db_input.c revision 12734
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 * $Id: db_input.c,v 1.11 1995/12/10 13:32:37 phk Exp $ 27 */ 28 29/* 30 * Author: David B. Golub, Carnegie Mellon University 31 * Date: 7/90 32 */ 33 34#include <sys/param.h> 35#include <sys/systm.h> 36 37#include <machine/cons.h> 38 39#include <ddb/ddb.h> 40#include <ddb/db_output.h> 41 42/* 43 * Character input and editing. 44 */ 45 46/* 47 * We don't track output position while editing input, 48 * since input always ends with a new-line. We just 49 * reset the line position at the end. 50 */ 51static char * db_lbuf_start; /* start of input line buffer */ 52static char * db_lbuf_end; /* end of input line buffer */ 53static char * db_lc; /* current character */ 54static char * db_le; /* one past last character */ 55 56#define CTRL(c) ((c) & 0x1f) 57#define isspace(c) ((c) == ' ' || (c) == '\t') 58#define BLANK ' ' 59#define BACKUP '\b' 60 61static int cnmaygetc __P((void)); 62static void db_delete __P((int n, int bwd)); 63static int db_inputchar __P((int c)); 64static void db_putnchars __P((int c, int count)); 65static void db_putstring __P((char *s, int count)); 66 67void 68db_putstring(s, count) 69 char *s; 70 int count; 71{ 72 while (--count >= 0) 73 cnputc(*s++); 74} 75 76void 77db_putnchars(c, count) 78 int c; 79 int count; 80{ 81 while (--count >= 0) 82 cnputc(c); 83} 84 85/* 86 * Delete N characters, forward or backward 87 */ 88#define DEL_FWD 0 89#define DEL_BWD 1 90void 91db_delete(n, bwd) 92 int n; 93 int bwd; 94{ 95 register char *p; 96 97 if (bwd) { 98 db_lc -= n; 99 db_putnchars(BACKUP, n); 100 } 101 for (p = db_lc; p < db_le-n; p++) { 102 *p = *(p+n); 103 cnputc(*p); 104 } 105 db_putnchars(BLANK, n); 106 db_putnchars(BACKUP, db_le - db_lc); 107 db_le -= n; 108} 109 110/* returns TRUE at end-of-line */ 111int 112db_inputchar(c) 113 int c; 114{ 115 switch (c) { 116 case CTRL('b'): 117 /* back up one character */ 118 if (db_lc > db_lbuf_start) { 119 cnputc(BACKUP); 120 db_lc--; 121 } 122 break; 123 case CTRL('f'): 124 /* forward one character */ 125 if (db_lc < db_le) { 126 cnputc(*db_lc); 127 db_lc++; 128 } 129 break; 130 case CTRL('a'): 131 /* beginning of line */ 132 while (db_lc > db_lbuf_start) { 133 cnputc(BACKUP); 134 db_lc--; 135 } 136 break; 137 case CTRL('e'): 138 /* end of line */ 139 while (db_lc < db_le) { 140 cnputc(*db_lc); 141 db_lc++; 142 } 143 break; 144 case CTRL('h'): 145 case 0177: 146 /* erase previous character */ 147 if (db_lc > db_lbuf_start) 148 db_delete(1, DEL_BWD); 149 break; 150 case CTRL('d'): 151 /* erase next character */ 152 if (db_lc < db_le) 153 db_delete(1, DEL_FWD); 154 break; 155 case CTRL('k'): 156 /* delete to end of line */ 157 if (db_lc < db_le) 158 db_delete(db_le - db_lc, DEL_FWD); 159 break; 160 case CTRL('t'): 161 /* twiddle last 2 characters */ 162 if (db_lc >= db_lbuf_start + 2) { 163 c = db_lc[-2]; 164 db_lc[-2] = db_lc[-1]; 165 db_lc[-1] = c; 166 cnputc(BACKUP); 167 cnputc(BACKUP); 168 cnputc(db_lc[-2]); 169 cnputc(db_lc[-1]); 170 } 171 break; 172 case CTRL('r'): 173 db_putstring("^R\n", 3); 174 if (db_le > db_lbuf_start) { 175 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 176 db_putnchars(BACKUP, db_le - db_lc); 177 } 178 break; 179 case '\n': 180 case '\r': 181 *db_le++ = c; 182 return (1); 183 default: 184 if (db_le == db_lbuf_end) { 185 cnputc('\007'); 186 } 187 else if (c >= ' ' && c <= '~') { 188 register char *p; 189 190 for (p = db_le; p > db_lc; p--) 191 *p = *(p-1); 192 *db_lc++ = c; 193 db_le++; 194 cnputc(c); 195 db_putstring(db_lc, db_le - db_lc); 196 db_putnchars(BACKUP, db_le - db_lc); 197 } 198 break; 199 } 200 return (0); 201} 202 203int 204cnmaygetc() 205{ 206 return (-1); 207} 208 209int 210db_readline(lstart, lsize) 211 char * lstart; 212 int lsize; 213{ 214 db_force_whitespace(); /* synch output position */ 215 216 db_lbuf_start = lstart; 217 db_lbuf_end = lstart + lsize; 218 db_lc = lstart; 219 db_le = lstart; 220 221 while (!db_inputchar(cngetc())) 222 continue; 223 224 db_putchar('\n'); /* synch output position */ 225 226 *db_le = 0; 227 return (db_le - db_lbuf_start); 228} 229 230void 231db_check_interrupt() 232{ 233 register int c; 234 235 c = cnmaygetc(); 236 switch (c) { 237 case -1: /* no character */ 238 return; 239 240 case CTRL('c'): 241 db_error((char *)0); 242 /*NOTREACHED*/ 243 244 case CTRL('s'): 245 do { 246 c = cnmaygetc(); 247 if (c == CTRL('c')) 248 db_error((char *)0); 249 } while (c != CTRL('q')); 250 break; 251 252 default: 253 /* drop on floor */ 254 break; 255 } 256} 257 258/* called from kdb_trap in db_interface.c */ 259void 260cnpollc (flag) 261 int flag; 262{ 263} 264