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 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 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 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 167 _chkinput() 168 { 169 return (FALSE); 170 } 171 #endif /* SYSV */ 172 #endif /* HAVE_CHK */ 173 174 #ifdef DEBUG 175 void 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