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
  29 #define IS_NORM 0
  30 #define IS_ESC  1
  31 #define IS_CSI  2
  32 #define IS_SS3  3
  33
  34 void readline_show_prompt(ReadLineState *rs)
  35 {
  36     rs->printf_func(rs->opaque, "%s", rs->prompt);
  37     rs->flush_func(rs->opaque);
  38     rs->last_cmd_buf_index = 0;
  39     rs->last_cmd_buf_size = 0;
  40     rs->esc_state = IS_NORM;
  41 }
  42
  43 /* update the displayed command line */
  44 static void readline_update(ReadLineState *rs)
  45 {
  46     int i, delta, len;
  47
  48     if (rs->cmd_buf_size != rs->last_cmd_buf_size ||
  49         memcmp(rs->cmd_buf, rs->last_cmd_buf, rs->cmd_buf_size) != 0) {
  50         for(i = 0; i < rs->last_cmd_buf_index; i++) {
  51             rs->printf_func(rs->opaque, "\033[D");
  52         }
  53         rs->cmd_buf[rs->cmd_buf_size] = '\0';
  54         if (rs->read_password) {
  55             len = strlen(rs->cmd_buf);
  56             for(i = 0; i < len; i++)
  57                 rs->printf_func(rs->opaque, "*");
  58         } else {
  59             rs->printf_func(rs->opaque, "%s", rs->cmd_buf);
  60         }
  61         rs->printf_func(rs->opaque, "\033[K");
  62         memcpy(rs->last_cmd_buf, rs->cmd_buf, rs->cmd_buf_size);
  63         rs->last_cmd_buf_size = rs->cmd_buf_size;
  64         rs->last_cmd_buf_index = rs->cmd_buf_size;
  65     }
  66     if (rs->cmd_buf_index != rs->last_cmd_buf_index) {
  67         delta = rs->cmd_buf_index - rs->last_cmd_buf_index;
  68         if (delta > 0) {
  69             for(i = 0;i < delta; i++) {
  70                 rs->printf_func(rs->opaque, "\033[C");
  71             }
  72         } else {
  73             delta = -delta;
  74             for(i = 0;i < delta; i++) {
  75                 rs->printf_func(rs->opaque, "\033[D");
  76             }
  77         }
  78         rs->last_cmd_buf_index = rs->cmd_buf_index;
  79     }
  80     rs->flush_func(rs->opaque);
  81 }
  82
  83 static void readline_insert_char(ReadLineState *rs, int ch)
  84 {
  85     if (rs->cmd_buf_index < READLINE_CMD_BUF_SIZE) {
  86         memmove(rs->cmd_buf + rs->cmd_buf_index + 1,
  87                 rs->cmd_buf + rs->cmd_buf_index,
  88                 rs->cmd_buf_size - rs->cmd_buf_index);
  89         rs->cmd_buf[rs->cmd_buf_index] = ch;
  90         rs->cmd_buf_size++;
  91         rs->cmd_buf_index++;
  92     }
  93 }
  94
  95 static void readline_backward_char(ReadLineState *rs)
  96 {
  97     if (rs->cmd_buf_index > 0) {
  98         rs->cmd_buf_index--;
  99     }
 100 }
 101
 102 static void readline_forward_char(ReadLineState *rs)
 103 {
 104     if (rs->cmd_buf_index < rs->cmd_buf_size) {
 105         rs->cmd_buf_index++;
 106     }
 107 }
 108
 109 static void readline_delete_char(ReadLineState *rs)
 110 {
 111     if (rs->cmd_buf_index < rs->cmd_buf_size) {
 112         memmove(rs->cmd_buf + rs->cmd_buf_index,
 113                 rs->cmd_buf + rs->cmd_buf_index + 1,
 114                 rs->cmd_buf_size - rs->cmd_buf_index - 1);
 115         rs->cmd_buf_size--;
 116     }
 117 }
 118
 119 static void readline_backspace(ReadLineState *rs)
 120 {
 121     if (rs->cmd_buf_index > 0) {
 122         readline_backward_char(rs);
 123         readline_delete_char(rs);
 124     }
 125 }
 126
 127 static void readline_backword(ReadLineState *rs)
 128 {
 129     int start;
 130
 131     if (rs->cmd_buf_index == 0 || rs->cmd_buf_index > rs->cmd_buf_size) {
 132         return;
 133     }
 134
 135     start = rs->cmd_buf_index - 1;
 136
 137     /* find first word (backwards) */
 138     while (start > 0) {
 139         if (!qemu_isspace(rs->cmd_buf[start])) {
 140             break;
 141         }
 142
 143         --start;
 144     }
 145
 146     /* find first space (backwards) */
 147     while (start > 0) {
 148         if (qemu_isspace(rs->cmd_buf[start])) {
 149             ++start;
 150             break;
 151         }
 152
 153         --start;
 154     }
 155
 156     /* remove word */
 157     if (start < rs->cmd_buf_index) {
 158         memmove(rs->cmd_buf + start,
 159                 rs->cmd_buf + rs->cmd_buf_index,
 160                 rs->cmd_buf_size - rs->cmd_buf_index);
 161         rs->cmd_buf_size -= rs->cmd_buf_index - start;
 162         rs->cmd_buf_index = start;
 163     }
 164 }
 165
 166 static void readline_bol(ReadLineState *rs)
 167 {
 168     rs->cmd_buf_index = 0;
 169 }
 170
 171 static void readline_eol(ReadLineState *rs)
 172 {
 173     rs->cmd_buf_index = rs->cmd_buf_size;
 174 }
 175
 176 static void readline_up_char(ReadLineState *rs)
 177 {
 178     int idx;
 179
 180     if (rs->hist_entry == 0)
 181         return;
 182     if (rs->hist_entry == -1) {
 183         /* Find latest entry */
 184         for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
 185             if (rs->history[idx] == NULL)
 186                 break;
 187         }
 188         rs->hist_entry = idx;
 189     }
 190     rs->hist_entry--;
 191     if (rs->hist_entry >= 0) {
 192         pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
 193                 rs->history[rs->hist_entry]);
 194         rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
 195     }
 196 }
 197
 198 static void readline_down_char(ReadLineState *rs)
 199 {
 200     if (rs->hist_entry == -1)
 201         return;
 202     if (rs->hist_entry < READLINE_MAX_CMDS - 1 &&
 203         rs->history[++rs->hist_entry] != NULL) {
 204         pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
 205                 rs->history[rs->hist_entry]);
 206     } else {
 207         rs->cmd_buf[0] = 0;
 208         rs->hist_entry = -1;
 209     }
 210     rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
 211 }
 212
 213 static void readline_hist_add(ReadLineState *rs, const char *cmdline)
 214 {
 215     char *hist_entry, *new_entry;
 216     int idx;
 217
 218     if (cmdline[0] == '\0')
 219         return;
 220     new_entry = NULL;
 221     if (rs->hist_entry != -1) {
 222         /* We were editing an existing history entry: replace it */
 223         hist_entry = rs->history[rs->hist_entry];
 224         idx = rs->hist_entry;
 225         if (strcmp(hist_entry, cmdline) == 0) {
 226             goto same_entry;
 227         }
 228     }
 229     /* Search cmdline in history buffers */
 230     for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
 231         hist_entry = rs->history[idx];
 232         if (hist_entry == NULL)
 233             break;
 234         if (strcmp(hist_entry, cmdline) == 0) {
 235         same_entry:
 236             new_entry = hist_entry;
 237             /* Put this entry at the end of history */
 238             memmove(&rs->history[idx], &rs->history[idx + 1],
 239                     (READLINE_MAX_CMDS - (idx + 1)) * sizeof(char *));
 240             rs->history[READLINE_MAX_CMDS - 1] = NULL;
 241             for (; idx < READLINE_MAX_CMDS; idx++) {
 242                 if (rs->history[idx] == NULL)
 243                     break;
 244             }
 245             break;
 246         }
 247     }
 248     if (idx == READLINE_MAX_CMDS) {
 249         /* Need to get one free slot */
 250         g_free(rs->history[0]);
 251         memmove(rs->history, &rs->history[1],
 252                 (READLINE_MAX_CMDS - 1) * sizeof(char *));
 253         rs->history[READLINE_MAX_CMDS - 1] = NULL;
 254         idx = READLINE_MAX_CMDS - 1;
 255     }
 256     if (new_entry == NULL)
 257         new_entry = g_strdup(cmdline);
 258     rs->history[idx] = new_entry;
 259     rs->hist_entry = -1;
 260 }
 261
 262 /* completion support */
 263
 264 void readline_add_completion(ReadLineState *rs, const char *str)
 265 {
 266     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
 267         int i;
 268         for (i = 0; i < rs->nb_completions; i++) {
 269             if (!strcmp(rs->completions[i], str)) {
 270                 return;
 271             }
 272         }
 273         rs->completions[rs->nb_completions++] = g_strdup(str);
 274     }
 275 }
 276
 277 void readline_set_completion_index(ReadLineState *rs, int index)
 278 {
 279     rs->completion_index = index;
 280 }
 281
 282 static int completion_comp(const void *a, const void *b)
 283 {
 284     return strcmp(*(const char **) a, *(const char **) b);
 285 }
 286
 287 static void readline_completion(ReadLineState *rs)
 288 {
 289     int len, i, j, max_width, nb_cols, max_prefix;
 290     char *cmdline;
 291
 292     rs->nb_completions = 0;
 293
 294     cmdline = g_strndup(rs->cmd_buf, rs->cmd_buf_index);
 295     rs->completion_finder(rs->opaque, cmdline);
 296     g_free(cmdline);
 297
 298     /* no completion found */
 299     if (rs->nb_completions <= 0)
 300         return;
 301     if (rs->nb_completions == 1) {
 302         len = strlen(rs->completions[0]);
 303         for(i = rs->completion_index; i < len; i++) {
 304             readline_insert_char(rs, rs->completions[0][i]);
 305         }
 306         /* extra space for next argument. XXX: make it more generic */
 307         if (len > 0 && rs->completions[0][len - 1] != '/')
 308             readline_insert_char(rs, ' ');
 309     } else {
 310         qsort(rs->completions, rs->nb_completions, sizeof(char *),
 311               completion_comp);
 312         rs->printf_func(rs->opaque, "\n");
 313         max_width = 0;
 314         max_prefix = 0;
 315         for(i = 0; i < rs->nb_completions; i++) {
 316             len = strlen(rs->completions[i]);
 317             if (i==0) {
 318                 max_prefix = len;
 319             } else {
 320                 if (len < max_prefix)
 321                     max_prefix = len;
 322                 for(j=0; j<max_prefix; j++) {
 323                     if (rs->completions[i][j] != rs->completions[0][j])
 324                         max_prefix = j;
 325                 }
 326             }
 327             if (len > max_width)
 328                 max_width = len;
 329         }
 330         if (max_prefix > 0)
 331             for(i = rs->completion_index; i < max_prefix; i++) {
 332                 readline_insert_char(rs, rs->completions[0][i]);
 333             }
 334         max_width += 2;
 335         if (max_width < 10)
 336             max_width = 10;
 337         else if (max_width > 80)
 338             max_width = 80;
 339         nb_cols = 80 / max_width;
 340         j = 0;
 341         for(i = 0; i < rs->nb_completions; i++) {
 342             rs->printf_func(rs->opaque, "%-*s", max_width, rs->completions[i]);
 343             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
 344                 rs->printf_func(rs->opaque, "\n");
 345                 j = 0;
 346             }
 347         }
 348         readline_show_prompt(rs);
 349     }
 350     for (i = 0; i < rs->nb_completions; i++) {
 351         g_free(rs->completions[i]);
 352     }
 353 }
 354
 355 static void readline_clear_screen(ReadLineState *rs)
 356 {
 357     rs->printf_func(rs->opaque, "\033[2J\033[1;1H");
 358     readline_show_prompt(rs);
 359 }
 360
 361 /* return true if command handled */
 362 void readline_handle_byte(ReadLineState *rs, int ch)
 363 {
 364     switch(rs->esc_state) {
 365     case IS_NORM:
 366         switch(ch) {
 367         case 1:
 368             readline_bol(rs);
 369             break;
 370         case 4:
 371             readline_delete_char(rs);
 372             break;
 373         case 5:
 374             readline_eol(rs);
 375             break;
 376         case 9:
 377             readline_completion(rs);
 378             break;
 379         case 12:
 380             readline_clear_screen(rs);
 381             break;
 382         case 10:
 383         case 13:
 384             rs->cmd_buf[rs->cmd_buf_size] = '\0';
 385             if (!rs->read_password)
 386                 readline_hist_add(rs, rs->cmd_buf);
 387             rs->printf_func(rs->opaque, "\n");
 388             rs->cmd_buf_index = 0;
 389             rs->cmd_buf_size = 0;
 390             rs->last_cmd_buf_index = 0;
 391             rs->last_cmd_buf_size = 0;
 392             rs->readline_func(rs->opaque, rs->cmd_buf, rs->readline_opaque);
 393             break;
 394         case 23:
 395             /* ^W */
 396             readline_backword(rs);
 397             break;
 398         case 27:
 399             rs->esc_state = IS_ESC;
 400             break;
 401         case 127:
 402         case 8:
 403             readline_backspace(rs);
 404             break;
 405         case 155:
 406             rs->esc_state = IS_CSI;
 407             break;
 408         default:
 409             if (ch >= 32) {
 410                 readline_insert_char(rs, ch);
 411             }
 412             break;
 413         }
 414         break;
 415     case IS_ESC:
 416         if (ch == '[') {
 417             rs->esc_state = IS_CSI;
 418             rs->esc_param = 0;
 419         } else if (ch == 'O') {
 420             rs->esc_state = IS_SS3;
 421             rs->esc_param = 0;
 422         } else {
 423             rs->esc_state = IS_NORM;
 424         }
 425         break;
 426     case IS_CSI:
 427         switch(ch) {
 428         case 'A':
 429         case 'F':
 430             readline_up_char(rs);
 431             break;
 432         case 'B':
 433         case 'E':
 434             readline_down_char(rs);
 435             break;
 436         case 'D':
 437             readline_backward_char(rs);
 438             break;
 439         case 'C':
 440             readline_forward_char(rs);
 441             break;
 442         case '0' ... '9':
 443             rs->esc_param = rs->esc_param * 10 + (ch - '0');
 444             goto the_end;
 445         case '~':
 446             switch(rs->esc_param) {
 447             case 1:
 448                 readline_bol(rs);
 449                 break;
 450             case 3:
 451                 readline_delete_char(rs);
 452                 break;
 453             case 4:
 454                 readline_eol(rs);
 455                 break;
 456             }
 457             break;
 458         default:
 459             break;
 460         }
 461         rs->esc_state = IS_NORM;
 462     the_end:
 463         break;
 464     case IS_SS3:
 465         switch(ch) {
 466         case 'F':
 467             readline_eol(rs);
 468             break;
 469         case 'H':
 470             readline_bol(rs);
 471             break;
 472         }
 473         rs->esc_state = IS_NORM;
 474         break;
 475     }
 476     readline_update(rs);
 477 }
 478
 479 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
 480                     ReadLineFunc *readline_func, void *opaque)
 481 {
 482     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
 483     rs->readline_func = readline_func;
 484     rs->readline_opaque = opaque;
 485     rs->read_password = read_password;
 486     readline_restart(rs);
 487 }
 488
 489 void readline_restart(ReadLineState *rs)
 490 {
 491     rs->cmd_buf_index = 0;
 492     rs->cmd_buf_size = 0;
 493 }
 494
 495 const char *readline_get_history(ReadLineState *rs, unsigned int index)
 496 {
 497     if (index >= READLINE_MAX_CMDS)
 498         return NULL;
 499     return rs->history[index];
 500 }
 501
 502 ReadLineState *readline_init(ReadLinePrintfFunc *printf_func,
 503                              ReadLineFlushFunc *flush_func,
 504                              void *opaque,
 505                              ReadLineCompletionFunc *completion_finder)
 506 {
 507     ReadLineState *rs = g_malloc0(sizeof(*rs));
 508
 509     rs->hist_entry = -1;
 510     rs->opaque = opaque;
 511     rs->printf_func = printf_func;
 512     rs->flush_func = flush_func;
 513     rs->completion_finder = completion_finder;
 514
 515     return rs;
 516 }