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 "readline.h"
  25 #include "monitor.h"
  26
  27 #define IS_NORM 0
  28 #define IS_ESC  1
  29 #define IS_CSI  2
  30
  31 #define printf do_not_use_printf
  32
  33 void readline_show_prompt(ReadLineState *rs)
  34 {
  35     monitor_printf(rs->mon, "%s", rs->prompt);
  36     monitor_flush(rs->mon);
  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             monitor_printf(rs->mon, "\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                 monitor_printf(rs->mon, "*");
  57         } else {
  58             monitor_printf(rs->mon, "%s", rs->cmd_buf);
  59         }
  60         monitor_printf(rs->mon, "\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                 monitor_printf(rs->mon, "\033[C");
  70             }
  71         } else {
  72             delta = -delta;
  73             for(i = 0;i < delta; i++) {
  74                 monitor_printf(rs->mon, "\033[D");
  75             }
  76         }
  77         rs->last_cmd_buf_index = rs->cmd_buf_index;
  78     }
  79     monitor_flush(rs->mon);
  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 == READLINE_MAX_CMDS - 1 || rs->hist_entry == -1)
 200         return;
 201     if (rs->history[++rs->hist_entry] != NULL) {
 202         pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
 203                 rs->history[rs->hist_entry]);
 204     } else {
 205         rs->hist_entry = -1;
 206     }
 207     rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
 208 }
 209
 210 static void readline_hist_add(ReadLineState *rs, const char *cmdline)
 211 {
 212     char *hist_entry, *new_entry;
 213     int idx;
 214
 215     if (cmdline[0] == '\0')
 216         return;
 217     new_entry = NULL;
 218     if (rs->hist_entry != -1) {
 219         /* We were editing an existing history entry: replace it */
 220         hist_entry = rs->history[rs->hist_entry];
 221         idx = rs->hist_entry;
 222         if (strcmp(hist_entry, cmdline) == 0) {
 223             goto same_entry;
 224         }
 225     }
 226     /* Search cmdline in history buffers */
 227     for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
 228         hist_entry = rs->history[idx];
 229         if (hist_entry == NULL)
 230             break;
 231         if (strcmp(hist_entry, cmdline) == 0) {
 232         same_entry:
 233             new_entry = hist_entry;
 234             /* Put this entry at the end of history */
 235             memmove(&rs->history[idx], &rs->history[idx + 1],
 236                     (READLINE_MAX_CMDS - idx + 1) * sizeof(char *));
 237             rs->history[READLINE_MAX_CMDS - 1] = NULL;
 238             for (; idx < READLINE_MAX_CMDS; idx++) {
 239                 if (rs->history[idx] == NULL)
 240                     break;
 241             }
 242             break;
 243         }
 244     }
 245     if (idx == READLINE_MAX_CMDS) {
 246         /* Need to get one free slot */
 247         free(rs->history[0]);
 248         memcpy(rs->history, &rs->history[1],
 249                (READLINE_MAX_CMDS - 1) * sizeof(char *));
 250         rs->history[READLINE_MAX_CMDS - 1] = NULL;
 251         idx = READLINE_MAX_CMDS - 1;
 252     }
 253     if (new_entry == NULL)
 254         new_entry = strdup(cmdline);
 255     rs->history[idx] = new_entry;
 256     rs->hist_entry = -1;
 257 }
 258
 259 /* completion support */
 260
 261 void readline_add_completion(ReadLineState *rs, const char *str)
 262 {
 263     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
 264         rs->completions[rs->nb_completions++] = qemu_strdup(str);
 265     }
 266 }
 267
 268 void readline_set_completion_index(ReadLineState *rs, int index)
 269 {
 270     rs->completion_index = index;
 271 }
 272
 273 static void readline_completion(ReadLineState *rs)
 274 {
 275     Monitor *mon = cur_mon;
 276     int len, i, j, max_width, nb_cols, max_prefix;
 277     char *cmdline;
 278
 279     rs->nb_completions = 0;
 280
 281     cmdline = qemu_malloc(rs->cmd_buf_index + 1);
 282     memcpy(cmdline, rs->cmd_buf, rs->cmd_buf_index);
 283     cmdline[rs->cmd_buf_index] = '\0';
 284     rs->completion_finder(cmdline);
 285     qemu_free(cmdline);
 286
 287     /* no completion found */
 288     if (rs->nb_completions <= 0)
 289         return;
 290     if (rs->nb_completions == 1) {
 291         len = strlen(rs->completions[0]);
 292         for(i = rs->completion_index; i < len; i++) {
 293             readline_insert_char(rs, rs->completions[0][i]);
 294         }
 295         /* extra space for next argument. XXX: make it more generic */
 296         if (len > 0 && rs->completions[0][len - 1] != '/')
 297             readline_insert_char(rs, ' ');
 298     } else {
 299         monitor_printf(mon, "\n");
 300         max_width = 0;
 301         max_prefix = 0;
 302         for(i = 0; i < rs->nb_completions; i++) {
 303             len = strlen(rs->completions[i]);
 304             if (i==0) {
 305                 max_prefix = len;
 306             } else {
 307                 if (len < max_prefix)
 308                     max_prefix = len;
 309                 for(j=0; j<max_prefix; j++) {
 310                     if (rs->completions[i][j] != rs->completions[0][j])
 311                         max_prefix = j;
 312                 }
 313             }
 314             if (len > max_width)
 315                 max_width = len;
 316         }
 317         if (max_prefix > 0)
 318             for(i = rs->completion_index; i < max_prefix; i++) {
 319                 readline_insert_char(rs, rs->completions[0][i]);
 320             }
 321         max_width += 2;
 322         if (max_width < 10)
 323             max_width = 10;
 324         else if (max_width > 80)
 325             max_width = 80;
 326         nb_cols = 80 / max_width;
 327         j = 0;
 328         for(i = 0; i < rs->nb_completions; i++) {
 329             monitor_printf(rs->mon, "%-*s", max_width, rs->completions[i]);
 330             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
 331                 monitor_printf(rs->mon, "\n");
 332                 j = 0;
 333             }
 334         }
 335         readline_show_prompt(rs);
 336     }
 337 }
 338
 339 /* return true if command handled */
 340 void readline_handle_byte(ReadLineState *rs, int ch)
 341 {
 342     switch(rs->esc_state) {
 343     case IS_NORM:
 344         switch(ch) {
 345         case 1:
 346             readline_bol(rs);
 347             break;
 348         case 4:
 349             readline_delete_char(rs);
 350             break;
 351         case 5:
 352             readline_eol(rs);
 353             break;
 354         case 9:
 355             readline_completion(rs);
 356             break;
 357         case 10:
 358         case 13:
 359             rs->cmd_buf[rs->cmd_buf_size] = '\0';
 360             if (!rs->read_password)
 361                 readline_hist_add(rs, rs->cmd_buf);
 362             monitor_printf(rs->mon, "\n");
 363             rs->cmd_buf_index = 0;
 364             rs->cmd_buf_size = 0;
 365             rs->last_cmd_buf_index = 0;
 366             rs->last_cmd_buf_size = 0;
 367             rs->readline_func(rs->mon, rs->cmd_buf, rs->readline_opaque);
 368             break;
 369         case 23:
 370             /* ^W */
 371             readline_backword(rs);
 372             break;
 373         case 27:
 374             rs->esc_state = IS_ESC;
 375             break;
 376         case 127:
 377         case 8:
 378             readline_backspace(rs);
 379             break;
 380         case 155:
 381             rs->esc_state = IS_CSI;
 382             break;
 383         default:
 384             if (ch >= 32) {
 385                 readline_insert_char(rs, ch);
 386             }
 387             break;
 388         }
 389         break;
 390     case IS_ESC:
 391         if (ch == '[') {
 392             rs->esc_state = IS_CSI;
 393             rs->esc_param = 0;
 394         } else {
 395             rs->esc_state = IS_NORM;
 396         }
 397         break;
 398     case IS_CSI:
 399         switch(ch) {
 400         case 'A':
 401         case 'F':
 402             readline_up_char(rs);
 403             break;
 404         case 'B':
 405         case 'E':
 406             readline_down_char(rs);
 407             break;
 408         case 'D':
 409             readline_backward_char(rs);
 410             break;
 411         case 'C':
 412             readline_forward_char(rs);
 413             break;
 414         case '0' ... '9':
 415             rs->esc_param = rs->esc_param * 10 + (ch - '0');
 416             goto the_end;
 417         case '~':
 418             switch(rs->esc_param) {
 419             case 1:
 420                 readline_bol(rs);
 421                 break;
 422             case 3:
 423                 readline_delete_char(rs);
 424                 break;
 425             case 4:
 426                 readline_eol(rs);
 427                 break;
 428             }
 429             break;
 430         default:
 431             break;
 432         }
 433         rs->esc_state = IS_NORM;
 434     the_end:
 435         break;
 436     }
 437     readline_update(rs);
 438 }
 439
 440 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
 441                     ReadLineFunc *readline_func, void *opaque)
 442 {
 443     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
 444     rs->readline_func = readline_func;
 445     rs->readline_opaque = opaque;
 446     rs->read_password = read_password;
 447     readline_restart(rs);
 448 }
 449
 450 void readline_restart(ReadLineState *rs)
 451 {
 452     rs->cmd_buf_index = 0;
 453     rs->cmd_buf_size = 0;
 454 }
 455
 456 const char *readline_get_history(ReadLineState *rs, unsigned int index)
 457 {
 458     if (index >= READLINE_MAX_CMDS)
 459         return NULL;
 460     return rs->history[index];
 461 }
 462
 463 ReadLineState *readline_init(Monitor *mon,
 464                              ReadLineCompletionFunc *completion_finder)
 465 {
 466     ReadLineState *rs = qemu_mallocz(sizeof(*rs));
 467
 468     if (!rs)
 469         return NULL;
 470
 471     rs->hist_entry = -1;
 472     rs->mon = mon;
 473     rs->completion_finder = completion_finder;
 474
 475     return rs;
 476 }