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 /*LINTLIBRARY*/
41
42 /*
43 * chkinput()
44 *
45 * Routine to check to see if any input is waiting.
46 * It returns a 1 if there is input waiting, and a zero if
47 * no input is waiting.
48 *
49 * This function replaces system calls to ioctl() with the FIONREAD
50 * parameter. It enables curses to stop a screen refresh whenever
51 * a character is input.
52 * Standard BTL UNIX 4.0 or 5.0 does not handle FIONREAD.
53 * Changes have been made to 'wrefresh.c' to
54 * call this routine as "_inputpending = chkinput()".
55 * (delay.c and getch.c also use FIONREAD for nodelay, select and fast peek,
56 * but these routines have not been changed).
57 *
58 * Philip N. Crusius - July 20, 1983
59 * Modified to handle various systems March 9, 1984 by Mark Horton.
60 */
61
62 #include <unistd.h>
63 #include <sys/types.h>
64 #include "curses_inc.h"
65
66 #ifdef FIONREAD
67 #define HAVE_CHK
68
69 int
_chkinput(void)70 _chkinput(void)
71 {
72 int i;
73
74 ioctl(SP->check_fd, FIONREAD, &i);
75 return (i > 0);
76 }
77 #endif /* FIONREAD */
78
79 #ifdef SELECT
80 #ifndef HAVE_CHK
81 #define HAVE_CHK
82
83 int
_chkinput(void)84 _chkinput(void)
85 {
86 int ifds, ofds, efds, n;
87 struct timeval tv;
88
89 ifds = 1 << SP->check_fd;
90 ofds = efds = 0;
91 tv.tv_sec = tv.t_usec = 0;
92 n = select(20, &ifds, &ofds, &efds, &tv);
93 return (n > 0);
94 }
95 #endif /* HAVE_CHK */
96 #endif /* SELECT */
97
98 #ifndef HAVE_CHK
99 #ifdef SYSV
100
101 int
_chkinput(void)102 _chkinput(void)
103 {
104 unsigned char c; /* character input */
105
106 /*
107 * Only check typeahead if the user is using our input
108 * routines. This is because the read below will put
109 * stuff into the inputQ that will never be read and the
110 * screen will never get updated from now on.
111 * This code should GO AWAY when a poll() or FIONREAD can
112 * be done on the file descriptor as then the check
113 * will be non-destructive.
114 */
115
116 if (!cur_term->fl_typeahdok ||
117 (cur_term->_chars_on_queue == INP_QSIZE) ||
118 (cur_term->_check_fd < 0)) {
119 goto bad;
120 }
121
122 /* If input is waiting in curses queue, return (TRUE). */
123
124 if ((int)cur_term->_chars_on_queue > 0) {
125 #ifdef DEBUG
126 if (outf) {
127 (void) fprintf(outf, "Found a character on the input "
128 "queue\n");
129 _print_queue();
130 }
131 #endif /* DEBUG */
132 goto good;
133 }
134
135 if (read(cur_term->_check_fd, (char *)&c, 1) > 0) {
136 #ifdef DEBUG
137 if (outf) {
138 (void) fprintf(outf, "Reading ahead\n");
139 }
140 #endif /* DEBUG */
141 /*
142 * A character was waiting. Put it at the end
143 * of the curses queue and return 1 to show that
144 * input is waiting.
145 */
146 #ifdef DEBUG
147 if (outf)
148 _print_queue();
149 #endif /* DEBUG */
150 cur_term->_input_queue[cur_term->_chars_on_queue++] = c;
151 good:
152 return (TRUE);
153 } else {
154 /* No input was waiting so return 0. */
155 #ifdef DEBUG
156 if (outf)
157 (void) fprintf(outf, "No input waiting\n");
158 #endif /* DEBUG */
159 bad:
160 return (FALSE);
161 }
162 }
163 #else /* SYSV */
164 int
_chkinput()165 _chkinput()
166 {
167 return (FALSE);
168 }
169 #endif /* SYSV */
170 #endif /* HAVE_CHK */
171
172 #ifdef DEBUG
173 void
_print_queue()174 _print_queue() /* FOR DEBUG ONLY */
175 {
176 int i, j = cur_term->_chars_on_queue;
177 chtype *inputQ = cur_term->_input_queue;
178
179 if (outf)
180 for (i = 0; i < j; i++)
181 (void) fprintf(outf, "inputQ[%d] = %c\n", i, inputQ[i]);
182 }
183 #endif /* DEBUG */
184