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 /* completion support */
 275
 276 void readline_add_completion(ReadLineState *rs, const char *str)
 277 {
 278     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
 279         int i;
 280         for (i = 0; i < rs->nb_completions; i++) {
 281             if (!strcmp(rs->completions[i], str)) {
 282                 return;
 283             }
 284         }
 285         rs->completions[rs->nb_completions++] = g_strdup(str);
 286     }
 287 }
 288
 289 void readline_add_completion_of(ReadLineState *rs,
 290                                 const char *pfx, const char *str)
 291 {
 292     if (!strncmp(str, pfx, strlen(pfx))) {
 293         readline_add_completion(rs, str);
 294     }
 295 }
 296
 297 void readline_set_completion_index(ReadLineState *rs, int index)
 298 {
 299     rs->completion_index = index;
 300 }
 301
 302 static int completion_comp(const void *a, const void *b)
 303 {
 304     return strcmp(*(const char **) a, *(const char **) b);
 305 }
 306
 307 static void readline_completion(ReadLineState *rs)
 308 {
 309     int len, i, j, max_width, nb_cols, max_prefix;
 310     char *cmdline;
 311
 312     rs->nb_completions = 0;
 313
 314     cmdline = g_strndup(rs->cmd_buf, rs->cmd_buf_index);
 315     rs->completion_finder(rs->opaque, cmdline);
 316     g_free(cmdline);
 317
 318     /* no completion found */
 319     if (rs->nb_completions <= 0) {
 320         return;
 321     }
 322     if (rs->nb_completions == 1) {
 323         len = strlen(rs->completions[0]);
 324         for (i = rs->completion_index; i < len; i++) {
 325             readline_insert_char(rs, rs->completions[0][i]);
 326         }
 327         /* extra space for next argument. XXX: make it more generic */
 328         if (len > 0 && rs->completions[0][len - 1] != '/') {
 329             readline_insert_char(rs, ' ');
 330         }
 331     } else {
 332         qsort(rs->completions, rs->nb_completions, sizeof(char *),
 333               completion_comp);
 334         rs->printf_func(rs->opaque, "\n");
 335         max_width = 0;
 336         max_prefix = 0;
 337         for (i = 0; i < rs->nb_completions; i++) {
 338             len = strlen(rs->completions[i]);
 339             if (i == 0) {
 340                 max_prefix = len;
 341             } else {
 342                 if (len < max_prefix) {
 343                     max_prefix = len;
 344                 }
 345                 for (j = 0; j < max_prefix; j++) {
 346                     if (rs->completions[i][j] != rs->completions[0][j]) {
 347                         max_prefix = j;
 348                     }
 349                 }
 350             }
 351             if (len > max_width) {
 352                 max_width = len;
 353             }
 354         }
 355         if (max_prefix > 0)
 356             for (i = rs->completion_index; i < max_prefix; i++) {
 357                 readline_insert_char(rs, rs->completions[0][i]);
 358             }
 359         max_width += 2;
 360         if (max_width < 10) {
 361             max_width = 10;
 362         } else if (max_width > 80) {
 363             max_width = 80;
 364         }
 365         nb_cols = 80 / max_width;
 366         j = 0;
 367         for (i = 0; i < rs->nb_completions; i++) {
 368             rs->printf_func(rs->opaque, "%-*s", max_width, rs->completions[i]);
 369             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
 370                 rs->printf_func(rs->opaque, "\n");
 371                 j = 0;
 372             }
 373         }
 374         readline_show_prompt(rs);
 375     }
 376     for (i = 0; i < rs->nb_completions; i++) {
 377         g_free(rs->completions[i]);
 378     }
 379 }
 380
 381 static void readline_clear_screen(ReadLineState *rs)
 382 {
 383     rs->printf_func(rs->opaque, "\033[2J\033[1;1H");
 384     readline_show_prompt(rs);
 385 }
 386
 387 /* return true if command handled */
 388 void readline_handle_byte(ReadLineState *rs, int ch)
 389 {
 390     switch (rs->esc_state) {
 391     case IS_NORM:
 392         switch (ch) {
 393         case 1:
 394             readline_bol(rs);
 395             break;
 396         case 4:
 397             readline_delete_char(rs);
 398             break;
 399         case 5:
 400             readline_eol(rs);
 401             break;
 402         case 9:
 403             readline_completion(rs);
 404             break;
 405         case 12:
 406             readline_clear_screen(rs);
 407             break;
 408         case 10:
 409         case 13:
 410             rs->cmd_buf[rs->cmd_buf_size] = '\0';
 411             if (!rs->read_password) {
 412                 readline_hist_add(rs, rs->cmd_buf);
 413             }
 414             rs->printf_func(rs->opaque, "\n");
 415             rs->cmd_buf_index = 0;
 416             rs->cmd_buf_size = 0;
 417             rs->last_cmd_buf_index = 0;
 418             rs->last_cmd_buf_size = 0;
 419             rs->readline_func(rs->opaque, rs->cmd_buf, rs->readline_opaque);
 420             break;
 421         case 23:
 422             /* ^W */
 423             readline_backword(rs);
 424             break;
 425         case 27:
 426             rs->esc_state = IS_ESC;
 427             break;
 428         case 127:
 429         case 8:
 430             readline_backspace(rs);
 431             break;
 432         case 155:
 433             rs->esc_state = IS_CSI;
 434             break;
 435         default:
 436             if (ch >= 32) {
 437                 readline_insert_char(rs, ch);
 438             }
 439             break;
 440         }
 441         break;
 442     case IS_ESC:
 443         if (ch == '[') {
 444             rs->esc_state = IS_CSI;
 445             rs->esc_param = 0;
 446         } else if (ch == 'O') {
 447             rs->esc_state = IS_SS3;
 448             rs->esc_param = 0;
 449         } else {
 450             rs->esc_state = IS_NORM;
 451         }
 452         break;
 453     case IS_CSI:
 454         switch (ch) {
 455         case 'A':
 456         case 'F':
 457             readline_up_char(rs);
 458             break;
 459         case 'B':
 460         case 'E':
 461             readline_down_char(rs);
 462             break;
 463         case 'D':
 464             readline_backward_char(rs);
 465             break;
 466         case 'C':
 467             readline_forward_char(rs);
 468             break;
 469         case '0' ... '9':
 470             rs->esc_param = rs->esc_param * 10 + (ch - '0');
 471             goto the_end;
 472         case '~':
 473             switch (rs->esc_param) {
 474             case 1:
 475                 readline_bol(rs);
 476                 break;
 477             case 3:
 478                 readline_delete_char(rs);
 479                 break;
 480             case 4:
 481                 readline_eol(rs);
 482                 break;
 483             }
 484             break;
 485         default:
 486             break;
 487         }
 488         rs->esc_state = IS_NORM;
 489     the_end:
 490         break;
 491     case IS_SS3:
 492         switch (ch) {
 493         case 'F':
 494             readline_eol(rs);
 495             break;
 496         case 'H':
 497             readline_bol(rs);
 498             break;
 499         }
 500         rs->esc_state = IS_NORM;
 501         break;
 502     }
 503     readline_update(rs);
 504 }
 505
 506 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
 507                     ReadLineFunc *readline_func, void *opaque)
 508 {
 509     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
 510     rs->readline_func = readline_func;
 511     rs->readline_opaque = opaque;
 512     rs->read_password = read_password;
 513     readline_restart(rs);
 514 }
 515
 516 void readline_restart(ReadLineState *rs)
 517 {
 518     rs->cmd_buf_index = 0;
 519     rs->cmd_buf_size = 0;
 520 }
 521
 522 const char *readline_get_history(ReadLineState *rs, unsigned int index)
 523 {
 524     if (index >= READLINE_MAX_CMDS) {
 525         return NULL;
 526     }
 527     return rs->history[index];
 528 }
 529
 530 void readline_free(ReadLineState *rs)
 531 {
 532     int i;
 533
 534     if (!rs) {
 535         return;
 536     }
 537     for (i = 0; i < READLINE_MAX_CMDS; i++) {
 538         g_free(rs->history[i]);
 539     }
 540     g_free(rs);
 541 }
 542
 543 ReadLineState *readline_init(ReadLinePrintfFunc *printf_func,
 544                              ReadLineFlushFunc *flush_func,
 545                              void *opaque,
 546                              ReadLineCompletionFunc *completion_finder)
 547 {
 548     ReadLineState *rs = g_new0(ReadLineState, 1);
 549
 550     rs->hist_entry = -1;
 551     rs->opaque = opaque;
 552     rs->printf_func = printf_func;
 553     rs->flush_func = flush_func;
 554     rs->completion_finder = completion_finder;
 555
 556     return rs;
 557 }