db_input.c revision 1.1
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 * HISTORY 28 * $Log: db_input.c,v $ 29 * Revision 1.1 1993/03/21 09:45:37 cgd 30 * Initial revision 31 * 32 * Revision 1.1 1992/03/25 21:45:10 pace 33 * Initial revision 34 * 35 * Revision 2.4 91/02/14 14:41:53 mrt 36 * Add input line editing. 37 * [90/11/11 dbg] 38 * 39 * Revision 2.3 91/02/05 17:06:32 mrt 40 * Changed to new Mach copyright 41 * [91/01/31 16:18:13 mrt] 42 * 43 * Revision 2.2 90/08/27 21:51:03 dbg 44 * Reduce lint. 45 * [90/08/07 dbg] 46 * Created. 47 * [90/07/25 dbg] 48 * 49 */ 50 /* 51 * Author: David B. Golub, Carnegie Mellon University 52 * Date: 7/90 53 */ 54 55 #include "param.h" 56 #include "proc.h" 57 #include <ddb/db_output.h> 58 59 /* 60 * Character input and editing. 61 */ 62 63 /* 64 * We don't track output position while editing input, 65 * since input always ends with a new-line. We just 66 * reset the line position at the end. 67 */ 68 char * db_lbuf_start; /* start of input line buffer */ 69 char * db_lbuf_end; /* end of input line buffer */ 70 char * db_lc; /* current character */ 71 char * db_le; /* one past last character */ 72 73 #define CTRL(c) ((c) & 0x1f) 74 #define isspace(c) ((c) == ' ' || (c) == '\t') 75 #define BLANK ' ' 76 #define BACKUP '\b' 77 78 void 79 db_putstring(s, count) 80 char *s; 81 int count; 82 { 83 while (--count >= 0) 84 cnputc(*s++); 85 } 86 87 void 88 db_putnchars(c, count) 89 int c; 90 int count; 91 { 92 while (--count >= 0) 93 cnputc(c); 94 } 95 96 /* 97 * Delete N characters, forward or backward 98 */ 99 #define DEL_FWD 0 100 #define DEL_BWD 1 101 void 102 db_delete(n, bwd) 103 int n; 104 int bwd; 105 { 106 register char *p; 107 108 if (bwd) { 109 db_lc -= n; 110 db_putnchars(BACKUP, n); 111 } 112 for (p = db_lc; p < db_le-n; p++) { 113 *p = *(p+n); 114 cnputc(*p); 115 } 116 db_putnchars(BLANK, n); 117 db_putnchars(BACKUP, db_le - db_lc); 118 db_le -= n; 119 } 120 121 /* returns TRUE at end-of-line */ 122 int 123 db_inputchar(c) 124 int c; 125 { 126 switch (c) { 127 case CTRL('b'): 128 /* back up one character */ 129 if (db_lc > db_lbuf_start) { 130 cnputc(BACKUP); 131 db_lc--; 132 } 133 break; 134 case CTRL('f'): 135 /* forward one character */ 136 if (db_lc < db_le) { 137 cnputc(*db_lc); 138 db_lc++; 139 } 140 break; 141 case CTRL('a'): 142 /* beginning of line */ 143 while (db_lc > db_lbuf_start) { 144 cnputc(BACKUP); 145 db_lc--; 146 } 147 break; 148 case CTRL('e'): 149 /* end of line */ 150 while (db_lc < db_le) { 151 cnputc(*db_lc); 152 db_lc++; 153 } 154 break; 155 case CTRL('h'): 156 case 0177: 157 /* erase previous character */ 158 if (db_lc > db_lbuf_start) 159 db_delete(1, DEL_BWD); 160 break; 161 case CTRL('d'): 162 /* erase next character */ 163 if (db_lc < db_le) 164 db_delete(1, DEL_FWD); 165 break; 166 case CTRL('k'): 167 /* delete to end of line */ 168 if (db_lc < db_le) 169 db_delete(db_le - db_lc, DEL_FWD); 170 break; 171 case CTRL('t'): 172 /* twiddle last 2 characters */ 173 if (db_lc >= db_lbuf_start + 2) { 174 c = db_lc[-2]; 175 db_lc[-2] = db_lc[-1]; 176 db_lc[-1] = c; 177 cnputc(BACKUP); 178 cnputc(BACKUP); 179 cnputc(db_lc[-2]); 180 cnputc(db_lc[-1]); 181 } 182 break; 183 case CTRL('r'): 184 db_putstring("^R\n", 3); 185 if (db_le > db_lbuf_start) { 186 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 187 db_putnchars(BACKUP, db_le - db_lc); 188 } 189 break; 190 case '\n': 191 case '\r': 192 *db_le++ = c; 193 return (1); 194 default: 195 if (db_le == db_lbuf_end) { 196 cnputc('\007'); 197 } 198 else if (c >= ' ' && c <= '~') { 199 register char *p; 200 201 for (p = db_le; p > db_lc; p--) 202 *p = *(p-1); 203 *db_lc++ = c; 204 db_le++; 205 cnputc(c); 206 db_putstring(db_lc, db_le - db_lc); 207 db_putnchars(BACKUP, db_le - db_lc); 208 } 209 break; 210 } 211 return (0); 212 } 213 214 int 215 db_readline(lstart, lsize) 216 char * lstart; 217 int lsize; 218 { 219 db_force_whitespace(); /* synch output position */ 220 221 db_lbuf_start = lstart; 222 db_lbuf_end = lstart + lsize; 223 db_lc = lstart; 224 db_le = lstart; 225 226 while (!db_inputchar(cngetc())) 227 continue; 228 229 db_putchar('\n'); /* synch output position */ 230 231 *db_le = 0; 232 return (db_le - db_lbuf_start); 233 } 234 235 void 236 db_check_interrupt() 237 { 238 register int c; 239 240 c = cnmaygetc(); 241 switch (c) { 242 case -1: /* no character */ 243 return; 244 245 case CTRL('c'): 246 db_error((char *)0); 247 /*NOTREACHED*/ 248 249 case CTRL('s'): 250 do { 251 c = cnmaygetc(); 252 if (c == CTRL('c')) 253 db_error((char *)0); 254 } while (c != CTRL('q')); 255 break; 256 257 default: 258 /* drop on floor */ 259 break; 260 } 261 } 262 263 cnmaygetc () 264 { 265 return (-1); 266 } 267 268 /* called from kdb_trap in db_interface.c */ 269 cnpollc (flag) 270 { 271 } 272
Indexes created Tue Sep 23 14:10:03 GMT 2025