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