LXR qemu/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/osdep.h"
  26#include "qemu-common.h"
  27#include "qemu/readline.h"
  28#include "qemu/cutils.h"
  29
  30#define IS_NORM 0
  31#define IS_ESC  1
  32#define IS_CSI  2
  33#define IS_SS3  3
  34
  35void readline_show_prompt(ReadLineState *rs)
  36{
  37    rs->printf_func(rs->opaque, "%s", rs->prompt);
  38    rs->flush_func(rs->opaque);
  39    rs->last_cmd_buf_index = 0;
  40    rs->last_cmd_buf_size = 0;
  41    rs->esc_state = IS_NORM;
  42}
  43
  44/* update the displayed command line */
  45static void readline_update(ReadLineState *rs)
  46{
  47    int i, delta, len;
  48
  49    if (rs->cmd_buf_size != rs->last_cmd_buf_size ||
  50        memcmp(rs->cmd_buf, rs->last_cmd_buf, rs->cmd_buf_size) != 0) {
  51        for(i = 0; i < rs->last_cmd_buf_index; i++) {
  52            rs->printf_func(rs->opaque, "\033[D");
  53        }
  54        rs->cmd_buf[rs->cmd_buf_size] = '\0';
  55        if (rs->read_password) {
  56            len = strlen(rs->cmd_buf);
  57            for(i = 0; i < len; i++)
  58                rs->printf_func(rs->opaque, "*");
  59        } else {
  60            rs->printf_func(rs->opaque, "%s", rs->cmd_buf);
  61        }
  62        rs->printf_func(rs->opaque, "\033[K");
  63        memcpy(rs->last_cmd_buf, rs->cmd_buf, rs->cmd_buf_size);
  64        rs->last_cmd_buf_size = rs->cmd_buf_size;
  65        rs->last_cmd_buf_index = rs->cmd_buf_size;
  66    }
  67    if (rs->cmd_buf_index != rs->last_cmd_buf_index) {
  68        delta = rs->cmd_buf_index - rs->last_cmd_buf_index;
  69        if (delta > 0) {
  70            for(i = 0;i < delta; i++) {
  71                rs->printf_func(rs->opaque, "\033[C");
  72            }
  73        } else {
  74            delta = -delta;
  75            for(i = 0;i < delta; i++) {
  76                rs->printf_func(rs->opaque, "\033[D");
  77            }
  78        }
  79        rs->last_cmd_buf_index = rs->cmd_buf_index;
  80    }
  81    rs->flush_func(rs->opaque);
  82}
  83
  84static void readline_insert_char(ReadLineState *rs, int ch)
  85{
  86    if (rs->cmd_buf_index < READLINE_CMD_BUF_SIZE) {
  87        memmove(rs->cmd_buf + rs->cmd_buf_index + 1,
  88                rs->cmd_buf + rs->cmd_buf_index,
  89                rs->cmd_buf_size - rs->cmd_buf_index);
  90        rs->cmd_buf[rs->cmd_buf_index] = ch;
  91        rs->cmd_buf_size++;
  92        rs->cmd_buf_index++;
  93    }
  94}
  95
  96static void readline_backward_char(ReadLineState *rs)
  97{
  98    if (rs->cmd_buf_index > 0) {
  99        rs->cmd_buf_index--;
 100    }
 101}
 102
 103static void readline_forward_char(ReadLineState *rs)
 104{
 105    if (rs->cmd_buf_index < rs->cmd_buf_size) {
 106        rs->cmd_buf_index++;
 107    }
 108}
 109
 110static void readline_delete_char(ReadLineState *rs)
 111{
 112    if (rs->cmd_buf_index < rs->cmd_buf_size) {
 113        memmove(rs->cmd_buf + rs->cmd_buf_index,
 114                rs->cmd_buf + rs->cmd_buf_index + 1,
 115                rs->cmd_buf_size - rs->cmd_buf_index - 1);
 116        rs->cmd_buf_size--;
 117    }
 118}
 119
 120static void readline_backspace(ReadLineState *rs)
 121{
 122    if (rs->cmd_buf_index > 0) {
 123        readline_backward_char(rs);
 124        readline_delete_char(rs);
 125    }
 126}
 127
 128static void readline_backword(ReadLineState *rs)
 129{
 130    int start;
 131
 132    if (rs->cmd_buf_index == 0 || rs->cmd_buf_index > rs->cmd_buf_size) {
 133        return;
 134    }
 135
 136    start = rs->cmd_buf_index - 1;
 137
 138    /* find first word (backwards) */
 139    while (start > 0) {
 140        if (!qemu_isspace(rs->cmd_buf[start])) {
 141            break;
 142        }
 143
 144        --start;
 145    }
 146
 147    /* find first space (backwards) */
 148    while (start > 0) {
 149        if (qemu_isspace(rs->cmd_buf[start])) {
 150            ++start;
 151            break;
 152        }
 153
 154        --start;
 155    }
 156
 157    /* remove word */
 158    if (start < rs->cmd_buf_index) {
 159        memmove(rs->cmd_buf + start,
 160                rs->cmd_buf + rs->cmd_buf_index,
 161                rs->cmd_buf_size - rs->cmd_buf_index);
 162        rs->cmd_buf_size -= rs->cmd_buf_index - start;
 163        rs->cmd_buf_index = start;
 164    }
 165}
 166
 167static void readline_bol(ReadLineState *rs)
 168{
 169    rs->cmd_buf_index = 0;
 170}
 171
 172static void readline_eol(ReadLineState *rs)
 173{
 174    rs->cmd_buf_index = rs->cmd_buf_size;
 175}
 176
 177static void readline_up_char(ReadLineState *rs)
 178{
 179    int idx;
 180
 181    if (rs->hist_entry == 0)
 182        return;
 183    if (rs->hist_entry == -1) {
 184        /* Find latest entry */
 185        for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
 186            if (rs->history[idx] == NULL)
 187                break;
 188        }
 189        rs->hist_entry = idx;
 190    }
 191    rs->hist_entry--;
 192    if (rs->hist_entry >= 0) {
 193        pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
 194                rs->history[rs->hist_entry]);
 195        rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
 196    }
 197}
 198
 199static void readline_down_char(ReadLineState *rs)
 200{
 201    if (rs->hist_entry == -1)
 202        return;
 203    if (rs->hist_entry < READLINE_MAX_CMDS - 1 &&
 204        rs->history[++rs->hist_entry] != NULL) {
 205        pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
 206                rs->history[rs->hist_entry]);
 207    } else {
 208        rs->cmd_buf[0] = 0;
 209        rs->hist_entry = -1;
 210    }
 211    rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
 212}
 213
 214static void readline_hist_add(ReadLineState *rs, const char *cmdline)
 215{
 216    char *hist_entry, *new_entry;
 217    int idx;
 218
 219    if (cmdline[0] == '\0')
 220        return;
 221    new_entry = NULL;
 222    if (rs->hist_entry != -1) {
 223        /* We were editing an existing history entry: replace it */
 224        hist_entry = rs->history[rs->hist_entry];
 225        idx = rs->hist_entry;
 226        if (strcmp(hist_entry, cmdline) == 0) {
 227            goto same_entry;
 228        }
 229    }
 230    /* Search cmdline in history buffers */
 231    for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
 232        hist_entry = rs->history[idx];
 233        if (hist_entry == NULL)
 234            break;
 235        if (strcmp(hist_entry, cmdline) == 0) {
 236        same_entry:
 237            new_entry = hist_entry;
 238            /* Put this entry at the end of history */
 239            memmove(&rs->history[idx], &rs->history[idx + 1],
 240                    (READLINE_MAX_CMDS - (idx + 1)) * sizeof(char *));
 241            rs->history[READLINE_MAX_CMDS - 1] = NULL;
 242            for (; idx < READLINE_MAX_CMDS; idx++) {
 243                if (rs->history[idx] == NULL)
 244                    break;
 245            }
 246            break;
 247        }
 248    }
 249    if (idx == READLINE_MAX_CMDS) {
 250        /* Need to get one free slot */
 251        g_free(rs->history[0]);
 252        memmove(rs->history, &rs->history[1],
 253                (READLINE_MAX_CMDS - 1) * sizeof(char *));
 254        rs->history[READLINE_MAX_CMDS - 1] = NULL;
 255        idx = READLINE_MAX_CMDS - 1;
 256    }
 257    if (new_entry == NULL)
 258        new_entry = g_strdup(cmdline);
 259    rs->history[idx] = new_entry;
 260    rs->hist_entry = -1;
 261}
 262
 263/* completion support */
 264
 265void readline_add_completion(ReadLineState *rs, const char *str)
 266{
 267    if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
 268        int i;
 269        for (i = 0; i < rs->nb_completions; i++) {
 270            if (!strcmp(rs->completions[i], str)) {
 271                return;
 272            }
 273        }
 274        rs->completions[rs->nb_completions++] = g_strdup(str);
 275    }
 276}
 277
 278void readline_set_completion_index(ReadLineState *rs, int index)
 279{
 280    rs->completion_index = index;
 281}
 282
 283static int completion_comp(const void *a, const void *b)
 284{
 285    return strcmp(*(const char **) a, *(const char **) b);
 286}
 287
 288static void readline_completion(ReadLineState *rs)
 289{
 290    int len, i, j, max_width, nb_cols, max_prefix;
 291    char *cmdline;
 292
 293    rs->nb_completions = 0;
 294
 295    cmdline = g_strndup(rs->cmd_buf, rs->cmd_buf_index);
 296    rs->completion_finder(rs->opaque, cmdline);
 297    g_free(cmdline);
 298
 299    /* no completion found */
 300    if (rs->nb_completions <= 0)
 301        return;
 302    if (rs->nb_completions == 1) {
 303        len = strlen(rs->completions[0]);
 304        for(i = rs->completion_index; i < len; i++) {
 305            readline_insert_char(rs, rs->completions[0][i]);
 306        }
 307        /* extra space for next argument. XXX: make it more generic */
 308        if (len > 0 && rs->completions[0][len - 1] != '/')
 309            readline_insert_char(rs, ' ');
 310    } else {
 311        qsort(rs->completions, rs->nb_completions, sizeof(char *),
 312              completion_comp);
 313        rs->printf_func(rs->opaque, "\n");
 314        max_width = 0;
 315        max_prefix = 0; 
 316        for(i = 0; i < rs->nb_completions; i++) {
 317            len = strlen(rs->completions[i]);
 318            if (i==0) {
 319                max_prefix = len;
 320            } else {
 321                if (len < max_prefix)
 322                    max_prefix = len;
 323                for(j=0; j<max_prefix; j++) {
 324                    if (rs->completions[i][j] != rs->completions[0][j])
 325                        max_prefix = j;
 326                }
 327            }
 328            if (len > max_width)
 329                max_width = len;
 330        }
 331        if (max_prefix > 0) 
 332            for(i = rs->completion_index; i < max_prefix; i++) {
 333                readline_insert_char(rs, rs->completions[0][i]);
 334            }
 335        max_width += 2;
 336        if (max_width < 10)
 337            max_width = 10;
 338        else if (max_width > 80)
 339            max_width = 80;
 340        nb_cols = 80 / max_width;
 341        j = 0;
 342        for(i = 0; i < rs->nb_completions; i++) {
 343            rs->printf_func(rs->opaque, "%-*s", max_width, rs->completions[i]);
 344            if (++j == nb_cols || i == (rs->nb_completions - 1)) {
 345                rs->printf_func(rs->opaque, "\n");
 346                j = 0;
 347            }
 348        }
 349        readline_show_prompt(rs);
 350    }
 351    for (i = 0; i < rs->nb_completions; i++) {
 352        g_free(rs->completions[i]);
 353    }
 354}
 355
 356static void readline_clear_screen(ReadLineState *rs)
 357{
 358    rs->printf_func(rs->opaque, "\033[2J\033[1;1H");
 359    readline_show_prompt(rs);
 360}
 361
 362/* return true if command handled */
 363void readline_handle_byte(ReadLineState *rs, int ch)
 364{
 365    switch(rs->esc_state) {
 366    case IS_NORM:
 367        switch(ch) {
 368        case 1:
 369            readline_bol(rs);
 370            break;
 371        case 4:
 372            readline_delete_char(rs);
 373            break;
 374        case 5:
 375            readline_eol(rs);
 376            break;
 377        case 9:
 378            readline_completion(rs);
 379            break;
 380        case 12:
 381            readline_clear_screen(rs);
 382            break;
 383        case 10:
 384        case 13:
 385            rs->cmd_buf[rs->cmd_buf_size] = '\0';
 386            if (!rs->read_password)
 387                readline_hist_add(rs, rs->cmd_buf);
 388            rs->printf_func(rs->opaque, "\n");
 389            rs->cmd_buf_index = 0;
 390            rs->cmd_buf_size = 0;
 391            rs->last_cmd_buf_index = 0;
 392            rs->last_cmd_buf_size = 0;
 393            rs->readline_func(rs->opaque, rs->cmd_buf, rs->readline_opaque);
 394            break;
 395        case 23:
 396            /* ^W */
 397            readline_backword(rs);
 398            break;
 399        case 27:
 400            rs->esc_state = IS_ESC;
 401            break;
 402        case 127:
 403        case 8:
 404            readline_backspace(rs);
 405            break;
 406        case 155:
 407            rs->esc_state = IS_CSI;
 408            break;
 409        default:
 410            if (ch >= 32) {
 411                readline_insert_char(rs, ch);
 412            }
 413            break;
 414        }
 415        break;
 416    case IS_ESC:
 417        if (ch == '[') {
 418            rs->esc_state = IS_CSI;
 419            rs->esc_param = 0;
 420        } else if (ch == 'O') {
 421            rs->esc_state = IS_SS3;
 422            rs->esc_param = 0;
 423        } else {
 424            rs->esc_state = IS_NORM;
 425        }
 426        break;
 427    case IS_CSI:
 428        switch(ch) {
 429        case 'A':
 430        case 'F':
 431            readline_up_char(rs);
 432            break;
 433        case 'B':
 434        case 'E':
 435            readline_down_char(rs);
 436            break;
 437        case 'D':
 438            readline_backward_char(rs);
 439            break;
 440        case 'C':
 441            readline_forward_char(rs);
 442            break;
 443        case '0' ... '9':
 444            rs->esc_param = rs->esc_param * 10 + (ch - '0');
 445            goto the_end;
 446        case '~':
 447            switch(rs->esc_param) {
 448            case 1:
 449                readline_bol(rs);
 450                break;
 451            case 3:
 452                readline_delete_char(rs);
 453                break;
 454            case 4:
 455                readline_eol(rs);
 456                break;
 457            }
 458            break;
 459        default:
 460            break;
 461        }
 462        rs->esc_state = IS_NORM;
 463    the_end:
 464        break;
 465    case IS_SS3:
 466        switch(ch) {
 467        case 'F':
 468            readline_eol(rs);
 469            break;
 470        case 'H':
 471            readline_bol(rs);
 472            break;
 473        }
 474        rs->esc_state = IS_NORM;
 475        break;
 476    }
 477    readline_update(rs);
 478}
 479
 480void readline_start(ReadLineState *rs, const char *prompt, int read_password,
 481                    ReadLineFunc *readline_func, void *opaque)
 482{
 483    pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
 484    rs->readline_func = readline_func;
 485    rs->readline_opaque = opaque;
 486    rs->read_password = read_password;
 487    readline_restart(rs);
 488}
 489
 490void readline_restart(ReadLineState *rs)
 491{
 492    rs->cmd_buf_index = 0;
 493    rs->cmd_buf_size = 0;
 494}
 495
 496const char *readline_get_history(ReadLineState *rs, unsigned int index)
 497{
 498    if (index >= READLINE_MAX_CMDS)
 499        return NULL;
 500    return rs->history[index];
 501}
 502
 503ReadLineState *readline_init(ReadLinePrintfFunc *printf_func,
 504                             ReadLineFlushFunc *flush_func,
 505                             void *opaque,
 506                             ReadLineCompletionFunc *completion_finder)
 507{
 508    ReadLineState *rs = g_malloc0(sizeof(*rs));
 509
 510    rs->hist_entry = -1;
 511    rs->opaque = opaque;
 512    rs->printf_func = printf_func;
 513    rs->flush_func = flush_func;
 514    rs->completion_finder = completion_finder;
 515
 516    return rs;
 517}
 518