db_input.c revision 1.2
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 (at) 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 /* 27 * $Id: db_input.c,v 1.2 1993/05/20 03:39:15 cgd Exp $ 28 * 29 * HISTORY 30 * $Log: db_input.c,v $ 31 * Revision 1.2 1993/05/20 03:39:15 cgd 32 * add explicit rcs id 33 * 34 * Revision 1.1.1.1 1993/03/21 09:46:26 cgd 35 * initial import of 386bsd-0.1 sources 36 * 37 * Revision 1.1 1992/03/25 21:45:10 pace 38 * Initial revision 39 * 40 * Revision 2.4 91/02/14 14:41:53 mrt 41 * Add input line editing. 42 * [90/11/11 dbg] 43 * 44 * Revision 2.3 91/02/05 17:06:32 mrt 45 * Changed to new Mach copyright 46 * [91/01/31 16:18:13 mrt] 47 * 48 * Revision 2.2 90/08/27 21:51:03 dbg 49 * Reduce lint. 50 * [90/08/07 dbg] 51 * Created. 52 * [90/07/25 dbg] 53 * 54 */ 55 /* 56 * Author: David B. Golub, Carnegie Mellon University 57 * Date: 7/90 58 */ 59 60 #include "param.h" 61 #include "proc.h" 62 #include <ddb/db_output.h> 63 64 /* 65 * Character input and editing. 66 */ 67 68 /* 69 * We don't track output position while editing input, 70 * since input always ends with a new-line. We just 71 * reset the line position at the end. 72 */ 73 char * db_lbuf_start; /* start of input line buffer */ 74 char * db_lbuf_end; /* end of input line buffer */ 75 char * db_lc; /* current character */ 76 char * db_le; /* one past last character */ 77 78 #define CTRL(c) ((c) & 0x1f) 79 #define isspace(c) ((c) == ' ' || (c) == '\t') 80 #define BLANK ' ' 81 #define BACKUP '\b' 82 83 void 84 db_putstring(s, count) 85 char *s; 86 int count; 87 { 88 while (--count >= 0) 89 cnputc(*s++); 90 } 91 92 void 93 db_putnchars(c, count) 94 int c; 95 int count; 96 { 97 while (--count >= 0) 98 cnputc(c); 99 } 100 101 /* 102 * Delete N characters, forward or backward 103 */ 104 #define DEL_FWD 0 105 #define DEL_BWD 1 106 void 107 db_delete(n, bwd) 108 int n; 109 int bwd; 110 { 111 register char *p; 112 113 if (bwd) { 114 db_lc -= n; 115 db_putnchars(BACKUP, n); 116 } 117 for (p = db_lc; p < db_le-n; p++) { 118 *p = *(p+n); 119 cnputc(*p); 120 } 121 db_putnchars(BLANK, n); 122 db_putnchars(BACKUP, db_le - db_lc); 123 db_le -= n; 124 } 125 126 /* returns TRUE at end-of-line */ 127 int 128 db_inputchar(c) 129 int c; 130 { 131 switch (c) { 132 case CTRL('b'): 133 /* back up one character */ 134 if (db_lc > db_lbuf_start) { 135 cnputc(BACKUP); 136 db_lc--; 137 } 138 break; 139 case CTRL('f'): 140 /* forward one character */ 141 if (db_lc < db_le) { 142 cnputc(*db_lc); 143 db_lc++; 144 } 145 break; 146 case CTRL('a'): 147 /* beginning of line */ 148 while (db_lc > db_lbuf_start) { 149 cnputc(BACKUP); 150 db_lc--; 151 } 152 break; 153 case CTRL('e'): 154 /* end of line */ 155 while (db_lc < db_le) { 156 cnputc(*db_lc); 157 db_lc++; 158 } 159 break; 160 case CTRL('h'): 161 case 0177: 162 /* erase previous character */ 163 if (db_lc > db_lbuf_start) 164 db_delete(1, DEL_BWD); 165 break; 166 case CTRL('d'): 167 /* erase next character */ 168 if (db_lc < db_le) 169 db_delete(1, DEL_FWD); 170 break; 171 case CTRL('k'): 172 /* delete to end of line */ 173 if (db_lc < db_le) 174 db_delete(db_le - db_lc, DEL_FWD); 175 break; 176 case CTRL('t'): 177 /* twiddle last 2 characters */ 178 if (db_lc >= db_lbuf_start + 2) { 179 c = db_lc[-2]; 180 db_lc[-2] = db_lc[-1]; 181 db_lc[-1] = c; 182 cnputc(BACKUP); 183 cnputc(BACKUP); 184 cnputc(db_lc[-2]); 185 cnputc(db_lc[-1]); 186 } 187 break; 188 case CTRL('r'): 189 db_putstring("^R\n", 3); 190 if (db_le > db_lbuf_start) { 191 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 192 db_putnchars(BACKUP, db_le - db_lc); 193 } 194 break; 195 case '\n': 196 case '\r': 197 *db_le++ = c; 198 return (1); 199 default: 200 if (db_le == db_lbuf_end) { 201 cnputc('\007'); 202 } 203 else if (c >= ' ' && c <= '~') { 204 register char *p; 205 206 for (p = db_le; p > db_lc; p--) 207 *p = *(p-1); 208 *db_lc++ = c; 209 db_le++; 210 cnputc(c); 211 db_putstring(db_lc, db_le - db_lc); 212 db_putnchars(BACKUP, db_le - db_lc); 213 } 214 break; 215 } 216 return (0); 217 } 218 219 int 220 db_readline(lstart, lsize) 221 char * lstart; 222 int lsize; 223 { 224 db_force_whitespace(); /* synch output position */ 225 226 db_lbuf_start = lstart; 227 db_lbuf_end = lstart + lsize; 228 db_lc = lstart; 229 db_le = lstart; 230 231 while (!db_inputchar(cngetc())) 232 continue; 233 234 db_putchar('\n'); /* synch output position */ 235 236 *db_le = 0; 237 return (db_le - db_lbuf_start); 238 } 239 240 void 241 db_check_interrupt() 242 { 243 register int c; 244 245 c = cnmaygetc(); 246 switch (c) { 247 case -1: /* no character */ 248 return; 249 250 case CTRL('c'): 251 db_error((char *)0); 252 /*NOTREACHED*/ 253 254 case CTRL('s'): 255 do { 256 c = cnmaygetc(); 257 if (c == CTRL('c')) 258 db_error((char *)0); 259 } while (c != CTRL('q')); 260 break; 261 262 default: 263 /* drop on floor */ 264 break; 265 } 266 } 267 268 cnmaygetc () 269 { 270 return (-1); 271 } 272 273 /* called from kdb_trap in db_interface.c */ 274 cnpollc (flag) 275 { 276 } 277
Indexes created Thu Oct 02 14:10:14 GMT 2025