1 /* $OpenBSD: ttyin.c,v 1.2 2001/01/29 01:58:04 niklas Exp $ */ 2 3 /* 4 * Copyright (c) 1984,1985,1989,1994,1995 Mark Nudelman 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice in the documentation and/or other materials provided with 14 * the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY 17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 22 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 23 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 25 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN 26 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 30 /* 31 * Routines dealing with getting input from the keyboard (i.e. from the user). 32 */ 33 34 #include "less.h" 35 36 static int tty; 37 38 /* 39 * Open keyboard for input. 40 */ 41 public void 42 open_getchr() 43 { 44 #if MSOFTC || OS2 45 extern int fd0; 46 /* 47 * Open a new handle to CON: in binary mode 48 * for unbuffered keyboard read. 49 */ 50 fd0 = dup(0); 51 close(0); 52 tty = OPEN_TTYIN(); 53 #else 54 /* 55 * Try /dev/tty. 56 * If that doesn't work, use file descriptor 2, 57 * which in Unix is usually attached to the screen, 58 * but also usually lets you read from the keyboard. 59 */ 60 tty = OPEN_TTYIN(); 61 if (tty < 0) 62 tty = 2; 63 #endif 64 } 65 66 /* 67 * Get a character from the keyboard. 68 */ 69 public int 70 getchr() 71 { 72 char c; 73 int result; 74 75 do 76 { 77 #if MSOFTC 78 /* 79 * In raw read, we don't see ^C so look here for it. 80 */ 81 flush(); 82 c = getch(); 83 result = 1; 84 if (c == '\003') 85 return (READ_INTR); 86 #else 87 #if OS2 88 flush(); 89 while (_read_kbd(0, 0, 0) != -1) 90 continue; 91 if ((c = _read_kbd(0, 1, 0)) == -1) 92 return (READ_INTR); 93 result = 1; 94 #else 95 result = iread(tty, &c, sizeof(char)); 96 if (result == READ_INTR) 97 return (READ_INTR); 98 if (result < 0) 99 { 100 /* 101 * Don't call error() here, 102 * because error calls getchr! 103 */ 104 quit(QUIT_ERROR); 105 } 106 #endif 107 #endif 108 /* 109 * Various parts of the program cannot handle 110 * an input character of '\0'. 111 * If a '\0' was actually typed, convert it to '\340' here. 112 */ 113 if (c == '\0') 114 c = '\340'; 115 } while (result != 1); 116 117 return (c & 0377); 118 } 119