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 static void term_show_prompt2(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 static void term_show_prompt(void)
  70 {
  71     term_show_prompt2();
  72     term_cmd_buf_index = 0;
  73     term_cmd_buf_size = 0;
  74 }
  75
  76 /* update the displayed command line */
  77 static void term_update(void)
  78 {
  79     int i, delta, len;
  80
  81     if (term_cmd_buf_size != term_last_cmd_buf_size ||
  82         memcmp(term_cmd_buf, term_last_cmd_buf, term_cmd_buf_size) != 0) {
  83         for(i = 0; i < term_last_cmd_buf_index; i++) {
  84             term_printf("\033[D");
  85         }
  86         term_cmd_buf[term_cmd_buf_size] = '\0';
  87         if (term_is_password) {
  88             len = strlen(term_cmd_buf);
  89             for(i = 0; i < len; i++)
  90                 term_printf("*");
  91         } else {
  92             term_printf("%s", term_cmd_buf);
  93         }
  94         term_printf("\033[K");
  95         memcpy(term_last_cmd_buf, term_cmd_buf, term_cmd_buf_size);
  96         term_last_cmd_buf_size = term_cmd_buf_size;
  97         term_last_cmd_buf_index = term_cmd_buf_size;
  98     }
  99     if (term_cmd_buf_index != term_last_cmd_buf_index) {
 100         delta = term_cmd_buf_index - term_last_cmd_buf_index;
 101         if (delta > 0) {
 102             for(i = 0;i < delta; i++) {
 103                 term_printf("\033[C");
 104             }
 105         } else {
 106             delta = -delta;
 107             for(i = 0;i < delta; i++) {
 108                 term_printf("\033[D");
 109             }
 110         }
 111         term_last_cmd_buf_index = term_cmd_buf_index;
 112     }
 113     term_flush();
 114 }
 115
 116 static void term_insert_char(int ch)
 117 {
 118     if (term_cmd_buf_index < TERM_CMD_BUF_SIZE) {
 119         memmove(term_cmd_buf + term_cmd_buf_index + 1,
 120                 term_cmd_buf + term_cmd_buf_index,
 121                 term_cmd_buf_size - term_cmd_buf_index);
 122         term_cmd_buf[term_cmd_buf_index] = ch;
 123         term_cmd_buf_size++;
 124         term_cmd_buf_index++;
 125     }
 126 }
 127
 128 static void term_backward_char(void)
 129 {
 130     if (term_cmd_buf_index > 0) {
 131         term_cmd_buf_index--;
 132     }
 133 }
 134
 135 static void term_forward_char(void)
 136 {
 137     if (term_cmd_buf_index < term_cmd_buf_size) {
 138         term_cmd_buf_index++;
 139     }
 140 }
 141
 142 static void term_delete_char(void)
 143 {
 144     if (term_cmd_buf_index < term_cmd_buf_size) {
 145         memmove(term_cmd_buf + term_cmd_buf_index,
 146                 term_cmd_buf + term_cmd_buf_index + 1,
 147                 term_cmd_buf_size - term_cmd_buf_index - 1);
 148         term_cmd_buf_size--;
 149     }
 150 }
 151
 152 static void term_backspace(void)
 153 {
 154     if (term_cmd_buf_index > 0) {
 155         term_backward_char();
 156         term_delete_char();
 157     }
 158 }
 159
 160 static void term_backword(void)
 161 {
 162     int start;
 163
 164     if (term_cmd_buf_index == 0 || term_cmd_buf_index > term_cmd_buf_size) {
 165         return;
 166     }
 167
 168     start = term_cmd_buf_index - 1;
 169
 170     /* find first word (backwards) */
 171     while (start > 0) {
 172         if (!qemu_isspace(term_cmd_buf[start])) {
 173             break;
 174         }
 175
 176         --start;
 177     }
 178
 179     /* find first space (backwards) */
 180     while (start > 0) {
 181         if (qemu_isspace(term_cmd_buf[start])) {
 182             ++start;
 183             break;
 184         }
 185
 186         --start;
 187     }
 188
 189     /* remove word */
 190     if (start < term_cmd_buf_index) {
 191         memmove(term_cmd_buf + start,
 192                 term_cmd_buf + term_cmd_buf_index,
 193                 term_cmd_buf_size - term_cmd_buf_index);
 194         term_cmd_buf_size -= term_cmd_buf_index - start;
 195         term_cmd_buf_index = start;
 196     }
 197 }
 198
 199 static void term_bol(void)
 200 {
 201     term_cmd_buf_index = 0;
 202 }
 203
 204 static void term_eol(void)
 205 {
 206     term_cmd_buf_index = term_cmd_buf_size;
 207 }
 208
 209 static void term_up_char(void)
 210 {
 211     int idx;
 212
 213     if (term_hist_entry == 0)
 214         return;
 215     if (term_hist_entry == -1) {
 216         /* Find latest entry */
 217         for (idx = 0; idx < TERM_MAX_CMDS; idx++) {
 218             if (term_history[idx] == NULL)
 219                 break;
 220         }
 221         term_hist_entry = idx;
 222     }
 223     term_hist_entry--;
 224     if (term_hist_entry >= 0) {
 225         pstrcpy(term_cmd_buf, sizeof(term_cmd_buf),
 226                 term_history[term_hist_entry]);
 227         term_cmd_buf_index = term_cmd_buf_size = strlen(term_cmd_buf);
 228     }
 229 }
 230
 231 static void term_down_char(void)
 232 {
 233     if (term_hist_entry == TERM_MAX_CMDS - 1 || term_hist_entry == -1)
 234         return;
 235     if (term_history[++term_hist_entry] != NULL) {
 236         pstrcpy(term_cmd_buf, sizeof(term_cmd_buf),
 237                 term_history[term_hist_entry]);
 238     } else {
 239         term_hist_entry = -1;
 240     }
 241     term_cmd_buf_index = term_cmd_buf_size = strlen(term_cmd_buf);
 242 }
 243
 244 static void term_hist_add(const char *cmdline)
 245 {
 246     char *hist_entry, *new_entry;
 247     int idx;
 248
 249     if (cmdline[0] == '\0')
 250         return;
 251     new_entry = NULL;
 252     if (term_hist_entry != -1) {
 253         /* We were editing an existing history entry: replace it */
 254         hist_entry = term_history[term_hist_entry];
 255         idx = term_hist_entry;
 256         if (strcmp(hist_entry, cmdline) == 0) {
 257             goto same_entry;
 258         }
 259     }
 260     /* Search cmdline in history buffers */
 261     for (idx = 0; idx < TERM_MAX_CMDS; idx++) {
 262         hist_entry = term_history[idx];
 263         if (hist_entry == NULL)
 264             break;
 265         if (strcmp(hist_entry, cmdline) == 0) {
 266         same_entry:
 267             new_entry = hist_entry;
 268             /* Put this entry at the end of history */
 269             memmove(&term_history[idx], &term_history[idx + 1],
 270                     (TERM_MAX_CMDS - idx + 1) * sizeof(char *));
 271             term_history[TERM_MAX_CMDS - 1] = NULL;
 272             for (; idx < TERM_MAX_CMDS; idx++) {
 273                 if (term_history[idx] == NULL)
 274                     break;
 275             }
 276             break;
 277         }
 278     }
 279     if (idx == TERM_MAX_CMDS) {
 280         /* Need to get one free slot */
 281         free(term_history[0]);
 282         memcpy(term_history, &term_history[1],
 283                (TERM_MAX_CMDS - 1) * sizeof(char *));
 284         term_history[TERM_MAX_CMDS - 1] = NULL;
 285         idx = TERM_MAX_CMDS - 1;
 286     }
 287     if (new_entry == NULL)
 288         new_entry = strdup(cmdline);
 289     term_history[idx] = new_entry;
 290     term_hist_entry = -1;
 291 }
 292
 293 /* completion support */
 294
 295 void add_completion(const char *str)
 296 {
 297     if (nb_completions < NB_COMPLETIONS_MAX) {
 298         completions[nb_completions++] = qemu_strdup(str);
 299     }
 300 }
 301
 302 static void term_completion(void)
 303 {
 304     int len, i, j, max_width, nb_cols, max_prefix;
 305     char *cmdline;
 306
 307     nb_completions = 0;
 308
 309     cmdline = qemu_malloc(term_cmd_buf_index + 1);
 310     if (!cmdline)
 311         return;
 312     memcpy(cmdline, term_cmd_buf, term_cmd_buf_index);
 313     cmdline[term_cmd_buf_index] = '\0';
 314     readline_find_completion(cmdline);
 315     qemu_free(cmdline);
 316
 317     /* no completion found */
 318     if (nb_completions <= 0)
 319         return;
 320     if (nb_completions == 1) {
 321         len = strlen(completions[0]);
 322         for(i = completion_index; i < len; i++) {
 323             term_insert_char(completions[0][i]);
 324         }
 325         /* extra space for next argument. XXX: make it more generic */
 326         if (len > 0 && completions[0][len - 1] != '/')
 327             term_insert_char(' ');
 328     } else {
 329         term_printf("\n");
 330         max_width = 0;
 331         max_prefix = 0;
 332         for(i = 0; i < nb_completions; i++) {
 333             len = strlen(completions[i]);
 334             if (i==0) {
 335                 max_prefix = len;
 336             } else {
 337                 if (len < max_prefix)
 338                     max_prefix = len;
 339                 for(j=0; j<max_prefix; j++) {
 340                     if (completions[i][j] != completions[0][j])
 341                         max_prefix = j;
 342                 }
 343             }
 344             if (len > max_width)
 345                 max_width = len;
 346         }
 347         if (max_prefix > 0)
 348             for(i = completion_index; i < max_prefix; i++) {
 349                 term_insert_char(completions[0][i]);
 350             }
 351         max_width += 2;
 352         if (max_width < 10)
 353             max_width = 10;
 354         else if (max_width > 80)
 355             max_width = 80;
 356         nb_cols = 80 / max_width;
 357         j = 0;
 358         for(i = 0; i < nb_completions; i++) {
 359             term_printf("%-*s", max_width, completions[i]);
 360             if (++j == nb_cols || i == (nb_completions - 1)) {
 361                 term_printf("\n");
 362                 j = 0;
 363             }
 364         }
 365         term_show_prompt2();
 366     }
 367 }
 368
 369 /* return true if command handled */
 370 void readline_handle_byte(int ch)
 371 {
 372     switch(term_esc_state) {
 373     case IS_NORM:
 374         switch(ch) {
 375         case 1:
 376             term_bol();
 377             break;
 378         case 4:
 379             term_delete_char();
 380             break;
 381         case 5:
 382             term_eol();
 383             break;
 384         case 9:
 385             term_completion();
 386             break;
 387         case 10:
 388         case 13:
 389             term_cmd_buf[term_cmd_buf_size] = '\0';
 390             if (!term_is_password)
 391                 term_hist_add(term_cmd_buf);
 392             term_printf("\n");
 393             term_cmd_buf_index = 0;
 394             term_cmd_buf_size = 0;
 395             term_last_cmd_buf_index = 0;
 396             term_last_cmd_buf_size = 0;
 397             /* NOTE: readline_start can be called here */
 398             term_readline_func(term_readline_opaque, term_cmd_buf);
 399             break;
 400         case 23:
 401             /* ^W */
 402             term_backword();
 403             break;
 404         case 27:
 405             term_esc_state = IS_ESC;
 406             break;
 407         case 127:
 408         case 8:
 409             term_backspace();
 410             break;
 411         case 155:
 412             term_esc_state = IS_CSI;
 413             break;
 414         default:
 415             if (ch >= 32) {
 416                 term_insert_char(ch);
 417             }
 418             break;
 419         }
 420         break;
 421     case IS_ESC:
 422         if (ch == '[') {
 423             term_esc_state = IS_CSI;
 424             term_esc_param = 0;
 425         } else {
 426             term_esc_state = IS_NORM;
 427         }
 428         break;
 429     case IS_CSI:
 430         switch(ch) {
 431         case 'A':
 432         case 'F':
 433             term_up_char();
 434             break;
 435         case 'B':
 436         case 'E':
 437             term_down_char();
 438             break;
 439         case 'D':
 440             term_backward_char();
 441             break;
 442         case 'C':
 443             term_forward_char();
 444             break;
 445         case '0' ... '9':
 446             term_esc_param = term_esc_param * 10 + (ch - '0');
 447             goto the_end;
 448         case '~':
 449             switch(term_esc_param) {
 450             case 1:
 451                 term_bol();
 452                 break;
 453             case 3:
 454                 term_delete_char();
 455                 break;
 456             case 4:
 457                 term_eol();
 458                 break;
 459             }
 460             break;
 461         default:
 462             break;
 463         }
 464         term_esc_state = IS_NORM;
 465     the_end:
 466         break;
 467     }
 468     term_update();
 469 }
 470
 471 void readline_start(const char *prompt, int is_password,
 472                     ReadLineFunc *readline_func, void *opaque)
 473 {
 474     pstrcpy(term_prompt, sizeof(term_prompt), prompt);
 475     term_readline_func = readline_func;
 476     term_readline_opaque = opaque;
 477     term_is_password = is_password;
 478     term_show_prompt();
 479 }
 480
 481 const char *readline_get_history(unsigned int index)
 482 {
 483     if (index >= TERM_MAX_CMDS)
 484         return NULL;
 485     return term_history[index];
 486 }