readline.c

   1 /*
   2  * QEMU readline utility
   3  *
   4  * Copyright (c) 2003-2004 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "vl.h"
  25
  26 #define TERM_CMD_BUF_SIZE 4095
  27 #define TERM_MAX_CMDS 64
  28 #define NB_COMPLETIONS_MAX 256
  29
  30 #define IS_NORM 0
  31 #define IS_ESC  1
  32 #define IS_CSI  2
  33
  34 #define printf do_not_use_printf
  35
  36 static char term_cmd_buf[TERM_CMD_BUF_SIZE + 1];
  37 static int term_cmd_buf_index;
  38 static int term_cmd_buf_size;
  39
  40 static char term_last_cmd_buf[TERM_CMD_BUF_SIZE + 1];
  41 static int term_last_cmd_buf_index;
  42 static int term_last_cmd_buf_size;
  43
  44 static int term_esc_state;
  45 static int term_esc_param;
  46
  47 static char *term_history[TERM_MAX_CMDS];
  48 static int term_hist_entry = -1;
  49
  50 static int nb_completions;
  51 int completion_index;
  52 static char *completions[NB_COMPLETIONS_MAX];
  53
  54 static ReadLineFunc *term_readline_func;
  55 static int term_is_password;
  56 static char term_prompt[256];
  57 static void *term_readline_opaque;
  58
  59 static void term_show_prompt2(void)
  60 {
  61     term_printf("%s", term_prompt);
  62     term_flush();
  63     term_last_cmd_buf_index = 0;
  64     term_last_cmd_buf_size = 0;
  65     term_esc_state = IS_NORM;
  66 }
  67
  68 static void term_show_prompt(void)
  69 {
  70     term_show_prompt2();
  71     term_cmd_buf_index = 0;
  72     term_cmd_buf_size = 0;
  73 }
  74
  75 /* update the displayed command line */
  76 static void term_update(void)
  77 {
  78     int i, delta, len;
  79
  80     if (term_cmd_buf_size != term_last_cmd_buf_size ||
  81         memcmp(term_cmd_buf, term_last_cmd_buf, term_cmd_buf_size) != 0) {
  82         for(i = 0; i < term_last_cmd_buf_index; i++) {
  83             term_printf("\033[D");
  84         }
  85         term_cmd_buf[term_cmd_buf_size] = '\0';
  86         if (term_is_password) {
  87             len = strlen(term_cmd_buf);
  88             for(i = 0; i < len; i++)
  89                 term_printf("*");
  90         } else {
  91             term_printf("%s", term_cmd_buf);
  92         }
  93         term_printf("\033[K");
  94         memcpy(term_last_cmd_buf, term_cmd_buf, term_cmd_buf_size);
  95         term_last_cmd_buf_size = term_cmd_buf_size;
  96         term_last_cmd_buf_index = term_cmd_buf_size;
  97     }
  98     if (term_cmd_buf_index != term_last_cmd_buf_index) {
  99         delta = term_cmd_buf_index - term_last_cmd_buf_index;
 100         if (delta > 0) {
 101             for(i = 0;i < delta; i++) {
 102                 term_printf("\033[C");
 103             }
 104         } else {
 105             delta = -delta;
 106             for(i = 0;i < delta; i++) {
 107                 term_printf("\033[D");
 108             }
 109         }
 110         term_last_cmd_buf_index = term_cmd_buf_index;
 111     }
 112     term_flush();
 113 }
 114
 115 static void term_insert_char(int ch)
 116 {
 117     if (term_cmd_buf_index < TERM_CMD_BUF_SIZE) {
 118         memmove(term_cmd_buf + term_cmd_buf_index + 1,
 119                 term_cmd_buf + term_cmd_buf_index,
 120                 term_cmd_buf_size - term_cmd_buf_index);
 121         term_cmd_buf[term_cmd_buf_index] = ch;
 122         term_cmd_buf_size++;
 123         term_cmd_buf_index++;
 124     }
 125 }
 126
 127 static void term_backward_char(void)
 128 {
 129     if (term_cmd_buf_index > 0) {
 130         term_cmd_buf_index--;
 131     }
 132 }
 133
 134 static void term_forward_char(void)
 135 {
 136     if (term_cmd_buf_index < term_cmd_buf_size) {
 137         term_cmd_buf_index++;
 138     }
 139 }
 140
 141 static void term_delete_char(void)
 142 {
 143     if (term_cmd_buf_index < term_cmd_buf_size) {
 144         memmove(term_cmd_buf + term_cmd_buf_index,
 145                 term_cmd_buf + term_cmd_buf_index + 1,
 146                 term_cmd_buf_size - term_cmd_buf_index - 1);
 147         term_cmd_buf_size--;
 148     }
 149 }
 150
 151 static void term_backspace(void)
 152 {
 153     if (term_cmd_buf_index > 0) {
 154         term_backward_char();
 155         term_delete_char();
 156     }
 157 }
 158
 159 static void term_backword(void)
 160 {
 161     int start;
 162
 163     if (term_cmd_buf_index == 0 || term_cmd_buf_index > term_cmd_buf_size) {
 164         return;
 165     }
 166
 167     start = term_cmd_buf_index - 1;
 168
 169     /* find first word (backwards) */
 170     while (start > 0) {
 171         if (!isspace(term_cmd_buf[start])) {
 172             break;
 173         }
 174
 175         --start;
 176     }
 177
 178     /* find first space (backwards) */
 179     while (start > 0) {
 180         if (isspace(term_cmd_buf[start])) {
 181             ++start;
 182             break;
 183         }
 184
 185         --start;
 186     }
 187
 188     /* remove word */
 189     if (start < term_cmd_buf_index) {
 190         memmove(term_cmd_buf + start,
 191                 term_cmd_buf + term_cmd_buf_index,
 192                 term_cmd_buf_size - term_cmd_buf_index);
 193         term_cmd_buf_size -= term_cmd_buf_index - start;
 194         term_cmd_buf_index = start;
 195     }
 196 }
 197
 198 static void term_bol(void)
 199 {
 200     term_cmd_buf_index = 0;
 201 }
 202
 203 static void term_eol(void)
 204 {
 205     term_cmd_buf_index = term_cmd_buf_size;
 206 }
 207
 208 static void term_up_char(void)
 209 {
 210     int idx;
 211
 212     if (term_hist_entry == 0)
 213         return;
 214     if (term_hist_entry == -1) {
 215         /* Find latest entry */
 216         for (idx = 0; idx < TERM_MAX_CMDS; idx++) {
 217             if (term_history[idx] == NULL)
 218                 break;
 219         }
 220         term_hist_entry = idx;
 221     }
 222     term_hist_entry--;
 223     if (term_hist_entry >= 0) {
 224         pstrcpy(term_cmd_buf, sizeof(term_cmd_buf),
 225                 term_history[term_hist_entry]);
 226         term_cmd_buf_index = term_cmd_buf_size = strlen(term_cmd_buf);
 227     }
 228 }
 229
 230 static void term_down_char(void)
 231 {
 232     if (term_hist_entry == TERM_MAX_CMDS - 1 || term_hist_entry == -1)
 233         return;
 234     if (term_history[++term_hist_entry] != NULL) {
 235         pstrcpy(term_cmd_buf, sizeof(term_cmd_buf),
 236                 term_history[term_hist_entry]);
 237     } else {
 238         term_hist_entry = -1;
 239     }
 240     term_cmd_buf_index = term_cmd_buf_size = strlen(term_cmd_buf);
 241 }
 242
 243 static void term_hist_add(const char *cmdline)
 244 {
 245     char *hist_entry, *new_entry;
 246     int idx;
 247
 248     if (cmdline[0] == '\0')
 249         return;
 250     new_entry = NULL;
 251     if (term_hist_entry != -1) {
 252         /* We were editing an existing history entry: replace it */
 253         hist_entry = term_history[term_hist_entry];
 254         idx = term_hist_entry;
 255         if (strcmp(hist_entry, cmdline) == 0) {
 256             goto same_entry;
 257         }
 258     }
 259     /* Search cmdline in history buffers */
 260     for (idx = 0; idx < TERM_MAX_CMDS; idx++) {
 261         hist_entry = term_history[idx];
 262         if (hist_entry == NULL)
 263             break;
 264         if (strcmp(hist_entry, cmdline) == 0) {
 265         same_entry:
 266             new_entry = hist_entry;
 267             /* Put this entry at the end of history */
 268             memmove(&term_history[idx], &term_history[idx + 1],
 269                     &term_history[TERM_MAX_CMDS] - &term_history[idx + 1]);
 270             term_history[TERM_MAX_CMDS - 1] = NULL;
 271             for (; idx < TERM_MAX_CMDS; idx++) {
 272                 if (term_history[idx] == NULL)
 273                     break;
 274             }
 275             break;
 276         }
 277     }
 278     if (idx == TERM_MAX_CMDS) {
 279         /* Need to get one free slot */
 280         free(term_history[0]);
 281         memcpy(term_history, &term_history[1],
 282                &term_history[TERM_MAX_CMDS] - &term_history[1]);
 283         term_history[TERM_MAX_CMDS - 1] = NULL;
 284         idx = TERM_MAX_CMDS - 1;
 285     }
 286     if (new_entry == NULL)
 287         new_entry = strdup(cmdline);
 288     term_history[idx] = new_entry;
 289     term_hist_entry = -1;
 290 }
 291
 292 /* completion support */
 293
 294 void add_completion(const char *str)
 295 {
 296     if (nb_completions < NB_COMPLETIONS_MAX) {
 297         completions[nb_completions++] = qemu_strdup(str);
 298     }
 299 }
 300
 301 static void term_completion(void)
 302 {
 303     int len, i, j, max_width, nb_cols, max_prefix;
 304     char *cmdline;
 305
 306     nb_completions = 0;
 307
 308     cmdline = qemu_malloc(term_cmd_buf_index + 1);
 309     if (!cmdline)
 310         return;
 311     memcpy(cmdline, term_cmd_buf, term_cmd_buf_index);
 312     cmdline[term_cmd_buf_index] = '\0';
 313     readline_find_completion(cmdline);
 314     qemu_free(cmdline);
 315
 316     /* no completion found */
 317     if (nb_completions <= 0)
 318         return;
 319     if (nb_completions == 1) {
 320         len = strlen(completions[0]);
 321         for(i = completion_index; i < len; i++) {
 322             term_insert_char(completions[0][i]);
 323         }
 324         /* extra space for next argument. XXX: make it more generic */
 325         if (len > 0 && completions[0][len - 1] != '/')
 326             term_insert_char(' ');
 327     } else {
 328         term_printf("\n");
 329         max_width = 0;
 330         max_prefix = 0;
 331         for(i = 0; i < nb_completions; i++) {
 332             len = strlen(completions[i]);
 333             if (i==0) {
 334                 max_prefix = len;
 335             } else {
 336                 if (len < max_prefix)
 337                     max_prefix = len;
 338                 for(j=0; j<max_prefix; j++) {
 339                     if (completions[i][j] != completions[0][j])
 340                         max_prefix = j;
 341                 }
 342             }
 343             if (len > max_width)
 344                 max_width = len;
 345         }
 346         if (max_prefix > 0)
 347             for(i = completion_index; i < max_prefix; i++) {
 348                 term_insert_char(completions[0][i]);
 349             }
 350         max_width += 2;
 351         if (max_width < 10)
 352             max_width = 10;
 353         else if (max_width > 80)
 354             max_width = 80;
 355         nb_cols = 80 / max_width;
 356         j = 0;
 357         for(i = 0; i < nb_completions; i++) {
 358             term_printf("%-*s", max_width, completions[i]);
 359             if (++j == nb_cols || i == (nb_completions - 1)) {
 360                 term_printf("\n");
 361                 j = 0;
 362             }
 363         }
 364         term_show_prompt2();
 365     }
 366 }
 367
 368 /* return true if command handled */
 369 void readline_handle_byte(int ch)
 370 {
 371     switch(term_esc_state) {
 372     case IS_NORM:
 373         switch(ch) {
 374         case 1:
 375             term_bol();
 376             break;
 377         case 4:
 378             term_delete_char();
 379             break;
 380         case 5:
 381             term_eol();
 382             break;
 383         case 9:
 384             term_completion();
 385             break;
 386         case 10:
 387         case 13:
 388             term_cmd_buf[term_cmd_buf_size] = '\0';
 389             if (!term_is_password)
 390                 term_hist_add(term_cmd_buf);
 391             term_printf("\n");
 392             term_cmd_buf_index = 0;
 393             term_cmd_buf_size = 0;
 394             term_last_cmd_buf_index = 0;
 395             term_last_cmd_buf_size = 0;
 396             /* NOTE: readline_start can be called here */
 397             term_readline_func(term_readline_opaque, term_cmd_buf);
 398             break;
 399         case 23:
 400             /* ^W */
 401             term_backword();
 402             break;
 403         case 27:
 404             term_esc_state = IS_ESC;
 405             break;
 406         case 127:
 407         case 8:
 408             term_backspace();
 409             break;
 410         case 155:
 411             term_esc_state = IS_CSI;
 412             break;
 413         default:
 414             if (ch >= 32) {
 415                 term_insert_char(ch);
 416             }
 417             break;
 418         }
 419         break;
 420     case IS_ESC:
 421         if (ch == '[') {
 422             term_esc_state = IS_CSI;
 423             term_esc_param = 0;
 424         } else {
 425             term_esc_state = IS_NORM;
 426         }
 427         break;
 428     case IS_CSI:
 429         switch(ch) {
 430         case 'A':
 431         case 'F':
 432             term_up_char();
 433             break;
 434         case 'B':
 435         case 'E':
 436             term_down_char();
 437             break;
 438         case 'D':
 439             term_backward_char();
 440             break;
 441         case 'C':
 442             term_forward_char();
 443             break;
 444         case '0' ... '9':
 445             term_esc_param = term_esc_param * 10 + (ch - '0');
 446             goto the_end;
 447         case '~':
 448             switch(term_esc_param) {
 449             case 1:
 450                 term_bol();
 451                 break;
 452             case 3:
 453                 term_delete_char();
 454                 break;
 455             case 4:
 456                 term_eol();
 457                 break;
 458             }
 459             break;
 460         default:
 461             break;
 462         }
 463         term_esc_state = IS_NORM;
 464     the_end:
 465         break;
 466     }
 467     term_update();
 468 }
 469
 470 void readline_start(const char *prompt, int is_password,
 471                     ReadLineFunc *readline_func, void *opaque)
 472 {
 473     pstrcpy(term_prompt, sizeof(term_prompt), prompt);
 474     term_readline_func = readline_func;
 475     term_readline_opaque = opaque;
 476     term_is_password = is_password;
 477     term_show_prompt();
 478 }
 479
 480 const char *readline_get_history(unsigned int index)
 481 {
 482     if (index >= TERM_MAX_CMDS)
 483         return NULL;
 484     return term_history[index];
 485 }
 486
 487