1 /* $NetBSD: db_input.c,v 1.7 1996/02/05 01:57:02 christos Exp $ */ 2 3 /* 4 * Mach Operating System 5 * Copyright (c) 1991,1990 Carnegie Mellon University 6 * All Rights Reserved. 7 * 8 * Permission to use, copy, modify and distribute this software and its 9 * documentation is hereby granted, provided that both the copyright 10 * notice and this permission notice appear in all copies of the 11 * software, derivative works or modified versions, and any portions 12 * thereof, and that both notices appear in supporting documentation. 13 * 14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 17 * 18 * Carnegie Mellon requests users of this software to return to 19 * 20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 21 * School of Computer Science 22 * Carnegie Mellon University 23 * Pittsburgh PA 15213-3890 24 * 25 * any improvements or extensions that they make and grant Carnegie the 26 * rights to redistribute these changes. 27 * 28 * Author: David B. Golub, Carnegie Mellon University 29 * Date: 7/90 30 */ 31 32 #include <sys/param.h> 33 #include <sys/proc.h> 34 35 #include <machine/db_machdep.h> 36 37 #include <ddb/db_output.h> 38 #include <ddb/db_command.h> 39 #include <ddb/db_sym.h> 40 #include <ddb/db_extern.h> 41 42 #include <dev/cons.h> 43 44 /* 45 * Character input and editing. 46 */ 47 48 /* 49 * We don't track output position while editing input, 50 * since input always ends with a new-line. We just 51 * reset the line position at the end. 52 */ 53 char * db_lbuf_start; /* start of input line buffer */ 54 char * db_lbuf_end; /* end of input line buffer */ 55 char * db_lc; /* current character */ 56 char * db_le; /* one past last character */ 57 58 #define CTRL(c) ((c) & 0x1f) 59 #define isspace(c) ((c) == ' ' || (c) == '\t') 60 #define BLANK ' ' 61 #define BACKUP '\b' 62 63 static int cnmaygetc __P((void)); 64 65 void 66 db_putstring(s, count) 67 char *s; 68 int count; 69 { 70 while (--count >= 0) 71 cnputc(*s++); 72 } 73 74 void 75 db_putnchars(c, count) 76 int c; 77 int count; 78 { 79 while (--count >= 0) 80 cnputc(c); 81 } 82 83 /* 84 * Delete N characters, forward or backward 85 */ 86 #define DEL_FWD 0 87 #define DEL_BWD 1 88 void 89 db_delete(n, bwd) 90 int n; 91 int bwd; 92 { 93 register char *p; 94 95 if (bwd) { 96 db_lc -= n; 97 db_putnchars(BACKUP, n); 98 } 99 for (p = db_lc; p < db_le-n; p++) { 100 *p = *(p+n); 101 cnputc(*p); 102 } 103 db_putnchars(BLANK, n); 104 db_putnchars(BACKUP, db_le - db_lc); 105 db_le -= n; 106 } 107 108 /* returns TRUE at end-of-line */ 109 int 110 db_inputchar(c) 111 int c; 112 { 113 switch (c) { 114 case CTRL('b'): 115 /* back up one character */ 116 if (db_lc > db_lbuf_start) { 117 cnputc(BACKUP); 118 db_lc--; 119 } 120 break; 121 case CTRL('f'): 122 /* forward one character */ 123 if (db_lc < db_le) { 124 cnputc(*db_lc); 125 db_lc++; 126 } 127 break; 128 case CTRL('a'): 129 /* beginning of line */ 130 while (db_lc > db_lbuf_start) { 131 cnputc(BACKUP); 132 db_lc--; 133 } 134 break; 135 case CTRL('e'): 136 /* end of line */ 137 while (db_lc < db_le) { 138 cnputc(*db_lc); 139 db_lc++; 140 } 141 break; 142 case CTRL('h'): 143 case 0177: 144 /* erase previous character */ 145 if (db_lc > db_lbuf_start) 146 db_delete(1, DEL_BWD); 147 break; 148 case CTRL('d'): 149 /* erase next character */ 150 if (db_lc < db_le) 151 db_delete(1, DEL_FWD); 152 break; 153 case CTRL('k'): 154 /* delete to end of line */ 155 if (db_lc < db_le) 156 db_delete(db_le - db_lc, DEL_FWD); 157 break; 158 case CTRL('t'): 159 /* twiddle last 2 characters */ 160 if (db_lc >= db_lbuf_start + 2) { 161 c = db_lc[-2]; 162 db_lc[-2] = db_lc[-1]; 163 db_lc[-1] = c; 164 cnputc(BACKUP); 165 cnputc(BACKUP); 166 cnputc(db_lc[-2]); 167 cnputc(db_lc[-1]); 168 } 169 break; 170 case CTRL('r'): 171 db_putstring("^R\n", 3); 172 if (db_le > db_lbuf_start) { 173 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 174 db_putnchars(BACKUP, db_le - db_lc); 175 } 176 break; 177 case '\n': 178 case '\r': 179 *db_le++ = c; 180 return (1); 181 default: 182 if (db_le == db_lbuf_end) { 183 cnputc('\007'); 184 } 185 else if (c >= ' ' && c <= '~') { 186 register char *p; 187 188 for (p = db_le; p > db_lc; p--) 189 *p = *(p-1); 190 *db_lc++ = c; 191 db_le++; 192 cnputc(c); 193 db_putstring(db_lc, db_le - db_lc); 194 db_putnchars(BACKUP, db_le - db_lc); 195 } 196 break; 197 } 198 return (0); 199 } 200 201 int 202 db_readline(lstart, lsize) 203 char * lstart; 204 int lsize; 205 { 206 db_force_whitespace(); /* synch output position */ 207 208 db_lbuf_start = lstart; 209 db_lbuf_end = lstart + lsize; 210 db_lc = lstart; 211 db_le = lstart; 212 213 while (!db_inputchar(cngetc())) 214 continue; 215 216 db_putchar('\n'); /* synch output position */ 217 218 *db_le = 0; 219 return (db_le - db_lbuf_start); 220 } 221 222 void 223 db_check_interrupt() 224 { 225 register int c; 226 227 c = cnmaygetc(); 228 switch (c) { 229 case -1: /* no character */ 230 return; 231 232 case CTRL('c'): 233 db_error((char *)0); 234 /*NOTREACHED*/ 235 236 case CTRL('s'): 237 do { 238 c = cnmaygetc(); 239 if (c == CTRL('c')) { 240 db_error((char *)0); 241 /*NOTREACHED*/ 242 } 243 } while (c != CTRL('q')); 244 break; 245 246 default: 247 /* drop on floor */ 248 break; 249 } 250 } 251 252 static int 253 cnmaygetc () 254 { 255 return (-1); 256 } 257