not lint */
45 
46 /*
47  * Routines dealing with getting input from the keyboard (i.e. from the user).
48  */
49 
50 #include <sys/types.h>
51 
52 #include "less.h"
53 #include "extern.h"
54 
55 static int tty;
56 
57 /*
58  * Open keyboard for input.
59  * (Just use file descriptor 2.)
60  */
61 void
62 open_getchr()
63 {
64 	tty = 2;
65 }
66 
67 /*
68  * Get a character from the keyboard.
69  */
70 int
71 getchr()
72 {
73 	char c;
74 	int result;
75 
76 	do
77 	{
78 		result = iread(tty, &c, 1);
79 		if (result == READ_INTR)
80 			return (READ_INTR);
81 		if (result < 0)
82 		{
83 			/*
84 			 * Don't call error() here,
85 			 * because error calls getchr!
86 			 */
87 			quit();
88 		}
89 	} while (result != 1);
90 	return (c & 0177);
91 }
92