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 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 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 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 165 _chkinput() 166 { 167 return (FALSE); 168 } 169 #endif /* SYSV */ 170 #endif /* HAVE_CHK */ 171 172 #ifdef DEBUG 173 void 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