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-common.h"
  27 #include "qemu/readline.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             new_entry = hist_entry;
 244             /* Put this entry at the end of history */
 245             memmove(&rs->history[idx], &rs->history[idx + 1],
 246                     (READLINE_MAX_CMDS - (idx + 1)) * sizeof(char *));
 247             rs->history[READLINE_MAX_CMDS - 1] = NULL;
 248             for (; idx < READLINE_MAX_CMDS; idx++) {
 249                 if (rs->history[idx] == NULL) {
 250                     break;
 251                 }
 252             }
 253             break;
 254         }
 255     }
 256     if (idx == READLINE_MAX_CMDS) {
 257         /* Need to get one free slot */
 258         g_free(rs->history[0]);
 259         memmove(rs->history, &rs->history[1],
 260                 (READLINE_MAX_CMDS - 1) * sizeof(char *));
 261         rs->history[READLINE_MAX_CMDS - 1] = NULL;
 262         idx = READLINE_MAX_CMDS - 1;
 263     }
 264     if (new_entry == NULL) {
 265         new_entry = g_strdup(cmdline);
 266     }
 267     rs->history[idx] = new_entry;
 268     rs->hist_entry = -1;
 269 }
 270
 271 /* completion support */
 272
 273 void readline_add_completion(ReadLineState *rs, const char *str)
 274 {
 275     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
 276         int i;
 277         for (i = 0; i < rs->nb_completions; i++) {
 278             if (!strcmp(rs->completions[i], str)) {
 279                 return;
 280             }
 281         }
 282         rs->completions[rs->nb_completions++] = g_strdup(str);
 283     }
 284 }
 285
 286 void readline_set_completion_index(ReadLineState *rs, int index)
 287 {
 288     rs->completion_index = index;
 289 }
 290
 291 static int completion_comp(const void *a, const void *b)
 292 {
 293     return strcmp(*(const char **) a, *(const char **) b);
 294 }
 295
 296 static void readline_completion(ReadLineState *rs)
 297 {
 298     int len, i, j, max_width, nb_cols, max_prefix;
 299     char *cmdline;
 300
 301     rs->nb_completions = 0;
 302
 303     cmdline = g_strndup(rs->cmd_buf, rs->cmd_buf_index);
 304     rs->completion_finder(rs->opaque, cmdline);
 305     g_free(cmdline);
 306
 307     /* no completion found */
 308     if (rs->nb_completions <= 0) {
 309         return;
 310     }
 311     if (rs->nb_completions == 1) {
 312         len = strlen(rs->completions[0]);
 313         for (i = rs->completion_index; i < len; i++) {
 314             readline_insert_char(rs, rs->completions[0][i]);
 315         }
 316         /* extra space for next argument. XXX: make it more generic */
 317         if (len > 0 && rs->completions[0][len - 1] != '/') {
 318             readline_insert_char(rs, ' ');
 319         }
 320     } else {
 321         qsort(rs->completions, rs->nb_completions, sizeof(char *),
 322               completion_comp);
 323         rs->printf_func(rs->opaque, "\n");
 324         max_width = 0;
 325         max_prefix = 0;
 326         for (i = 0; i < rs->nb_completions; i++) {
 327             len = strlen(rs->completions[i]);
 328             if (i == 0) {
 329                 max_prefix = len;
 330             } else {
 331                 if (len < max_prefix) {
 332                     max_prefix = len;
 333                 }
 334                 for (j = 0; j < max_prefix; j++) {
 335                     if (rs->completions[i][j] != rs->completions[0][j]) {
 336                         max_prefix = j;
 337                     }
 338                 }
 339             }
 340             if (len > max_width) {
 341                 max_width = len;
 342             }
 343         }
 344         if (max_prefix > 0)
 345             for (i = rs->completion_index; i < max_prefix; i++) {
 346                 readline_insert_char(rs, rs->completions[0][i]);
 347             }
 348         max_width += 2;
 349         if (max_width < 10) {
 350             max_width = 10;
 351         } else if (max_width > 80) {
 352             max_width = 80;
 353         }
 354         nb_cols = 80 / max_width;
 355         j = 0;
 356         for (i = 0; i < rs->nb_completions; i++) {
 357             rs->printf_func(rs->opaque, "%-*s", max_width, rs->completions[i]);
 358             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
 359                 rs->printf_func(rs->opaque, "\n");
 360                 j = 0;
 361             }
 362         }
 363         readline_show_prompt(rs);
 364     }
 365     for (i = 0; i < rs->nb_completions; i++) {
 366         g_free(rs->completions[i]);
 367     }
 368 }
 369
 370 static void readline_clear_screen(ReadLineState *rs)
 371 {
 372     rs->printf_func(rs->opaque, "\033[2J\033[1;1H");
 373     readline_show_prompt(rs);
 374 }
 375
 376 /* return true if command handled */
 377 void readline_handle_byte(ReadLineState *rs, int ch)
 378 {
 379     switch (rs->esc_state) {
 380     case IS_NORM:
 381         switch (ch) {
 382         case 1:
 383             readline_bol(rs);
 384             break;
 385         case 4:
 386             readline_delete_char(rs);
 387             break;
 388         case 5:
 389             readline_eol(rs);
 390             break;
 391         case 9:
 392             readline_completion(rs);
 393             break;
 394         case 12:
 395             readline_clear_screen(rs);
 396             break;
 397         case 10:
 398         case 13:
 399             rs->cmd_buf[rs->cmd_buf_size] = '\0';
 400             if (!rs->read_password) {
 401                 readline_hist_add(rs, rs->cmd_buf);
 402             }
 403             rs->printf_func(rs->opaque, "\n");
 404             rs->cmd_buf_index = 0;
 405             rs->cmd_buf_size = 0;
 406             rs->last_cmd_buf_index = 0;
 407             rs->last_cmd_buf_size = 0;
 408             rs->readline_func(rs->opaque, rs->cmd_buf, rs->readline_opaque);
 409             break;
 410         case 23:
 411             /* ^W */
 412             readline_backword(rs);
 413             break;
 414         case 27:
 415             rs->esc_state = IS_ESC;
 416             break;
 417         case 127:
 418         case 8:
 419             readline_backspace(rs);
 420             break;
 421         case 155:
 422             rs->esc_state = IS_CSI;
 423             break;
 424         default:
 425             if (ch >= 32) {
 426                 readline_insert_char(rs, ch);
 427             }
 428             break;
 429         }
 430         break;
 431     case IS_ESC:
 432         if (ch == '[') {
 433             rs->esc_state = IS_CSI;
 434             rs->esc_param = 0;
 435         } else if (ch == 'O') {
 436             rs->esc_state = IS_SS3;
 437             rs->esc_param = 0;
 438         } else {
 439             rs->esc_state = IS_NORM;
 440         }
 441         break;
 442     case IS_CSI:
 443         switch (ch) {
 444         case 'A':
 445         case 'F':
 446             readline_up_char(rs);
 447             break;
 448         case 'B':
 449         case 'E':
 450             readline_down_char(rs);
 451             break;
 452         case 'D':
 453             readline_backward_char(rs);
 454             break;
 455         case 'C':
 456             readline_forward_char(rs);
 457             break;
 458         case '0' ... '9':
 459             rs->esc_param = rs->esc_param * 10 + (ch - '0');
 460             goto the_end;
 461         case '~':
 462             switch (rs->esc_param) {
 463             case 1:
 464                 readline_bol(rs);
 465                 break;
 466             case 3:
 467                 readline_delete_char(rs);
 468                 break;
 469             case 4:
 470                 readline_eol(rs);
 471                 break;
 472             }
 473             break;
 474         default:
 475             break;
 476         }
 477         rs->esc_state = IS_NORM;
 478     the_end:
 479         break;
 480     case IS_SS3:
 481         switch (ch) {
 482         case 'F':
 483             readline_eol(rs);
 484             break;
 485         case 'H':
 486             readline_bol(rs);
 487             break;
 488         }
 489         rs->esc_state = IS_NORM;
 490         break;
 491     }
 492     readline_update(rs);
 493 }
 494
 495 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
 496                     ReadLineFunc *readline_func, void *opaque)
 497 {
 498     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
 499     rs->readline_func = readline_func;
 500     rs->readline_opaque = opaque;
 501     rs->read_password = read_password;
 502     readline_restart(rs);
 503 }
 504
 505 void readline_restart(ReadLineState *rs)
 506 {
 507     rs->cmd_buf_index = 0;
 508     rs->cmd_buf_size = 0;
 509 }
 510
 511 const char *readline_get_history(ReadLineState *rs, unsigned int index)
 512 {
 513     if (index >= READLINE_MAX_CMDS) {
 514         return NULL;
 515     }
 516     return rs->history[index];
 517 }
 518
 519 void readline_free(ReadLineState *rs)
 520 {
 521     int i;
 522
 523     if (!rs) {
 524         return;
 525     }
 526     for (i = 0; i < READLINE_MAX_CMDS; i++) {
 527         g_free(rs->history[i]);
 528     }
 529     g_free(rs);
 530 }
 531
 532 ReadLineState *readline_init(ReadLinePrintfFunc *printf_func,
 533                              ReadLineFlushFunc *flush_func,
 534                              void *opaque,
 535                              ReadLineCompletionFunc *completion_finder)
 536 {
 537     ReadLineState *rs = g_new0(ReadLineState, 1);
 538
 539     rs->hist_entry = -1;
 540     rs->opaque = opaque;
 541     rs->printf_func = printf_func;
 542     rs->flush_func = flush_func;
 543     rs->completion_finder = completion_finder;
 544
 545     return rs;
 546 }