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 #include "monitor/readline.h"
  25 #include "monitor/monitor.h"
  26
  27 #define IS_NORM 0
  28 #define IS_ESC  1
  29 #define IS_CSI  2
  30
  31 #undef printf
  32 #define printf do_not_use_printf
  33
  34 void readline_show_prompt(ReadLineState *rs)
  35 {
  36     monitor_printf(rs->mon, "%s", rs->prompt);
  37     monitor_flush(rs->mon);
  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             monitor_printf(rs->mon, "\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                 monitor_printf(rs->mon, "*");
  58         } else {
  59             monitor_printf(rs->mon, "%s", rs->cmd_buf);
  60         }
  61         monitor_printf(rs->mon, "\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                 monitor_printf(rs->mon, "\033[C");
  71             }
  72         } else {
  73             delta = -delta;
  74             for(i = 0;i < delta; i++) {
  75                 monitor_printf(rs->mon, "\033[D");
  76             }
  77         }
  78         rs->last_cmd_buf_index = rs->cmd_buf_index;
  79     }
  80     monitor_flush(rs->mon);
  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         free(rs->history[0]);
 251         memcpy(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 = 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         rs->completions[rs->nb_completions++] = g_strdup(str);
 268     }
 269 }
 270
 271 void readline_set_completion_index(ReadLineState *rs, int index)
 272 {
 273     rs->completion_index = index;
 274 }
 275
 276 static void readline_completion(ReadLineState *rs)
 277 {
 278     Monitor *mon = cur_mon;
 279     int len, i, j, max_width, nb_cols, max_prefix;
 280     char *cmdline;
 281
 282     rs->nb_completions = 0;
 283
 284     cmdline = g_malloc(rs->cmd_buf_index + 1);
 285     memcpy(cmdline, rs->cmd_buf, rs->cmd_buf_index);
 286     cmdline[rs->cmd_buf_index] = '\0';
 287     rs->completion_finder(cmdline);
 288     g_free(cmdline);
 289
 290     /* no completion found */
 291     if (rs->nb_completions <= 0)
 292         return;
 293     if (rs->nb_completions == 1) {
 294         len = strlen(rs->completions[0]);
 295         for(i = rs->completion_index; i < len; i++) {
 296             readline_insert_char(rs, rs->completions[0][i]);
 297         }
 298         /* extra space for next argument. XXX: make it more generic */
 299         if (len > 0 && rs->completions[0][len - 1] != '/')
 300             readline_insert_char(rs, ' ');
 301     } else {
 302         monitor_printf(mon, "\n");
 303         max_width = 0;
 304         max_prefix = 0;
 305         for(i = 0; i < rs->nb_completions; i++) {
 306             len = strlen(rs->completions[i]);
 307             if (i==0) {
 308                 max_prefix = len;
 309             } else {
 310                 if (len < max_prefix)
 311                     max_prefix = len;
 312                 for(j=0; j<max_prefix; j++) {
 313                     if (rs->completions[i][j] != rs->completions[0][j])
 314                         max_prefix = j;
 315                 }
 316             }
 317             if (len > max_width)
 318                 max_width = len;
 319         }
 320         if (max_prefix > 0)
 321             for(i = rs->completion_index; i < max_prefix; i++) {
 322                 readline_insert_char(rs, rs->completions[0][i]);
 323             }
 324         max_width += 2;
 325         if (max_width < 10)
 326             max_width = 10;
 327         else if (max_width > 80)
 328             max_width = 80;
 329         nb_cols = 80 / max_width;
 330         j = 0;
 331         for(i = 0; i < rs->nb_completions; i++) {
 332             monitor_printf(rs->mon, "%-*s", max_width, rs->completions[i]);
 333             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
 334                 monitor_printf(rs->mon, "\n");
 335                 j = 0;
 336             }
 337         }
 338         readline_show_prompt(rs);
 339     }
 340     for (i = 0; i < rs->nb_completions; i++) {
 341         g_free(rs->completions[i]);
 342     }
 343 }
 344
 345 /* return true if command handled */
 346 void readline_handle_byte(ReadLineState *rs, int ch)
 347 {
 348     switch(rs->esc_state) {
 349     case IS_NORM:
 350         switch(ch) {
 351         case 1:
 352             readline_bol(rs);
 353             break;
 354         case 4:
 355             readline_delete_char(rs);
 356             break;
 357         case 5:
 358             readline_eol(rs);
 359             break;
 360         case 9:
 361             readline_completion(rs);
 362             break;
 363         case 10:
 364         case 13:
 365             rs->cmd_buf[rs->cmd_buf_size] = '\0';
 366             if (!rs->read_password)
 367                 readline_hist_add(rs, rs->cmd_buf);
 368             monitor_printf(rs->mon, "\n");
 369             rs->cmd_buf_index = 0;
 370             rs->cmd_buf_size = 0;
 371             rs->last_cmd_buf_index = 0;
 372             rs->last_cmd_buf_size = 0;
 373             rs->readline_func(rs->mon, rs->cmd_buf, rs->readline_opaque);
 374             break;
 375         case 23:
 376             /* ^W */
 377             readline_backword(rs);
 378             break;
 379         case 27:
 380             rs->esc_state = IS_ESC;
 381             break;
 382         case 127:
 383         case 8:
 384             readline_backspace(rs);
 385             break;
 386         case 155:
 387             rs->esc_state = IS_CSI;
 388             break;
 389         default:
 390             if (ch >= 32) {
 391                 readline_insert_char(rs, ch);
 392             }
 393             break;
 394         }
 395         break;
 396     case IS_ESC:
 397         if (ch == '[') {
 398             rs->esc_state = IS_CSI;
 399             rs->esc_param = 0;
 400         } else {
 401             rs->esc_state = IS_NORM;
 402         }
 403         break;
 404     case IS_CSI:
 405         switch(ch) {
 406         case 'A':
 407         case 'F':
 408             readline_up_char(rs);
 409             break;
 410         case 'B':
 411         case 'E':
 412             readline_down_char(rs);
 413             break;
 414         case 'D':
 415             readline_backward_char(rs);
 416             break;
 417         case 'C':
 418             readline_forward_char(rs);
 419             break;
 420         case '0' ... '9':
 421             rs->esc_param = rs->esc_param * 10 + (ch - '0');
 422             goto the_end;
 423         case '~':
 424             switch(rs->esc_param) {
 425             case 1:
 426                 readline_bol(rs);
 427                 break;
 428             case 3:
 429                 readline_delete_char(rs);
 430                 break;
 431             case 4:
 432                 readline_eol(rs);
 433                 break;
 434             }
 435             break;
 436         default:
 437             break;
 438         }
 439         rs->esc_state = IS_NORM;
 440     the_end:
 441         break;
 442     }
 443     readline_update(rs);
 444 }
 445
 446 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
 447                     ReadLineFunc *readline_func, void *opaque)
 448 {
 449     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
 450     rs->readline_func = readline_func;
 451     rs->readline_opaque = opaque;
 452     rs->read_password = read_password;
 453     readline_restart(rs);
 454 }
 455
 456 void readline_restart(ReadLineState *rs)
 457 {
 458     rs->cmd_buf_index = 0;
 459     rs->cmd_buf_size = 0;
 460 }
 461
 462 const char *readline_get_history(ReadLineState *rs, unsigned int index)
 463 {
 464     if (index >= READLINE_MAX_CMDS)
 465         return NULL;
 466     return rs->history[index];
 467 }
 468
 469 ReadLineState *readline_init(Monitor *mon,
 470                              ReadLineCompletionFunc *completion_finder)
 471 {
 472     ReadLineState *rs = g_malloc0(sizeof(*rs));
 473
 474     rs->hist_entry = -1;
 475     rs->mon = mon;
 476     rs->completion_finder = completion_finder;
 477
 478     return rs;
 479 }