1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 1997 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1988 AT&T */
28 /* All Rights Reserved */
29
30 /*
31 * University Copyright- Copyright (c) 1982, 1986, 1988
32 * The Regents of the University of California
33 * All Rights Reserved
34 *
35 * University Acknowledgment- Portions of this document are derived from
36 * software developed by the University of California, Berkeley, and its
37 * contributors.
38 */
39
40 #pragma ident "%Z%%M% %I% %E% SMI"
41
42 /*LINTLIBRARY*/
43
44 /*
45 * chkinput()
46 *
47 * Routine to check to see if any input is waiting.
48 * It returns a 1 if there is input waiting, and a zero if
49 * no input is waiting.
50 *
51 * This function replaces system calls to ioctl() with the FIONREAD
52 * parameter. It enables curses to stop a screen refresh whenever
53 * a character is input.
54 * Standard BTL UNIX 4.0 or 5.0 does not handle FIONREAD.
55 * Changes have been made to 'wrefresh.c' to
56 * call this routine as "_inputpending = chkinput()".
57 * (delay.c and getch.c also use FIONREAD for nodelay, select and fast peek,
58 * but these routines have not been changed).
59 *
60 * Philip N. Crusius - July 20, 1983
61 * Modified to handle various systems March 9, 1984 by Mark Horton.
62 */
63
64 #include <unistd.h>
65 #include <sys/types.h>
66 #include "curses_inc.h"
67
68 #ifdef FIONREAD
69 #define HAVE_CHK
70
71 int
_chkinput(void)72 _chkinput(void)
73 {
74 int i;
75
76 ioctl(SP->check_fd, FIONREAD, &i);
77 return (i > 0);
78 }
79 #endif /* FIONREAD */
80
81 #ifdef SELECT
82 #ifndef HAVE_CHK
83 #define HAVE_CHK
84
85 int
_chkinput(void)86 _chkinput(void)
87 {
88 int ifds, ofds, efds, n;
89 struct timeval tv;
90
91 ifds = 1 << SP->check_fd;
92 ofds = efds = 0;
93 tv.tv_sec = tv.t_usec = 0;
94 n = select(20, &ifds, &ofds, &efds, &tv);
95 return (n > 0);
96 }
97 #endif /* HAVE_CHK */
98 #endif /* SELECT */
99
100 #ifndef HAVE_CHK
101 #ifdef SYSV
102
103 int
_chkinput(void)104 _chkinput(void)
105 {
106 unsigned char c; /* character input */
107
108 /*
109 * Only check typeahead if the user is using our input
110 * routines. This is because the read below will put
111 * stuff into the inputQ that will never be read and the
112 * screen will never get updated from now on.
113 * This code should GO AWAY when a poll() or FIONREAD can
114 * be done on the file descriptor as then the check
115 * will be non-destructive.
116 */
117
118 if (!cur_term->fl_typeahdok ||
119 (cur_term->_chars_on_queue == INP_QSIZE) ||
120 (cur_term->_check_fd < 0)) {
121 goto bad;
122 }
123
124 /* If input is waiting in curses queue, return (TRUE). */
125
126 if ((int)cur_term->_chars_on_queue > 0) {
127 #ifdef DEBUG
128 if (outf) {
129 (void) fprintf(outf, "Found a character on the input "
130 "queue\n");
131 _print_queue();
132 }
133 #endif /* DEBUG */
134 goto good;
135 }
136
137 if (read(cur_term->_check_fd, (char *)&c, 1) > 0) {
138 #ifdef DEBUG
139 if (outf) {
140 (void) fprintf(outf, "Reading ahead\n");
141 }
142 #endif /* DEBUG */
143 /*
144 * A character was waiting. Put it at the end
145 * of the curses queue and return 1 to show that
146 * input is waiting.
147 */
148 #ifdef DEBUG
149 if (outf)
150 _print_queue();
151 #endif /* DEBUG */
152 cur_term->_input_queue[cur_term->_chars_on_queue++] = c;
153 good:
154 return (TRUE);
155 } else {
156 /* No input was waiting so return 0. */
157 #ifdef DEBUG
158 if (outf)
159 (void) fprintf(outf, "No input waiting\n");
160 #endif /* DEBUG */
161 bad:
162 return (FALSE);
163 }
164 }
165 #else /* SYSV */
166 int
_chkinput()167 _chkinput()
168 {
169 return (FALSE);
170 }
171 #endif /* SYSV */
172 #endif /* HAVE_CHK */
173
174 #ifdef DEBUG
175 void
_print_queue()176 _print_queue() /* FOR DEBUG ONLY */
177 {
178 int i, j = cur_term->_chars_on_queue;
179 chtype *inputQ = cur_term->_input_queue;
180
181 if (outf)
182 for (i = 0; i < j; i++)
183 (void) fprintf(outf, "inputQ[%d] = %c\n", i, inputQ[i]);
184 }
185 #endif /* DEBUG */
186