db_input.c revision 1.2.4.1
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 1.2.4.1 1993/11/14 22:48:34 mycroft Exp $ 28 * 29 * HISTORY 30 * $Log: db_input.c,v $ 31 * Revision 1.2.4.1 1993/11/14 22:48:34 mycroft 32 * Canonicalize all #includes. 33 * 34 * Revision 1.2 1993/05/20 03:39:15 cgd 35 * add explicit rcs id 36 * 37 * Revision 1.1.1.1 1993/03/21 09:46:26 cgd 38 * initial import of 386bsd-0.1 sources 39 * 40 * Revision 1.1 1992/03/25 21:45:10 pace 41 * Initial revision 42 * 43 * Revision 2.4 91/02/14 14:41:53 mrt 44 * Add input line editing. 45 * [90/11/11 dbg] 46 * 47 * Revision 2.3 91/02/05 17:06:32 mrt 48 * Changed to new Mach copyright 49 * [91/01/31 16:18:13 mrt] 50 * 51 * Revision 2.2 90/08/27 21:51:03 dbg 52 * Reduce lint. 53 * [90/08/07 dbg] 54 * Created. 55 * [90/07/25 dbg] 56 * 57 */ 58 /* 59 * Author: David B. Golub, Carnegie Mellon University 60 * Date: 7/90 61 */ 62 63 #include <sys/param.h> 64 #include <sys/proc.h> 65 66 #include <ddb/db_output.h> 67 68 /* 69 * Character input and editing. 70 */ 71 72 /* 73 * We don't track output position while editing input, 74 * since input always ends with a new-line. We just 75 * reset the line position at the end. 76 */ 77 char * db_lbuf_start; /* start of input line buffer */ 78 char * db_lbuf_end; /* end of input line buffer */ 79 char * db_lc; /* current character */ 80 char * db_le; /* one past last character */ 81 82 #define CTRL(c) ((c) & 0x1f) 83 #define isspace(c) ((c) == ' ' || (c) == '\t') 84 #define BLANK ' ' 85 #define BACKUP '\b' 86 87 void 88 db_putstring(s, count) 89 char *s; 90 int count; 91 { 92 while (--count >= 0) 93 cnputc(*s++); 94 } 95 96 void 97 db_putnchars(c, count) 98 int c; 99 int count; 100 { 101 while (--count >= 0) 102 cnputc(c); 103 } 104 105 /* 106 * Delete N characters, forward or backward 107 */ 108 #define DEL_FWD 0 109 #define DEL_BWD 1 110 void 111 db_delete(n, bwd) 112 int n; 113 int bwd; 114 { 115 register char *p; 116 117 if (bwd) { 118 db_lc -= n; 119 db_putnchars(BACKUP, n); 120 } 121 for (p = db_lc; p < db_le-n; p++) { 122 *p = *(p+n); 123 cnputc(*p); 124 } 125 db_putnchars(BLANK, n); 126 db_putnchars(BACKUP, db_le - db_lc); 127 db_le -= n; 128 } 129 130 /* returns TRUE at end-of-line */ 131 int 132 db_inputchar(c) 133 int c; 134 { 135 switch (c) { 136 case CTRL('b'): 137 /* back up one character */ 138 if (db_lc > db_lbuf_start) { 139 cnputc(BACKUP); 140 db_lc--; 141 } 142 break; 143 case CTRL('f'): 144 /* forward one character */ 145 if (db_lc < db_le) { 146 cnputc(*db_lc); 147 db_lc++; 148 } 149 break; 150 case CTRL('a'): 151 /* beginning of line */ 152 while (db_lc > db_lbuf_start) { 153 cnputc(BACKUP); 154 db_lc--; 155 } 156 break; 157 case CTRL('e'): 158 /* end of line */ 159 while (db_lc < db_le) { 160 cnputc(*db_lc); 161 db_lc++; 162 } 163 break; 164 case CTRL('h'): 165 case 0177: 166 /* erase previous character */ 167 if (db_lc > db_lbuf_start) 168 db_delete(1, DEL_BWD); 169 break; 170 case CTRL('d'): 171 /* erase next character */ 172 if (db_lc < db_le) 173 db_delete(1, DEL_FWD); 174 break; 175 case CTRL('k'): 176 /* delete to end of line */ 177 if (db_lc < db_le) 178 db_delete(db_le - db_lc, DEL_FWD); 179 break; 180 case CTRL('t'): 181 /* twiddle last 2 characters */ 182 if (db_lc >= db_lbuf_start + 2) { 183 c = db_lc[-2]; 184 db_lc[-2] = db_lc[-1]; 185 db_lc[-1] = c; 186 cnputc(BACKUP); 187 cnputc(BACKUP); 188 cnputc(db_lc[-2]); 189 cnputc(db_lc[-1]); 190 } 191 break; 192 case CTRL('r'): 193 db_putstring("^R\n", 3); 194 if (db_le > db_lbuf_start) { 195 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 196 db_putnchars(BACKUP, db_le - db_lc); 197 } 198 break; 199 case '\n': 200 case '\r': 201 *db_le++ = c; 202 return (1); 203 default: 204 if (db_le == db_lbuf_end) { 205 cnputc('\007'); 206 } 207 else if (c >= ' ' && c <= '~') { 208 register char *p; 209 210 for (p = db_le; p > db_lc; p--) 211 *p = *(p-1); 212 *db_lc++ = c; 213 db_le++; 214 cnputc(c); 215 db_putstring(db_lc, db_le - db_lc); 216 db_putnchars(BACKUP, db_le - db_lc); 217 } 218 break; 219 } 220 return (0); 221 } 222 223 int 224 db_readline(lstart, lsize) 225 char * lstart; 226 int lsize; 227 { 228 db_force_whitespace(); /* synch output position */ 229 230 db_lbuf_start = lstart; 231 db_lbuf_end = lstart + lsize; 232 db_lc = lstart; 233 db_le = lstart; 234 235 while (!db_inputchar(cngetc())) 236 continue; 237 238 db_putchar('\n'); /* synch output position */ 239 240 *db_le = 0; 241 return (db_le - db_lbuf_start); 242 } 243 244 void 245 db_check_interrupt() 246 { 247 register int c; 248 249 c = cnmaygetc(); 250 switch (c) { 251 case -1: /* no character */ 252 return; 253 254 case CTRL('c'): 255 db_error((char *)0); 256 /*NOTREACHED*/ 257 258 case CTRL('s'): 259 do { 260 c = cnmaygetc(); 261 if (c == CTRL('c')) 262 db_error((char *)0); 263 } while (c != CTRL('q')); 264 break; 265 266 default: 267 /* drop on floor */ 268 break; 269 } 270 } 271 272 cnmaygetc () 273 { 274 return (-1); 275 } 276 277 /* called from kdb_trap in db_interface.c */ 278 cnpollc (flag) 279 { 280 } 281
Indexes created Thu Oct 02 14:10:14 GMT 2025