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         } else {
  60             rs->printf_func(rs->opaque, "%s", rs->cmd_buf);
  61         }
  62         rs->printf_func(rs->opaque, "\033[K");
  63         memcpy(rs->last_cmd_buf, rs->cmd_buf, rs->cmd_buf_size);
  64         rs->last_cmd_buf_size = rs->cmd_buf_size;
  65         rs->last_cmd_buf_index = rs->cmd_buf_size;
  66     }
  67     if (rs->cmd_buf_index != rs->last_cmd_buf_index) {
  68         delta = rs->cmd_buf_index - rs->last_cmd_buf_index;
  69         if (delta > 0) {
  70             for(i = 0;i < delta; i++) {
  71                 rs->printf_func(rs->opaque, "\033[C");
  72             }
  73         } else {
  74             delta = -delta;
  75             for(i = 0;i < delta; i++) {
  76                 rs->printf_func(rs->opaque, "\033[D");
  77             }
  78         }
  79         rs->last_cmd_buf_index = rs->cmd_buf_index;
  80     }
  81     rs->flush_func(rs->opaque);
  82 }
  83
  84 static void readline_insert_char(ReadLineState *rs, int ch)
  85 {
  86     if (rs->cmd_buf_index < READLINE_CMD_BUF_SIZE) {
  87         memmove(rs->cmd_buf + rs->cmd_buf_index + 1,
  88                 rs->cmd_buf + rs->cmd_buf_index,
  89                 rs->cmd_buf_size - rs->cmd_buf_index);
  90         rs->cmd_buf[rs->cmd_buf_index] = ch;
  91         rs->cmd_buf_size++;
  92         rs->cmd_buf_index++;
  93     }
  94 }
  95
  96 static void readline_backward_char(ReadLineState *rs)
  97 {
  98     if (rs->cmd_buf_index > 0) {
  99         rs->cmd_buf_index--;
 100     }
 101 }
 102
 103 static void readline_forward_char(ReadLineState *rs)
 104 {
 105     if (rs->cmd_buf_index < rs->cmd_buf_size) {
 106         rs->cmd_buf_index++;
 107     }
 108 }
 109
 110 static void readline_delete_char(ReadLineState *rs)
 111 {
 112     if (rs->cmd_buf_index < rs->cmd_buf_size) {
 113         memmove(rs->cmd_buf + rs->cmd_buf_index,
 114                 rs->cmd_buf + rs->cmd_buf_index + 1,
 115                 rs->cmd_buf_size - rs->cmd_buf_index - 1);
 116         rs->cmd_buf_size--;
 117     }
 118 }
 119
 120 static void readline_backspace(ReadLineState *rs)
 121 {
 122     if (rs->cmd_buf_index > 0) {
 123         readline_backward_char(rs);
 124         readline_delete_char(rs);
 125     }
 126 }
 127
 128 static void readline_backword(ReadLineState *rs)
 129 {
 130     int start;
 131
 132     if (rs->cmd_buf_index == 0 || rs->cmd_buf_index > rs->cmd_buf_size) {
 133         return;
 134     }
 135
 136     start = rs->cmd_buf_index - 1;
 137
 138     /* find first word (backwards) */
 139     while (start > 0) {
 140         if (!qemu_isspace(rs->cmd_buf[start])) {
 141             break;
 142         }
 143
 144         --start;
 145     }
 146
 147     /* find first space (backwards) */
 148     while (start > 0) {
 149         if (qemu_isspace(rs->cmd_buf[start])) {
 150             ++start;
 151             break;
 152         }
 153
 154         --start;
 155     }
 156
 157     /* remove word */
 158     if (start < rs->cmd_buf_index) {
 159         memmove(rs->cmd_buf + start,
 160                 rs->cmd_buf + rs->cmd_buf_index,
 161                 rs->cmd_buf_size - rs->cmd_buf_index);
 162         rs->cmd_buf_size -= rs->cmd_buf_index - start;
 163         rs->cmd_buf_index = start;
 164     }
 165 }
 166
 167 static void readline_bol(ReadLineState *rs)
 168 {
 169     rs->cmd_buf_index = 0;
 170 }
 171
 172 static void readline_eol(ReadLineState *rs)
 173 {
 174     rs->cmd_buf_index = rs->cmd_buf_size;
 175 }
 176
 177 static void readline_up_char(ReadLineState *rs)
 178 {
 179     int idx;
 180
 181     if (rs->hist_entry == 0)
 182         return;
 183     if (rs->hist_entry == -1) {
 184         /* Find latest entry */
 185         for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
 186             if (rs->history[idx] == NULL)
 187                 break;
 188         }
 189         rs->hist_entry = idx;
 190     }
 191     rs->hist_entry--;
 192     if (rs->hist_entry >= 0) {
 193         pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
 194                 rs->history[rs->hist_entry]);
 195         rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
 196     }
 197 }
 198
 199 static void readline_down_char(ReadLineState *rs)
 200 {
 201     if (rs->hist_entry == -1)
 202         return;
 203     if (rs->hist_entry < READLINE_MAX_CMDS - 1 &&
 204         rs->history[++rs->hist_entry] != NULL) {
 205         pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
 206                 rs->history[rs->hist_entry]);
 207     } else {
 208         rs->cmd_buf[0] = 0;
 209         rs->hist_entry = -1;
 210     }
 211     rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
 212 }
 213
 214 static void readline_hist_add(ReadLineState *rs, const char *cmdline)
 215 {
 216     char *hist_entry, *new_entry;
 217     int idx;
 218
 219     if (cmdline[0] == '\0')
 220         return;
 221     new_entry = NULL;
 222     if (rs->hist_entry != -1) {
 223         /* We were editing an existing history entry: replace it */
 224         hist_entry = rs->history[rs->hist_entry];
 225         idx = rs->hist_entry;
 226         if (strcmp(hist_entry, cmdline) == 0) {
 227             goto same_entry;
 228         }
 229     }
 230     /* Search cmdline in history buffers */
 231     for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
 232         hist_entry = rs->history[idx];
 233         if (hist_entry == NULL)
 234             break;
 235         if (strcmp(hist_entry, cmdline) == 0) {
 236         same_entry:
 237             new_entry = hist_entry;
 238             /* Put this entry at the end of history */
 239             memmove(&rs->history[idx], &rs->history[idx + 1],
 240                     (READLINE_MAX_CMDS - (idx + 1)) * sizeof(char *));
 241             rs->history[READLINE_MAX_CMDS - 1] = NULL;
 242             for (; idx < READLINE_MAX_CMDS; idx++) {
 243                 if (rs->history[idx] == NULL)
 244                     break;
 245             }
 246             break;
 247         }
 248     }
 249     if (idx == READLINE_MAX_CMDS) {
 250         /* Need to get one free slot */
 251         g_free(rs->history[0]);
 252         memmove(rs->history, &rs->history[1],
 253                 (READLINE_MAX_CMDS - 1) * sizeof(char *));
 254         rs->history[READLINE_MAX_CMDS - 1] = NULL;
 255         idx = READLINE_MAX_CMDS - 1;
 256     }
 257     if (new_entry == NULL)
 258         new_entry = g_strdup(cmdline);
 259     rs->history[idx] = new_entry;
 260     rs->hist_entry = -1;
 261 }
 262
 263 /* completion support */
 264
 265 void readline_add_completion(ReadLineState *rs, const char *str)
 266 {
 267     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
 268         int i;
 269         for (i = 0; i < rs->nb_completions; i++) {
 270             if (!strcmp(rs->completions[i], str)) {
 271                 return;
 272             }
 273         }
 274         rs->completions[rs->nb_completions++] = g_strdup(str);
 275     }
 276 }
 277
 278 void readline_set_completion_index(ReadLineState *rs, int index)
 279 {
 280     rs->completion_index = index;
 281 }
 282
 283 static int completion_comp(const void *a, const void *b)
 284 {
 285     return strcmp(*(const char **) a, *(const char **) b);
 286 }
 287
 288 static void readline_completion(ReadLineState *rs)
 289 {
 290     int len, i, j, max_width, nb_cols, max_prefix;
 291     char *cmdline;
 292
 293     rs->nb_completions = 0;
 294
 295     cmdline = g_strndup(rs->cmd_buf, rs->cmd_buf_index);
 296     rs->completion_finder(rs->opaque, cmdline);
 297     g_free(cmdline);
 298
 299     /* no completion found */
 300     if (rs->nb_completions <= 0)
 301         return;
 302     if (rs->nb_completions == 1) {
 303         len = strlen(rs->completions[0]);
 304         for(i = rs->completion_index; i < len; i++) {
 305             readline_insert_char(rs, rs->completions[0][i]);
 306         }
 307         /* extra space for next argument. XXX: make it more generic */
 308         if (len > 0 && rs->completions[0][len - 1] != '/')
 309             readline_insert_char(rs, ' ');
 310     } else {
 311         qsort(rs->completions, rs->nb_completions, sizeof(char *),
 312               completion_comp);
 313         rs->printf_func(rs->opaque, "\n");
 314         max_width = 0;
 315         max_prefix = 0;
 316         for(i = 0; i < rs->nb_completions; i++) {
 317             len = strlen(rs->completions[i]);
 318             if (i==0) {
 319                 max_prefix = len;
 320             } else {
 321                 if (len < max_prefix)
 322                     max_prefix = len;
 323                 for(j=0; j<max_prefix; j++) {
 324                     if (rs->completions[i][j] != rs->completions[0][j])
 325                         max_prefix = j;
 326                 }
 327             }
 328             if (len > max_width)
 329                 max_width = len;
 330         }
 331         if (max_prefix > 0)
 332             for(i = rs->completion_index; i < max_prefix; i++) {
 333                 readline_insert_char(rs, rs->completions[0][i]);
 334             }
 335         max_width += 2;
 336         if (max_width < 10)
 337             max_width = 10;
 338         else if (max_width > 80)
 339             max_width = 80;
 340         nb_cols = 80 / max_width;
 341         j = 0;
 342         for(i = 0; i < rs->nb_completions; i++) {
 343             rs->printf_func(rs->opaque, "%-*s", max_width, rs->completions[i]);
 344             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
 345                 rs->printf_func(rs->opaque, "\n");
 346                 j = 0;
 347             }
 348         }
 349         readline_show_prompt(rs);
 350     }
 351     for (i = 0; i < rs->nb_completions; i++) {
 352         g_free(rs->completions[i]);
 353     }
 354 }
 355
 356 static void readline_clear_screen(ReadLineState *rs)
 357 {
 358     rs->printf_func(rs->opaque, "\033[2J\033[1;1H");
 359     readline_show_prompt(rs);
 360 }
 361
 362 /* return true if command handled */
 363 void readline_handle_byte(ReadLineState *rs, int ch)
 364 {
 365     switch(rs->esc_state) {
 366     case IS_NORM:
 367         switch(ch) {
 368         case 1:
 369             readline_bol(rs);
 370             break;
 371         case 4:
 372             readline_delete_char(rs);
 373             break;
 374         case 5:
 375             readline_eol(rs);
 376             break;
 377         case 9:
 378             readline_completion(rs);
 379             break;
 380         case 12:
 381             readline_clear_screen(rs);
 382             break;
 383         case 10:
 384         case 13:
 385             rs->cmd_buf[rs->cmd_buf_size] = '\0';
 386             if (!rs->read_password)
 387                 readline_hist_add(rs, rs->cmd_buf);
 388             rs->printf_func(rs->opaque, "\n");
 389             rs->cmd_buf_index = 0;
 390             rs->cmd_buf_size = 0;
 391             rs->last_cmd_buf_index = 0;
 392             rs->last_cmd_buf_size = 0;
 393             rs->readline_func(rs->opaque, rs->cmd_buf, rs->readline_opaque);
 394             break;
 395         case 23:
 396             /* ^W */
 397             readline_backword(rs);
 398             break;
 399         case 27:
 400             rs->esc_state = IS_ESC;
 401             break;
 402         case 127:
 403         case 8:
 404             readline_backspace(rs);
 405             break;
 406         case 155:
 407             rs->esc_state = IS_CSI;
 408             break;
 409         default:
 410             if (ch >= 32) {
 411                 readline_insert_char(rs, ch);
 412             }
 413             break;
 414         }
 415         break;
 416     case IS_ESC:
 417         if (ch == '[') {
 418             rs->esc_state = IS_CSI;
 419             rs->esc_param = 0;
 420         } else if (ch == 'O') {
 421             rs->esc_state = IS_SS3;
 422             rs->esc_param = 0;
 423         } else {
 424             rs->esc_state = IS_NORM;
 425         }
 426         break;
 427     case IS_CSI:
 428         switch(ch) {
 429         case 'A':
 430         case 'F':
 431             readline_up_char(rs);
 432             break;
 433         case 'B':
 434         case 'E':
 435             readline_down_char(rs);
 436             break;
 437         case 'D':
 438             readline_backward_char(rs);
 439             break;
 440         case 'C':
 441             readline_forward_char(rs);
 442             break;
 443         case '0' ... '9':
 444             rs->esc_param = rs->esc_param * 10 + (ch - '0');
 445             goto the_end;
 446         case '~':
 447             switch(rs->esc_param) {
 448             case 1:
 449                 readline_bol(rs);
 450                 break;
 451             case 3:
 452                 readline_delete_char(rs);
 453                 break;
 454             case 4:
 455                 readline_eol(rs);
 456                 break;
 457             }
 458             break;
 459         default:
 460             break;
 461         }
 462         rs->esc_state = IS_NORM;
 463     the_end:
 464         break;
 465     case IS_SS3:
 466         switch(ch) {
 467         case 'F':
 468             readline_eol(rs);
 469             break;
 470         case 'H':
 471             readline_bol(rs);
 472             break;
 473         }
 474         rs->esc_state = IS_NORM;
 475         break;
 476     }
 477     readline_update(rs);
 478 }
 479
 480 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
 481                     ReadLineFunc *readline_func, void *opaque)
 482 {
 483     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
 484     rs->readline_func = readline_func;
 485     rs->readline_opaque = opaque;
 486     rs->read_password = read_password;
 487     readline_restart(rs);
 488 }
 489
 490 void readline_restart(ReadLineState *rs)
 491 {
 492     rs->cmd_buf_index = 0;
 493     rs->cmd_buf_size = 0;
 494 }
 495
 496 const char *readline_get_history(ReadLineState *rs, unsigned int index)
 497 {
 498     if (index >= READLINE_MAX_CMDS)
 499         return NULL;
 500     return rs->history[index];
 501 }
 502
 503 ReadLineState *readline_init(ReadLinePrintfFunc *printf_func,
 504                              ReadLineFlushFunc *flush_func,
 505                              void *opaque,
 506                              ReadLineCompletionFunc *completion_finder)
 507 {
 508     ReadLineState *rs = g_malloc0(sizeof(*rs));
 509
 510     rs->hist_entry = -1;
 511     rs->opaque = opaque;
 512     rs->printf_func = printf_func;
 513     rs->flush_func = flush_func;
 514     rs->completion_finder = completion_finder;
 515
 516     return rs;
 517 }