1 /* 2 * Mach Operating System 3 * Copyright (c) 1991,1990 Carnegie Mellon University 4 * All Rights Reserved. 5 * 6 * Permission to use, copy, modify and distribute this software and its 7 * documentation is hereby granted, provided that both the copyright 8 * notice and this permission notice appear in all copies of the 9 * software, derivative works or modified versions, and any portions 10 * thereof, and that both notices appear in supporting documentation. 11 * 12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 15 * 16 * Carnegie Mellon requests users of this software to return to 17 * 18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 19 * School of Computer Science 20 * Carnegie Mellon University 21 * Pittsburgh PA 15213-3890 22 * 23 * any improvements or extensions that they make and grant Carnegie the 24 * rights to redistribute these changes. 25 * 26 * Author: David B. Golub, Carnegie Mellon University 27 * Date: 7/90 28 * $Id: db_input.c,v 1.3 1993/12/18 04:46:33 mycroft Exp $ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/proc.h> 33 34 #include <ddb/db_output.h> 35 36 /* 37 * Character input and editing. 38 */ 39 40 /* 41 * We don't track output position while editing input, 42 * since input always ends with a new-line. We just 43 * reset the line position at the end. 44 */ 45 char * db_lbuf_start; /* start of input line buffer */ 46 char * db_lbuf_end; /* end of input line buffer */ 47 char * db_lc; /* current character */ 48 char * db_le; /* one past last character */ 49 50 #define CTRL(c) ((c) & 0x1f) 51 #define isspace(c) ((c) == ' ' || (c) == '\t') 52 #define BLANK ' ' 53 #define BACKUP '\b' 54 55 void 56 db_putstring(s, count) 57 char *s; 58 int count; 59 { 60 while (--count >= 0) 61 cnputc(*s++); 62 } 63 64 void 65 db_putnchars(c, count) 66 int c; 67 int count; 68 { 69 while (--count >= 0) 70 cnputc(c); 71 } 72 73 /* 74 * Delete N characters, forward or backward 75 */ 76 #define DEL_FWD 0 77 #define DEL_BWD 1 78 void 79 db_delete(n, bwd) 80 int n; 81 int bwd; 82 { 83 register char *p; 84 85 if (bwd) { 86 db_lc -= n; 87 db_putnchars(BACKUP, n); 88 } 89 for (p = db_lc; p < db_le-n; p++) { 90 *p = *(p+n); 91 cnputc(*p); 92 } 93 db_putnchars(BLANK, n); 94 db_putnchars(BACKUP, db_le - db_lc); 95 db_le -= n; 96 } 97 98 /* returns TRUE at end-of-line */ 99 int 100 db_inputchar(c) 101 int c; 102 { 103 switch (c) { 104 case CTRL('b'): 105 /* back up one character */ 106 if (db_lc > db_lbuf_start) { 107 cnputc(BACKUP); 108 db_lc--; 109 } 110 break; 111 case CTRL('f'): 112 /* forward one character */ 113 if (db_lc < db_le) { 114 cnputc(*db_lc); 115 db_lc++; 116 } 117 break; 118 case CTRL('a'): 119 /* beginning of line */ 120 while (db_lc > db_lbuf_start) { 121 cnputc(BACKUP); 122 db_lc--; 123 } 124 break; 125 case CTRL('e'): 126 /* end of line */ 127 while (db_lc < db_le) { 128 cnputc(*db_lc); 129 db_lc++; 130 } 131 break; 132 case CTRL('h'): 133 case 0177: 134 /* erase previous character */ 135 if (db_lc > db_lbuf_start) 136 db_delete(1, DEL_BWD); 137 break; 138 case CTRL('d'): 139 /* erase next character */ 140 if (db_lc < db_le) 141 db_delete(1, DEL_FWD); 142 break; 143 case CTRL('k'): 144 /* delete to end of line */ 145 if (db_lc < db_le) 146 db_delete(db_le - db_lc, DEL_FWD); 147 break; 148 case CTRL('t'): 149 /* twiddle last 2 characters */ 150 if (db_lc >= db_lbuf_start + 2) { 151 c = db_lc[-2]; 152 db_lc[-2] = db_lc[-1]; 153 db_lc[-1] = c; 154 cnputc(BACKUP); 155 cnputc(BACKUP); 156 cnputc(db_lc[-2]); 157 cnputc(db_lc[-1]); 158 } 159 break; 160 case CTRL('r'): 161 db_putstring("^R\n", 3); 162 if (db_le > db_lbuf_start) { 163 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 164 db_putnchars(BACKUP, db_le - db_lc); 165 } 166 break; 167 case '\n': 168 case '\r': 169 *db_le++ = c; 170 return (1); 171 default: 172 if (db_le == db_lbuf_end) { 173 cnputc('\007'); 174 } 175 else if (c >= ' ' && c <= '~') { 176 register char *p; 177 178 for (p = db_le; p > db_lc; p--) 179 *p = *(p-1); 180 *db_lc++ = c; 181 db_le++; 182 cnputc(c); 183 db_putstring(db_lc, db_le - db_lc); 184 db_putnchars(BACKUP, db_le - db_lc); 185 } 186 break; 187 } 188 return (0); 189 } 190 191 int 192 db_readline(lstart, lsize) 193 char * lstart; 194 int lsize; 195 { 196 db_force_whitespace(); /* synch output position */ 197 198 db_lbuf_start = lstart; 199 db_lbuf_end = lstart + lsize; 200 db_lc = lstart; 201 db_le = lstart; 202 203 while (!db_inputchar(cngetc())) 204 continue; 205 206 db_putchar('\n'); /* synch output position */ 207 208 *db_le = 0; 209 return (db_le - db_lbuf_start); 210 } 211 212 void 213 db_check_interrupt() 214 { 215 register int c; 216 217 c = cnmaygetc(); 218 switch (c) { 219 case -1: /* no character */ 220 return; 221 222 case CTRL('c'): 223 db_error((char *)0); 224 /*NOTREACHED*/ 225 226 case CTRL('s'): 227 do { 228 c = cnmaygetc(); 229 if (c == CTRL('c')) 230 db_error((char *)0); 231 } while (c != CTRL('q')); 232 break; 233 234 default: 235 /* drop on floor */ 236 break; 237 } 238 } 239 240 cnmaygetc () 241 { 242 return (-1); 243 } 244 245 /* called from kdb_trap in db_interface.c */ 246 cnpollc (flag) 247 { 248 } 249