util/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
  25 #include "qemu/osdep.h"
  26 #include "qemu/readline.h"
  27 #include "qemu/ctype.h"
  28 #include "qemu/cutils.h"
  29
  30 #define IS_NORM 0
  31 #define IS_ESC  1
  32 #define IS_CSI  2
  33 #define IS_SS3  3
  34
  35 void readline_show_prompt(ReadLineState *rs)
  36 {
  37     rs->printf_func(rs->opaque, "%s", rs->prompt);
  38     rs->flush_func(rs->opaque);
  39     rs->last_cmd_buf_index = 0;
  40     rs->last_cmd_buf_size = 0;
  41     rs->esc_state = IS_NORM;
  42 }
  43
  44 /* update the displayed command line */
  45 static void readline_update(ReadLineState *rs)
  46 {
  47     int i, delta, len;
  48
  49     if (rs->cmd_buf_size != rs->last_cmd_buf_size ||
  50         memcmp(rs->cmd_buf, rs->last_cmd_buf, rs->cmd_buf_size) != 0) {
  51         for (i = 0; i < rs->last_cmd_buf_index; i++) {
  52             rs->printf_func(rs->opaque, "\033[D");
  53         }
  54         rs->cmd_buf[rs->cmd_buf_size] = '\0';
  55         if (rs->read_password) {
  56             len = strlen(rs->cmd_buf);
  57             for (i = 0; i < len; i++) {
  58                 rs->printf_func(rs->opaque, "*");
  59             }
  60         } else {
  61             rs->printf_func(rs->opaque, "%s", rs->cmd_buf);
  62         }
  63         rs->printf_func(rs->opaque, "\033[K");
  64         memcpy(rs->last_cmd_buf, rs->cmd_buf, rs->cmd_buf_size);
  65         rs->last_cmd_buf_size = rs->cmd_buf_size;
  66         rs->last_cmd_buf_index = rs->cmd_buf_size;
  67     }
  68     if (rs->cmd_buf_index != rs->last_cmd_buf_index) {
  69         delta = rs->cmd_buf_index - rs->last_cmd_buf_index;
  70         if (delta > 0) {
  71             for (i = 0; i < delta; i++) {
  72                 rs->printf_func(rs->opaque, "\033[C");
  73             }
  74         } else {
  75             delta = -delta;
  76             for (i = 0; i < delta; i++) {
  77                 rs->printf_func(rs->opaque, "\033[D");
  78             }
  79         }
  80         rs->last_cmd_buf_index = rs->cmd_buf_index;
  81     }
  82     rs->flush_func(rs->opaque);
  83 }
  84
  85 static void readline_insert_char(ReadLineState *rs, int ch)
  86 {
  87     if (rs->cmd_buf_index < READLINE_CMD_BUF_SIZE) {
  88         memmove(rs->cmd_buf + rs->cmd_buf_index + 1,
  89                 rs->cmd_buf + rs->cmd_buf_index,
  90                 rs->cmd_buf_size - rs->cmd_buf_index);
  91         rs->cmd_buf[rs->cmd_buf_index] = ch;
  92         rs->cmd_buf_size++;
  93         rs->cmd_buf_index++;
  94     }
  95 }
  96
  97 static void readline_backward_char(ReadLineState *rs)
  98 {
  99     if (rs->cmd_buf_index > 0) {
 100         rs->cmd_buf_index--;
 101     }
 102 }
 103
 104 static void readline_forward_char(ReadLineState *rs)
 105 {
 106     if (rs->cmd_buf_index < rs->cmd_buf_size) {
 107         rs->cmd_buf_index++;
 108     }
 109 }
 110
 111 static void readline_delete_char(ReadLineState *rs)
 112 {
 113     if (rs->cmd_buf_index < rs->cmd_buf_size) {
 114         memmove(rs->cmd_buf + rs->cmd_buf_index,
 115                 rs->cmd_buf + rs->cmd_buf_index + 1,
 116                 rs->cmd_buf_size - rs->cmd_buf_index - 1);
 117         rs->cmd_buf_size--;
 118     }
 119 }
 120
 121 static void readline_backspace(ReadLineState *rs)
 122 {
 123     if (rs->cmd_buf_index > 0) {
 124         readline_backward_char(rs);
 125         readline_delete_char(rs);
 126     }
 127 }
 128
 129 static void readline_backword(ReadLineState *rs)
 130 {
 131     int start;
 132
 133     if (rs->cmd_buf_index == 0 || rs->cmd_buf_index > rs->cmd_buf_size) {
 134         return;
 135     }
 136
 137     start = rs->cmd_buf_index - 1;
 138
 139     /* find first word (backwards) */
 140     while (start > 0) {
 141         if (!qemu_isspace(rs->cmd_buf[start])) {
 142             break;
 143         }
 144
 145         --start;
 146     }
 147
 148     /* find first space (backwards) */
 149     while (start > 0) {
 150         if (qemu_isspace(rs->cmd_buf[start])) {
 151             ++start;
 152             break;
 153         }
 154
 155         --start;
 156     }
 157
 158     /* remove word */
 159     if (start < rs->cmd_buf_index) {
 160         memmove(rs->cmd_buf + start,
 161                 rs->cmd_buf + rs->cmd_buf_index,
 162                 rs->cmd_buf_size - rs->cmd_buf_index);
 163         rs->cmd_buf_size -= rs->cmd_buf_index - start;
 164         rs->cmd_buf_index = start;
 165     }
 166 }
 167
 168 static void readline_bol(ReadLineState *rs)
 169 {
 170     rs->cmd_buf_index = 0;
 171 }
 172
 173 static void readline_eol(ReadLineState *rs)
 174 {
 175     rs->cmd_buf_index = rs->cmd_buf_size;
 176 }
 177
 178 static void readline_up_char(ReadLineState *rs)
 179 {
 180     int idx;
 181
 182     if (rs->hist_entry == 0) {
 183         return;
 184     }
 185     if (rs->hist_entry == -1) {
 186         /* Find latest entry */
 187         for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
 188             if (rs->history[idx] == NULL) {
 189                 break;
 190             }
 191         }
 192         rs->hist_entry = idx;
 193     }
 194     rs->hist_entry--;
 195     if (rs->hist_entry >= 0) {
 196         pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
 197                 rs->history[rs->hist_entry]);
 198         rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
 199     }
 200 }
 201
 202 static void readline_down_char(ReadLineState *rs)
 203 {
 204     if (rs->hist_entry == -1) {
 205         return;
 206     }
 207     if (rs->hist_entry < READLINE_MAX_CMDS - 1 &&
 208         rs->history[++rs->hist_entry] != NULL) {
 209         pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
 210                 rs->history[rs->hist_entry]);
 211     } else {
 212         rs->cmd_buf[0] = 0;
 213         rs->hist_entry = -1;
 214     }
 215     rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
 216 }
 217
 218 static void readline_hist_add(ReadLineState *rs, const char *cmdline)
 219 {
 220     char *hist_entry, *new_entry;
 221     int idx;
 222
 223     if (cmdline[0] == '\0') {
 224         return;
 225     }
 226     new_entry = NULL;
 227     if (rs->hist_entry != -1) {
 228         /* We were editing an existing history entry: replace it */
 229         hist_entry = rs->history[rs->hist_entry];
 230         idx = rs->hist_entry;
 231         if (strcmp(hist_entry, cmdline) == 0) {
 232             goto same_entry;
 233         }
 234     }
 235     /* Search cmdline in history buffers */
 236     for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
 237         hist_entry = rs->history[idx];
 238         if (hist_entry == NULL) {
 239             break;
 240         }
 241         if (strcmp(hist_entry, cmdline) == 0) {
 242         same_entry:
 243             if (idx == READLINE_MAX_CMDS - 1) {
 244                 return;
 245             }
 246             new_entry = hist_entry;
 247             /* Put this entry at the end of history */
 248             memmove(&rs->history[idx], &rs->history[idx + 1],
 249                     (READLINE_MAX_CMDS - (idx + 1)) * sizeof(char *));
 250             rs->history[READLINE_MAX_CMDS - 1] = NULL;
 251             for (; idx < READLINE_MAX_CMDS; idx++) {
 252                 if (rs->history[idx] == NULL) {
 253                     break;
 254                 }
 255             }
 256             break;
 257         }
 258     }
 259     if (idx == READLINE_MAX_CMDS) {
 260         /* Need to get one free slot */
 261         g_free(rs->history[0]);
 262         memmove(rs->history, &rs->history[1],
 263                 (READLINE_MAX_CMDS - 1) * sizeof(char *));
 264         rs->history[READLINE_MAX_CMDS - 1] = NULL;
 265         idx = READLINE_MAX_CMDS - 1;
 266     }
 267     if (new_entry == NULL) {
 268         new_entry = g_strdup(cmdline);
 269     }
 270     rs->history[idx] = new_entry;
 271     rs->hist_entry = -1;
 272 }
 273
 274 static void readline_kill_line(ReadLineState *rs)
 275 {
 276     while (rs->cmd_buf_index > 0) {
 277         readline_backward_char(rs);
 278         readline_delete_char(rs);
 279     }
 280 }
 281
 282 /* completion support */
 283
 284 void readline_add_completion(ReadLineState *rs, const char *str)
 285 {
 286     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
 287         int i;
 288         for (i = 0; i < rs->nb_completions; i++) {
 289             if (!strcmp(rs->completions[i], str)) {
 290                 return;
 291             }
 292         }
 293         rs->completions[rs->nb_completions++] = g_strdup(str);
 294     }
 295 }
 296
 297 void readline_add_completion_of(ReadLineState *rs,
 298                                 const char *pfx, const char *str)
 299 {
 300     if (!strncmp(str, pfx, strlen(pfx))) {
 301         readline_add_completion(rs, str);
 302     }
 303 }
 304
 305 void readline_set_completion_index(ReadLineState *rs, int index)
 306 {
 307     rs->completion_index = index;
 308 }
 309
 310 static int completion_comp(const void *a, const void *b)
 311 {
 312     return strcmp(*(const char **) a, *(const char **) b);
 313 }
 314
 315 static void readline_completion(ReadLineState *rs)
 316 {
 317     int len, i, j, max_width, nb_cols, max_prefix;
 318     char *cmdline;
 319
 320     rs->nb_completions = 0;
 321
 322     cmdline = g_strndup(rs->cmd_buf, rs->cmd_buf_index);
 323     rs->completion_finder(rs->opaque, cmdline);
 324     g_free(cmdline);
 325
 326     /* no completion found */
 327     if (rs->nb_completions <= 0) {
 328         return;
 329     }
 330     if (rs->nb_completions == 1) {
 331         len = strlen(rs->completions[0]);
 332         for (i = rs->completion_index; i < len; i++) {
 333             readline_insert_char(rs, rs->completions[0][i]);
 334         }
 335         /* extra space for next argument. XXX: make it more generic */
 336         if (len > 0 && rs->completions[0][len - 1] != '/') {
 337             readline_insert_char(rs, ' ');
 338         }
 339     } else {
 340         qsort(rs->completions, rs->nb_completions, sizeof(char *),
 341               completion_comp);
 342         rs->printf_func(rs->opaque, "\n");
 343         max_width = 0;
 344         max_prefix = 0;
 345         for (i = 0; i < rs->nb_completions; i++) {
 346             len = strlen(rs->completions[i]);
 347             if (i == 0) {
 348                 max_prefix = len;
 349             } else {
 350                 if (len < max_prefix) {
 351                     max_prefix = len;
 352                 }
 353                 for (j = 0; j < max_prefix; j++) {
 354                     if (rs->completions[i][j] != rs->completions[0][j]) {
 355                         max_prefix = j;
 356                     }
 357                 }
 358             }
 359             if (len > max_width) {
 360                 max_width = len;
 361             }
 362         }
 363         if (max_prefix > 0)
 364             for (i = rs->completion_index; i < max_prefix; i++) {
 365                 readline_insert_char(rs, rs->completions[0][i]);
 366             }
 367         max_width += 2;
 368         if (max_width < 10) {
 369             max_width = 10;
 370         } else if (max_width > 80) {
 371             max_width = 80;
 372         }
 373         nb_cols = 80 / max_width;
 374         j = 0;
 375         for (i = 0; i < rs->nb_completions; i++) {
 376             rs->printf_func(rs->opaque, "%-*s", max_width, rs->completions[i]);
 377             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
 378                 rs->printf_func(rs->opaque, "\n");
 379                 j = 0;
 380             }
 381         }
 382         readline_show_prompt(rs);
 383     }
 384     for (i = 0; i < rs->nb_completions; i++) {
 385         g_free(rs->completions[i]);
 386     }
 387 }
 388
 389 static void readline_clear_screen(ReadLineState *rs)
 390 {
 391     rs->printf_func(rs->opaque, "\033[2J\033[1;1H");
 392     readline_show_prompt(rs);
 393 }
 394
 395 /* return true if command handled */
 396 void readline_handle_byte(ReadLineState *rs, int ch)
 397 {
 398     switch (rs->esc_state) {
 399     case IS_NORM:
 400         switch (ch) {
 401         case 1:
 402             readline_bol(rs);
 403             break;
 404         case 4:
 405             readline_delete_char(rs);
 406             break;
 407         case 5:
 408             readline_eol(rs);
 409             break;
 410         case 9:
 411             readline_completion(rs);
 412             break;
 413         case 12:
 414             readline_clear_screen(rs);
 415             break;
 416         case 10: /* fallthrough */
 417         case 13:
 418             rs->cmd_buf[rs->cmd_buf_size] = '\0';
 419             if (!rs->read_password) {
 420                 readline_hist_add(rs, rs->cmd_buf);
 421             }
 422             rs->printf_func(rs->opaque, "\n");
 423             rs->cmd_buf_index = 0;
 424             rs->cmd_buf_size = 0;
 425             rs->last_cmd_buf_index = 0;
 426             rs->last_cmd_buf_size = 0;
 427             rs->readline_func(rs->opaque, rs->cmd_buf, rs->readline_opaque);
 428             break;
 429         case 14:
 430             /* ^N Next line in history */
 431             readline_down_char(rs);
 432             break;
 433         case 16:
 434             /* ^P Prev line in history */
 435             readline_up_char(rs);
 436             break;
 437         case 21:
 438             /* ^U Kill backward from point to the beginning of the line. */
 439             readline_kill_line(rs);
 440             break;
 441         case 23:
 442             /* ^W */
 443             readline_backword(rs);
 444             break;
 445         case 27:
 446             rs->esc_state = IS_ESC;
 447             break;
 448         case 127: /* fallthrough */
 449         case 8:
 450             readline_backspace(rs);
 451             break;
 452         case 155:
 453             rs->esc_state = IS_CSI;
 454             break;
 455         default:
 456             if (ch >= 32) {
 457                 readline_insert_char(rs, ch);
 458             }
 459             break;
 460         }
 461         break;
 462     case IS_ESC:
 463         if (ch == '[') {
 464             rs->esc_state = IS_CSI;
 465             rs->esc_param = 0;
 466         } else if (ch == 'O') {
 467             rs->esc_state = IS_SS3;
 468             rs->esc_param = 0;
 469         } else {
 470             rs->esc_state = IS_NORM;
 471         }
 472         break;
 473     case IS_CSI:
 474         switch (ch) {
 475         case 'A': /* fallthrough */
 476         case 'F':
 477             readline_up_char(rs);
 478             break;
 479         case 'B': /* fallthrough */
 480         case 'E':
 481             readline_down_char(rs);
 482             break;
 483         case 'D':
 484             readline_backward_char(rs);
 485             break;
 486         case 'C':
 487             readline_forward_char(rs);
 488             break;
 489         case '0' ... '9':
 490             rs->esc_param = rs->esc_param * 10 + (ch - '0');
 491             goto the_end;
 492         case '~':
 493             switch (rs->esc_param) {
 494             case 1:
 495                 readline_bol(rs);
 496                 break;
 497             case 3:
 498                 readline_delete_char(rs);
 499                 break;
 500             case 4:
 501                 readline_eol(rs);
 502                 break;
 503             default:
 504                 break;
 505             }
 506             break;
 507         default:
 508             break;
 509         }
 510         rs->esc_state = IS_NORM;
 511         /* fallthrough */
 512     the_end:
 513         break;
 514     case IS_SS3:
 515         switch (ch) {
 516         case 'F':
 517             readline_eol(rs);
 518             break;
 519         case 'H':
 520             readline_bol(rs);
 521             break;
 522         default:
 523             break;
 524         }
 525         rs->esc_state = IS_NORM;
 526         break;
 527     default:
 528         break;
 529     }
 530     readline_update(rs);
 531 }
 532
 533 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
 534                     ReadLineFunc *readline_func, void *opaque)
 535 {
 536     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
 537     rs->readline_func = readline_func;
 538     rs->readline_opaque = opaque;
 539     rs->read_password = read_password;
 540     readline_restart(rs);
 541 }
 542
 543 void readline_restart(ReadLineState *rs)
 544 {
 545     rs->cmd_buf_index = 0;
 546     rs->cmd_buf_size = 0;
 547 }
 548
 549 const char *readline_get_history(ReadLineState *rs, unsigned int index)
 550 {
 551     if (index >= READLINE_MAX_CMDS) {
 552         return NULL;
 553     }
 554     return rs->history[index];
 555 }
 556
 557 void readline_free(ReadLineState *rs)
 558 {
 559     int i;
 560
 561     if (!rs) {
 562         return;
 563     }
 564     for (i = 0; i < READLINE_MAX_CMDS; i++) {
 565         g_free(rs->history[i]);
 566     }
 567     g_free(rs);
 568 }
 569
 570 ReadLineState *readline_init(ReadLinePrintfFunc *printf_func,
 571                              ReadLineFlushFunc *flush_func,
 572                              void *opaque,
 573                              ReadLineCompletionFunc *completion_finder)
 574 {
 575     ReadLineState *rs = g_new0(ReadLineState, 1);
 576
 577     rs->hist_entry = -1;
 578     rs->opaque = opaque;
 579     rs->printf_func = printf_func;
 580     rs->flush_func = flush_func;
 581     rs->completion_finder = completion_finder;
 582
 583     return rs;
 584 }