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 "qemu-common.h"
  25 #include "console.h"
  26
  27 #define TERM_CMD_BUF_SIZE 4095
  28 #define TERM_MAX_CMDS 64
  29 #define NB_COMPLETIONS_MAX 256
  30
  31 #define IS_NORM 0
  32 #define IS_ESC  1
  33 #define IS_CSI  2
  34
  35 #define printf do_not_use_printf
  36
  37 static char term_cmd_buf[TERM_CMD_BUF_SIZE + 1];
  38 static int term_cmd_buf_index;
  39 static int term_cmd_buf_size;
  40
  41 static char term_last_cmd_buf[TERM_CMD_BUF_SIZE + 1];
  42 static int term_last_cmd_buf_index;
  43 static int term_last_cmd_buf_size;
  44
  45 static int term_esc_state;
  46 static int term_esc_param;
  47
  48 static char *term_history[TERM_MAX_CMDS];
  49 static int term_hist_entry = -1;
  50
  51 static int nb_completions;
  52 int completion_index;
  53 static char *completions[NB_COMPLETIONS_MAX];
  54
  55 static ReadLineFunc *term_readline_func;
  56 static int term_is_password;
  57 static char term_prompt[256];
  58 static void *term_readline_opaque;
  59
  60 void readline_show_prompt(void)
  61 {
  62     term_printf("%s", term_prompt);
  63     term_flush();
  64     term_last_cmd_buf_index = 0;
  65     term_last_cmd_buf_size = 0;
  66     term_esc_state = IS_NORM;
  67 }
  68
  69 /* update the displayed command line */
  70 static void term_update(void)
  71 {
  72     int i, delta, len;
  73
  74     if (term_cmd_buf_size != term_last_cmd_buf_size ||
  75         memcmp(term_cmd_buf, term_last_cmd_buf, term_cmd_buf_size) != 0) {
  76         for(i = 0; i < term_last_cmd_buf_index; i++) {
  77             term_printf("\033[D");
  78         }
  79         term_cmd_buf[term_cmd_buf_size] = '\0';
  80         if (term_is_password) {
  81             len = strlen(term_cmd_buf);
  82             for(i = 0; i < len; i++)
  83                 term_printf("*");
  84         } else {
  85             term_printf("%s", term_cmd_buf);
  86         }
  87         term_printf("\033[K");
  88         memcpy(term_last_cmd_buf, term_cmd_buf, term_cmd_buf_size);
  89         term_last_cmd_buf_size = term_cmd_buf_size;
  90         term_last_cmd_buf_index = term_cmd_buf_size;
  91     }
  92     if (term_cmd_buf_index != term_last_cmd_buf_index) {
  93         delta = term_cmd_buf_index - term_last_cmd_buf_index;
  94         if (delta > 0) {
  95             for(i = 0;i < delta; i++) {
  96                 term_printf("\033[C");
  97             }
  98         } else {
  99             delta = -delta;
 100             for(i = 0;i < delta; i++) {
 101                 term_printf("\033[D");
 102             }
 103         }
 104         term_last_cmd_buf_index = term_cmd_buf_index;
 105     }
 106     term_flush();
 107 }
 108
 109 static void term_insert_char(int ch)
 110 {
 111     if (term_cmd_buf_index < TERM_CMD_BUF_SIZE) {
 112         memmove(term_cmd_buf + term_cmd_buf_index + 1,
 113                 term_cmd_buf + term_cmd_buf_index,
 114                 term_cmd_buf_size - term_cmd_buf_index);
 115         term_cmd_buf[term_cmd_buf_index] = ch;
 116         term_cmd_buf_size++;
 117         term_cmd_buf_index++;
 118     }
 119 }
 120
 121 static void term_backward_char(void)
 122 {
 123     if (term_cmd_buf_index > 0) {
 124         term_cmd_buf_index--;
 125     }
 126 }
 127
 128 static void term_forward_char(void)
 129 {
 130     if (term_cmd_buf_index < term_cmd_buf_size) {
 131         term_cmd_buf_index++;
 132     }
 133 }
 134
 135 static void term_delete_char(void)
 136 {
 137     if (term_cmd_buf_index < term_cmd_buf_size) {
 138         memmove(term_cmd_buf + term_cmd_buf_index,
 139                 term_cmd_buf + term_cmd_buf_index + 1,
 140                 term_cmd_buf_size - term_cmd_buf_index - 1);
 141         term_cmd_buf_size--;
 142     }
 143 }
 144
 145 static void term_backspace(void)
 146 {
 147     if (term_cmd_buf_index > 0) {
 148         term_backward_char();
 149         term_delete_char();
 150     }
 151 }
 152
 153 static void term_backword(void)
 154 {
 155     int start;
 156
 157     if (term_cmd_buf_index == 0 || term_cmd_buf_index > term_cmd_buf_size) {
 158         return;
 159     }
 160
 161     start = term_cmd_buf_index - 1;
 162
 163     /* find first word (backwards) */
 164     while (start > 0) {
 165         if (!qemu_isspace(term_cmd_buf[start])) {
 166             break;
 167         }
 168
 169         --start;
 170     }
 171
 172     /* find first space (backwards) */
 173     while (start > 0) {
 174         if (qemu_isspace(term_cmd_buf[start])) {
 175             ++start;
 176             break;
 177         }
 178
 179         --start;
 180     }
 181
 182     /* remove word */
 183     if (start < term_cmd_buf_index) {
 184         memmove(term_cmd_buf + start,
 185                 term_cmd_buf + term_cmd_buf_index,
 186                 term_cmd_buf_size - term_cmd_buf_index);
 187         term_cmd_buf_size -= term_cmd_buf_index - start;
 188         term_cmd_buf_index = start;
 189     }
 190 }
 191
 192 static void term_bol(void)
 193 {
 194     term_cmd_buf_index = 0;
 195 }
 196
 197 static void term_eol(void)
 198 {
 199     term_cmd_buf_index = term_cmd_buf_size;
 200 }
 201
 202 static void term_up_char(void)
 203 {
 204     int idx;
 205
 206     if (term_hist_entry == 0)
 207         return;
 208     if (term_hist_entry == -1) {
 209         /* Find latest entry */
 210         for (idx = 0; idx < TERM_MAX_CMDS; idx++) {
 211             if (term_history[idx] == NULL)
 212                 break;
 213         }
 214         term_hist_entry = idx;
 215     }
 216     term_hist_entry--;
 217     if (term_hist_entry >= 0) {
 218         pstrcpy(term_cmd_buf, sizeof(term_cmd_buf),
 219                 term_history[term_hist_entry]);
 220         term_cmd_buf_index = term_cmd_buf_size = strlen(term_cmd_buf);
 221     }
 222 }
 223
 224 static void term_down_char(void)
 225 {
 226     if (term_hist_entry == TERM_MAX_CMDS - 1 || term_hist_entry == -1)
 227         return;
 228     if (term_history[++term_hist_entry] != NULL) {
 229         pstrcpy(term_cmd_buf, sizeof(term_cmd_buf),
 230                 term_history[term_hist_entry]);
 231     } else {
 232         term_hist_entry = -1;
 233     }
 234     term_cmd_buf_index = term_cmd_buf_size = strlen(term_cmd_buf);
 235 }
 236
 237 static void term_hist_add(const char *cmdline)
 238 {
 239     char *hist_entry, *new_entry;
 240     int idx;
 241
 242     if (cmdline[0] == '\0')
 243         return;
 244     new_entry = NULL;
 245     if (term_hist_entry != -1) {
 246         /* We were editing an existing history entry: replace it */
 247         hist_entry = term_history[term_hist_entry];
 248         idx = term_hist_entry;
 249         if (strcmp(hist_entry, cmdline) == 0) {
 250             goto same_entry;
 251         }
 252     }
 253     /* Search cmdline in history buffers */
 254     for (idx = 0; idx < TERM_MAX_CMDS; idx++) {
 255         hist_entry = term_history[idx];
 256         if (hist_entry == NULL)
 257             break;
 258         if (strcmp(hist_entry, cmdline) == 0) {
 259         same_entry:
 260             new_entry = hist_entry;
 261             /* Put this entry at the end of history */
 262             memmove(&term_history[idx], &term_history[idx + 1],
 263                     (TERM_MAX_CMDS - idx + 1) * sizeof(char *));
 264             term_history[TERM_MAX_CMDS - 1] = NULL;
 265             for (; idx < TERM_MAX_CMDS; idx++) {
 266                 if (term_history[idx] == NULL)
 267                     break;
 268             }
 269             break;
 270         }
 271     }
 272     if (idx == TERM_MAX_CMDS) {
 273         /* Need to get one free slot */
 274         free(term_history[0]);
 275         memcpy(term_history, &term_history[1],
 276                (TERM_MAX_CMDS - 1) * sizeof(char *));
 277         term_history[TERM_MAX_CMDS - 1] = NULL;
 278         idx = TERM_MAX_CMDS - 1;
 279     }
 280     if (new_entry == NULL)
 281         new_entry = strdup(cmdline);
 282     term_history[idx] = new_entry;
 283     term_hist_entry = -1;
 284 }
 285
 286 /* completion support */
 287
 288 void add_completion(const char *str)
 289 {
 290     if (nb_completions < NB_COMPLETIONS_MAX) {
 291         completions[nb_completions++] = qemu_strdup(str);
 292     }
 293 }
 294
 295 static void term_completion(void)
 296 {
 297     int len, i, j, max_width, nb_cols, max_prefix;
 298     char *cmdline;
 299
 300     nb_completions = 0;
 301
 302     cmdline = qemu_malloc(term_cmd_buf_index + 1);
 303     memcpy(cmdline, term_cmd_buf, term_cmd_buf_index);
 304     cmdline[term_cmd_buf_index] = '\0';
 305     readline_find_completion(cmdline);
 306     qemu_free(cmdline);
 307
 308     /* no completion found */
 309     if (nb_completions <= 0)
 310         return;
 311     if (nb_completions == 1) {
 312         len = strlen(completions[0]);
 313         for(i = completion_index; i < len; i++) {
 314             term_insert_char(completions[0][i]);
 315         }
 316         /* extra space for next argument. XXX: make it more generic */
 317         if (len > 0 && completions[0][len - 1] != '/')
 318             term_insert_char(' ');
 319     } else {
 320         term_printf("\n");
 321         max_width = 0;
 322         max_prefix = 0;
 323         for(i = 0; i < nb_completions; i++) {
 324             len = strlen(completions[i]);
 325             if (i==0) {
 326                 max_prefix = len;
 327             } else {
 328                 if (len < max_prefix)
 329                     max_prefix = len;
 330                 for(j=0; j<max_prefix; j++) {
 331                     if (completions[i][j] != completions[0][j])
 332                         max_prefix = j;
 333                 }
 334             }
 335             if (len > max_width)
 336                 max_width = len;
 337         }
 338         if (max_prefix > 0)
 339             for(i = completion_index; i < max_prefix; i++) {
 340                 term_insert_char(completions[0][i]);
 341             }
 342         max_width += 2;
 343         if (max_width < 10)
 344             max_width = 10;
 345         else if (max_width > 80)
 346             max_width = 80;
 347         nb_cols = 80 / max_width;
 348         j = 0;
 349         for(i = 0; i < nb_completions; i++) {
 350             term_printf("%-*s", max_width, completions[i]);
 351             if (++j == nb_cols || i == (nb_completions - 1)) {
 352                 term_printf("\n");
 353                 j = 0;
 354             }
 355         }
 356         readline_show_prompt();
 357     }
 358 }
 359
 360 /* return true if command handled */
 361 void readline_handle_byte(int ch)
 362 {
 363     switch(term_esc_state) {
 364     case IS_NORM:
 365         switch(ch) {
 366         case 1:
 367             term_bol();
 368             break;
 369         case 4:
 370             term_delete_char();
 371             break;
 372         case 5:
 373             term_eol();
 374             break;
 375         case 9:
 376             term_completion();
 377             break;
 378         case 10:
 379         case 13:
 380             term_cmd_buf[term_cmd_buf_size] = '\0';
 381             if (!term_is_password)
 382                 term_hist_add(term_cmd_buf);
 383             term_printf("\n");
 384             term_cmd_buf_index = 0;
 385             term_cmd_buf_size = 0;
 386             term_last_cmd_buf_index = 0;
 387             term_last_cmd_buf_size = 0;
 388             /* NOTE: readline_start can be called here */
 389             term_readline_func(term_readline_opaque, term_cmd_buf);
 390             break;
 391         case 23:
 392             /* ^W */
 393             term_backword();
 394             break;
 395         case 27:
 396             term_esc_state = IS_ESC;
 397             break;
 398         case 127:
 399         case 8:
 400             term_backspace();
 401             break;
 402         case 155:
 403             term_esc_state = IS_CSI;
 404             break;
 405         default:
 406             if (ch >= 32) {
 407                 term_insert_char(ch);
 408             }
 409             break;
 410         }
 411         break;
 412     case IS_ESC:
 413         if (ch == '[') {
 414             term_esc_state = IS_CSI;
 415             term_esc_param = 0;
 416         } else {
 417             term_esc_state = IS_NORM;
 418         }
 419         break;
 420     case IS_CSI:
 421         switch(ch) {
 422         case 'A':
 423         case 'F':
 424             term_up_char();
 425             break;
 426         case 'B':
 427         case 'E':
 428             term_down_char();
 429             break;
 430         case 'D':
 431             term_backward_char();
 432             break;
 433         case 'C':
 434             term_forward_char();
 435             break;
 436         case '0' ... '9':
 437             term_esc_param = term_esc_param * 10 + (ch - '0');
 438             goto the_end;
 439         case '~':
 440             switch(term_esc_param) {
 441             case 1:
 442                 term_bol();
 443                 break;
 444             case 3:
 445                 term_delete_char();
 446                 break;
 447             case 4:
 448                 term_eol();
 449                 break;
 450             }
 451             break;
 452         default:
 453             break;
 454         }
 455         term_esc_state = IS_NORM;
 456     the_end:
 457         break;
 458     }
 459     term_update();
 460 }
 461
 462 void readline_start(const char *prompt, int is_password,
 463                     ReadLineFunc *readline_func, void *opaque)
 464 {
 465     pstrcpy(term_prompt, sizeof(term_prompt), prompt);
 466     term_readline_func = readline_func;
 467     term_readline_opaque = opaque;
 468     term_is_password = is_password;
 469     term_cmd_buf_index = 0;
 470     term_cmd_buf_size = 0;
 471 }
 472
 473 const char *readline_get_history(unsigned int index)
 474 {
 475     if (index >= TERM_MAX_CMDS)
 476         return NULL;
 477     return term_history[index];
 478 }