libbb/lineedit.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Command line editing.
   4  *
   5  * Copyright (c) 1986-2003 may safely be consumed by a BSD or GPL license.
   6  * Written by:   Vladimir Oleynik <dzo@simtreas.ru>
   7  *
   8  * Used ideas:
   9  *      Adam Rogoyski    <rogoyski@cs.utexas.edu>
  10  *      Dave Cinege      <dcinege@psychosis.com>
  11  *      Jakub Jelinek (c) 1995
  12  *      Erik Andersen    <andersen@codepoet.org> (Majorly adjusted for busybox)
  13  *
  14  * This code is 'as is' with no warranty.
  15  */
  16
  17 /*
  18  * Usage and known bugs:
  19  * Terminal key codes are not extensive, more needs to be added.
  20  * This version was created on Debian GNU/Linux 2.x.
  21  * Delete, Backspace, Home, End, and the arrow keys were tested
  22  * to work in an Xterm and console. Ctrl-A also works as Home.
  23  * Ctrl-E also works as End.
  24  *
  25  * The following readline-like commands are not implemented:
  26  * ESC-b -- Move back one word
  27  * ESC-f -- Move forward one word
  28  * ESC-d -- Delete forward one word
  29  * CTL-t -- Transpose two characters
  30  *
  31  * lineedit does not know that the terminal escape sequences do not
  32  * take up space on the screen. The redisplay code assumes, unless
  33  * told otherwise, that each character in the prompt is a printable
  34  * character that takes up one character position on the screen.
  35  * You need to tell lineedit that some sequences of characters
  36  * in the prompt take up no screen space. Compatibly with readline,
  37  * use the \[ escape to begin a sequence of non-printing characters,
  38  * and the \] escape to signal the end of such a sequence. Example:
  39  *
  40  * PS1='\[\033[01;32m\]\u@\h\[\033[01;34m\] \w \$\[\033[00m\] '
  41  */
  42 #include "libbb.h"
  43 #include "unicode.h"
  44
  45 #ifdef TEST
  46 # define ENABLE_FEATURE_EDITING 0
  47 # define ENABLE_FEATURE_TAB_COMPLETION 0
  48 # define ENABLE_FEATURE_USERNAME_COMPLETION 0
  49 #endif
  50
  51
  52 /* Entire file (except TESTing part) sits inside this #if */
  53 #if ENABLE_FEATURE_EDITING
  54
  55
  56 #define ENABLE_USERNAME_OR_HOMEDIR \
  57         (ENABLE_FEATURE_USERNAME_COMPLETION || ENABLE_FEATURE_EDITING_FANCY_PROMPT)
  58 #define IF_USERNAME_OR_HOMEDIR(...)
  59 #if ENABLE_USERNAME_OR_HOMEDIR
  60 # undef IF_USERNAME_OR_HOMEDIR
  61 # define IF_USERNAME_OR_HOMEDIR(...) __VA_ARGS__
  62 #endif
  63
  64
  65 #undef CHAR_T
  66 #if ENABLE_UNICODE_SUPPORT
  67 # define BB_NUL ((wchar_t)0)
  68 # define CHAR_T wchar_t
  69 static bool BB_isspace(CHAR_T c) { return ((unsigned)c < 256 && isspace(c)); }
  70 # if ENABLE_FEATURE_EDITING_VI
  71 static bool BB_isalnum(CHAR_T c) { return ((unsigned)c < 256 && isalnum(c)); }
  72 # endif
  73 static bool BB_ispunct(CHAR_T c) { return ((unsigned)c < 256 && ispunct(c)); }
  74 # undef isspace
  75 # undef isalnum
  76 # undef ispunct
  77 # undef isprint
  78 # define isspace isspace_must_not_be_used
  79 # define isalnum isalnum_must_not_be_used
  80 # define ispunct ispunct_must_not_be_used
  81 # define isprint isprint_must_not_be_used
  82 #else
  83 # define BB_NUL '\0'
  84 # define CHAR_T char
  85 # define BB_isspace(c) isspace(c)
  86 # define BB_isalnum(c) isalnum(c)
  87 # define BB_ispunct(c) ispunct(c)
  88 #endif
  89 #if ENABLE_UNICODE_PRESERVE_BROKEN
  90 # define unicode_mark_raw_byte(wc)   ((wc) | 0x20000000)
  91 # define unicode_is_raw_byte(wc)     ((wc) & 0x20000000)
  92 #else
  93 # define unicode_is_raw_byte(wc)     0
  94 #endif
  95
  96
  97 #define ESC "\033"
  98
  99 #define SEQ_CLEAR_TILL_END_OF_SCREEN  ESC"[J"
 100 //#define SEQ_CLEAR_TILL_END_OF_LINE  ESC"[K"
 101
 102
 103 enum {
 104         MAX_LINELEN = CONFIG_FEATURE_EDITING_MAX_LEN < 0x7ff0
 105                       ? CONFIG_FEATURE_EDITING_MAX_LEN
 106                       : 0x7ff0
 107 };
 108
 109 #if ENABLE_USERNAME_OR_HOMEDIR
 110 static const char null_str[] ALIGN1 = "";
 111 #endif
 112
 113 /* We try to minimize both static and stack usage. */
 114 struct lineedit_statics {
 115         line_input_t *state;
 116
 117         volatile unsigned cmdedit_termw; /* = 80; */ /* actual terminal width */
 118         sighandler_t previous_SIGWINCH_handler;
 119
 120         unsigned cmdedit_x;        /* real x (col) terminal position */
 121         unsigned cmdedit_y;        /* pseudoreal y (row) terminal position */
 122         unsigned cmdedit_prmt_len; /* length of prompt (without colors etc) */
 123
 124         unsigned cursor;
 125         int command_len; /* must be signed */
 126         /* signed maxsize: we want x in "if (x > S.maxsize)"
 127          * to _not_ be promoted to unsigned */
 128         int maxsize;
 129         CHAR_T *command_ps;
 130
 131         const char *cmdedit_prompt;
 132 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
 133         int num_ok_lines; /* = 1; */
 134 #endif
 135
 136 #if ENABLE_USERNAME_OR_HOMEDIR
 137         char *user_buf;
 138         char *home_pwd_buf; /* = (char*)null_str; */
 139 #endif
 140
 141 #if ENABLE_FEATURE_TAB_COMPLETION
 142         char **matches;
 143         unsigned num_matches;
 144 #endif
 145
 146 #if ENABLE_FEATURE_EDITING_VI
 147 # define DELBUFSIZ 128
 148         CHAR_T *delptr;
 149         smallint newdelflag;     /* whether delbuf should be reused yet */
 150         CHAR_T delbuf[DELBUFSIZ];  /* a place to store deleted characters */
 151 #endif
 152 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
 153         smallint sent_ESC_br6n;
 154 #endif
 155 };
 156
 157 /* See lineedit_ptr_hack.c */
 158 extern struct lineedit_statics *const lineedit_ptr_to_statics;
 159
 160 #define S (*lineedit_ptr_to_statics)
 161 #define state            (S.state           )
 162 #define cmdedit_termw    (S.cmdedit_termw   )
 163 #define previous_SIGWINCH_handler (S.previous_SIGWINCH_handler)
 164 #define cmdedit_x        (S.cmdedit_x       )
 165 #define cmdedit_y        (S.cmdedit_y       )
 166 #define cmdedit_prmt_len (S.cmdedit_prmt_len)
 167 #define cursor           (S.cursor          )
 168 #define command_len      (S.command_len     )
 169 #define command_ps       (S.command_ps      )
 170 #define cmdedit_prompt   (S.cmdedit_prompt  )
 171 #define num_ok_lines     (S.num_ok_lines    )
 172 #define user_buf         (S.user_buf        )
 173 #define home_pwd_buf     (S.home_pwd_buf    )
 174 #define matches          (S.matches         )
 175 #define num_matches      (S.num_matches     )
 176 #define delptr           (S.delptr          )
 177 #define newdelflag       (S.newdelflag      )
 178 #define delbuf           (S.delbuf          )
 179
 180 #define INIT_S() do { \
 181         (*(struct lineedit_statics**)&lineedit_ptr_to_statics) = xzalloc(sizeof(S)); \
 182         barrier(); \
 183         cmdedit_termw = 80; \
 184         IF_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines = 1;) \
 185         IF_USERNAME_OR_HOMEDIR(home_pwd_buf = (char*)null_str;) \
 186 } while (0)
 187 static void deinit_S(void)
 188 {
 189 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
 190         /* This one is allocated only if FANCY_PROMPT is on
 191          * (otherwise it points to verbatim prompt (NOT malloced)) */
 192         free((char*)cmdedit_prompt);
 193 #endif
 194 #if ENABLE_USERNAME_OR_HOMEDIR
 195         free(user_buf);
 196         if (home_pwd_buf != null_str)
 197                 free(home_pwd_buf);
 198 #endif
 199         free(lineedit_ptr_to_statics);
 200 }
 201 #define DEINIT_S() deinit_S()
 202
 203
 204 #if ENABLE_UNICODE_SUPPORT
 205 static size_t load_string(const char *src, int maxsize)
 206 {
 207         ssize_t len = mbstowcs(command_ps, src, maxsize - 1);
 208         if (len < 0)
 209                 len = 0;
 210         command_ps[len] = BB_NUL;
 211         return len;
 212 }
 213 static unsigned save_string(char *dst, unsigned maxsize)
 214 {
 215 # if !ENABLE_UNICODE_PRESERVE_BROKEN
 216         ssize_t len = wcstombs(dst, command_ps, maxsize - 1);
 217         if (len < 0)
 218                 len = 0;
 219         dst[len] = '\0';
 220         return len;
 221 # else
 222         unsigned dstpos = 0;
 223         unsigned srcpos = 0;
 224
 225         maxsize--;
 226         while (dstpos < maxsize) {
 227                 wchar_t wc;
 228                 int n = srcpos;
 229
 230                 /* Convert up to 1st invalid byte (or up to end) */
 231                 while ((wc = command_ps[srcpos]) != BB_NUL
 232                     && !unicode_is_raw_byte(wc)
 233                 ) {
 234                         srcpos++;
 235                 }
 236                 command_ps[srcpos] = BB_NUL;
 237                 n = wcstombs(dst + dstpos, command_ps + n, maxsize - dstpos);
 238                 if (n < 0) /* should not happen */
 239                         break;
 240                 dstpos += n;
 241                 if (wc == BB_NUL) /* usually is */
 242                         break;
 243
 244                 /* We do have invalid byte here! */
 245                 command_ps[srcpos] = wc; /* restore it */
 246                 srcpos++;
 247                 if (dstpos == maxsize)
 248                         break;
 249                 dst[dstpos++] = (char) wc;
 250         }
 251         dst[dstpos] = '\0';
 252         return dstpos;
 253 # endif
 254 }
 255 /* I thought just fputwc(c, stdout) would work. But no... */
 256 static void BB_PUTCHAR(wchar_t c)
 257 {
 258         char buf[MB_CUR_MAX + 1];
 259         mbstate_t mbst = { 0 };
 260         ssize_t len;
 261
 262         len = wcrtomb(buf, c, &mbst);
 263         if (len > 0) {
 264                 buf[len] = '\0';
 265                 fputs(buf, stdout);
 266         }
 267 }
 268 # if ENABLE_UNICODE_COMBINING_WCHARS || ENABLE_UNICODE_WIDE_WCHARS
 269 static wchar_t adjust_width_and_validate_wc(unsigned *width_adj, wchar_t wc)
 270 # else
 271 static wchar_t adjust_width_and_validate_wc(wchar_t wc)
 272 #  define adjust_width_and_validate_wc(width_adj, wc) \
 273         ((*(width_adj))++, adjust_width_and_validate_wc(wc))
 274 # endif
 275 {
 276         int w = 1;
 277
 278         if (unicode_status == UNICODE_ON) {
 279                 if (wc > CONFIG_LAST_SUPPORTED_WCHAR) {
 280                         /* note: also true for unicode_is_raw_byte(wc) */
 281                         goto subst;
 282                 }
 283                 w = wcwidth(wc);
 284                 if ((ENABLE_UNICODE_COMBINING_WCHARS && w < 0)
 285                  || (!ENABLE_UNICODE_COMBINING_WCHARS && w <= 0)
 286                  || (!ENABLE_UNICODE_WIDE_WCHARS && w > 1)
 287                 ) {
 288  subst:
 289                         w = 1;
 290                         wc = CONFIG_SUBST_WCHAR;
 291                 }
 292         }
 293
 294 # if ENABLE_UNICODE_COMBINING_WCHARS || ENABLE_UNICODE_WIDE_WCHARS
 295         *width_adj += w;
 296 #endif
 297         return wc;
 298 }
 299 #else /* !UNICODE */
 300 static size_t load_string(const char *src, int maxsize)
 301 {
 302         safe_strncpy(command_ps, src, maxsize);
 303         return strlen(command_ps);
 304 }
 305 # if ENABLE_FEATURE_TAB_COMPLETION
 306 static void save_string(char *dst, unsigned maxsize)
 307 {
 308         safe_strncpy(dst, command_ps, maxsize);
 309 }
 310 # endif
 311 # define BB_PUTCHAR(c) bb_putchar(c)
 312 /* Should never be called: */
 313 int adjust_width_and_validate_wc(unsigned *width_adj, int wc);
 314 #endif
 315
 316
 317 /* Put 'command_ps[cursor]', cursor++.
 318  * Advance cursor on screen. If we reached right margin, scroll text up
 319  * and remove terminal margin effect by printing 'next_char' */
 320 #define HACK_FOR_WRONG_WIDTH 1
 321 static void put_cur_glyph_and_inc_cursor(void)
 322 {
 323         CHAR_T c = command_ps[cursor];
 324         unsigned width = 0;
 325         int ofs_to_right;
 326
 327         if (c == BB_NUL) {
 328                 /* erase character after end of input string */
 329                 c = ' ';
 330         } else {
 331                 /* advance cursor only if we aren't at the end yet */
 332                 cursor++;
 333                 if (unicode_status == UNICODE_ON) {
 334                         IF_UNICODE_WIDE_WCHARS(width = cmdedit_x;)
 335                         c = adjust_width_and_validate_wc(&cmdedit_x, c);
 336                         IF_UNICODE_WIDE_WCHARS(width = cmdedit_x - width;)
 337                 } else {
 338                         cmdedit_x++;
 339                 }
 340         }
 341
 342         ofs_to_right = cmdedit_x - cmdedit_termw;
 343         if (!ENABLE_UNICODE_WIDE_WCHARS || ofs_to_right <= 0) {
 344                 /* c fits on this line */
 345                 BB_PUTCHAR(c);
 346         }
 347
 348         if (ofs_to_right >= 0) {
 349                 /* we go to the next line */
 350 #if HACK_FOR_WRONG_WIDTH
 351                 /* This works better if our idea of term width is wrong
 352                  * and it is actually wider (often happens on serial lines).
 353                  * Printing CR,LF *forces* cursor to next line.
 354                  * OTOH if terminal width is correct AND terminal does NOT
 355                  * have automargin (IOW: it is moving cursor to next line
 356                  * by itself (which is wrong for VT-10x terminals)),
 357                  * this will break things: there will be one extra empty line */
 358                 puts("\r"); /* + implicit '\n' */
 359 #else
 360                 /* VT-10x terminals don't wrap cursor to next line when last char
 361                  * on the line is printed - cursor stays "over" this char.
 362                  * Need to print _next_ char too (first one to appear on next line)
 363                  * to make cursor move down to next line.
 364                  */
 365                 /* Works ok only if cmdedit_termw is correct. */
 366                 c = command_ps[cursor];
 367                 if (c == BB_NUL)
 368                         c = ' ';
 369                 BB_PUTCHAR(c);
 370                 bb_putchar('\b');
 371 #endif
 372                 cmdedit_y++;
 373                 if (!ENABLE_UNICODE_WIDE_WCHARS || ofs_to_right == 0) {
 374                         width = 0;
 375                 } else { /* ofs_to_right > 0 */
 376                         /* wide char c didn't fit on prev line */
 377                         BB_PUTCHAR(c);
 378                 }
 379                 cmdedit_x = width;
 380         }
 381 }
 382
 383 /* Move to end of line (by printing all chars till the end) */
 384 static void put_till_end_and_adv_cursor(void)
 385 {
 386         while (cursor < command_len)
 387                 put_cur_glyph_and_inc_cursor();
 388 }
 389
 390 /* Go to the next line */
 391 static void goto_new_line(void)
 392 {
 393         put_till_end_and_adv_cursor();
 394         if (cmdedit_x != 0)
 395                 bb_putchar('\n');
 396 }
 397
 398 static void beep(void)
 399 {
 400         bb_putchar('\007');
 401 }
 402
 403 static void put_prompt(void)
 404 {
 405         unsigned w;
 406
 407         fputs(cmdedit_prompt, stdout);
 408         fflush_all();
 409         cursor = 0;
 410         w = cmdedit_termw; /* read volatile var once */
 411         cmdedit_y = cmdedit_prmt_len / w; /* new quasireal y */
 412         cmdedit_x = cmdedit_prmt_len % w;
 413 }
 414
 415 /* Move back one character */
 416 /* (optimized for slow terminals) */
 417 static void input_backward(unsigned num)
 418 {
 419         if (num > cursor)
 420                 num = cursor;
 421         if (num == 0)
 422                 return;
 423         cursor -= num;
 424
 425         if ((ENABLE_UNICODE_COMBINING_WCHARS || ENABLE_UNICODE_WIDE_WCHARS)
 426          && unicode_status == UNICODE_ON
 427         ) {
 428                 /* correct NUM to be equal to _screen_ width */
 429                 int n = num;
 430                 num = 0;
 431                 while (--n >= 0)
 432                         adjust_width_and_validate_wc(&num, command_ps[cursor + n]);
 433                 if (num == 0)
 434                         return;
 435         }
 436
 437         if (cmdedit_x >= num) {
 438                 cmdedit_x -= num;
 439                 if (num <= 4) {
 440                         /* This is longer by 5 bytes on x86.
 441                          * Also gets miscompiled for ARM users
 442                          * (busybox.net/bugs/view.php?id=2274).
 443                          * printf(("\b\b\b\b" + 4) - num);
 444                          * return;
 445                          */
 446                         do {
 447                                 bb_putchar('\b');
 448                         } while (--num);
 449                         return;
 450                 }
 451                 printf(ESC"[%uD", num);
 452                 return;
 453         }
 454
 455         /* Need to go one or more lines up */
 456         if (ENABLE_UNICODE_WIDE_WCHARS) {
 457                 /* With wide chars, it is hard to "backtrack"
 458                  * and reliably figure out where to put cursor.
 459                  * Example (<> is a wide char; # is an ordinary char, _ cursor):
 460                  * |prompt: <><> |
 461                  * |<><><><><><> |
 462                  * |_            |
 463                  * and user presses left arrow. num = 1, cmdedit_x = 0,
 464                  * We need to go up one line, and then - how do we know that
 465                  * we need to go *10* positions to the right? Because
 466                  * |prompt: <>#<>|
 467                  * |<><><>#<><><>|
 468                  * |_            |
 469                  * in this situation we need to go *11* positions to the right.
 470                  *
 471                  * A simpler thing to do is to redraw everything from the start
 472                  * up to new cursor position (which is already known):
 473                  */
 474                 unsigned sv_cursor;
 475                 /* go to 1st column; go up to first line */
 476                 printf("\r" ESC"[%uA", cmdedit_y);
 477                 cmdedit_y = 0;
 478                 sv_cursor = cursor;
 479                 put_prompt(); /* sets cursor to 0 */
 480                 while (cursor < sv_cursor)
 481                         put_cur_glyph_and_inc_cursor();
 482         } else {
 483                 int lines_up;
 484                 unsigned width;
 485                 /* num = chars to go back from the beginning of current line: */
 486                 num -= cmdedit_x;
 487                 width = cmdedit_termw; /* read volatile var once */
 488                 /* num=1...w: one line up, w+1...2w: two, etc: */
 489                 lines_up = 1 + (num - 1) / width;
 490                 cmdedit_x = (width * cmdedit_y - num) % width;
 491                 cmdedit_y -= lines_up;
 492                 /* go to 1st column; go up */
 493                 printf("\r" ESC"[%uA", lines_up);
 494                 /* go to correct column.
 495                  * xterm, konsole, Linux VT interpret 0 as 1 below! wow.
 496                  * need to *make sure* we skip it if cmdedit_x == 0 */
 497                 if (cmdedit_x)
 498                         printf(ESC"[%uC", cmdedit_x);
 499         }
 500 }
 501
 502 /* draw prompt, editor line, and clear tail */
 503 static void redraw(int y, int back_cursor)
 504 {
 505         if (y > 0) /* up y lines */
 506                 printf(ESC"[%uA", y);
 507         bb_putchar('\r');
 508         put_prompt();
 509         put_till_end_and_adv_cursor();
 510         printf(SEQ_CLEAR_TILL_END_OF_SCREEN);
 511         input_backward(back_cursor);
 512 }
 513
 514 /* Delete the char in front of the cursor, optionally saving it
 515  * for later putback */
 516 #if !ENABLE_FEATURE_EDITING_VI
 517 static void input_delete(void)
 518 #define input_delete(save) input_delete()
 519 #else
 520 static void input_delete(int save)
 521 #endif
 522 {
 523         int j = cursor;
 524
 525         if (j == (int)command_len)
 526                 return;
 527
 528 #if ENABLE_FEATURE_EDITING_VI
 529         if (save) {
 530                 if (newdelflag) {
 531                         delptr = delbuf;
 532                         newdelflag = 0;
 533                 }
 534                 if ((delptr - delbuf) < DELBUFSIZ)
 535                         *delptr++ = command_ps[j];
 536         }
 537 #endif
 538
 539         memmove(command_ps + j, command_ps + j + 1,
 540                         /* (command_len + 1 [because of NUL]) - (j + 1)
 541                          * simplified into (command_len - j) */
 542                         (command_len - j) * sizeof(command_ps[0]));
 543         command_len--;
 544         put_till_end_and_adv_cursor();
 545         /* Last char is still visible, erase it (and more) */
 546         printf(SEQ_CLEAR_TILL_END_OF_SCREEN);
 547         input_backward(cursor - j);     /* back to old pos cursor */
 548 }
 549
 550 #if ENABLE_FEATURE_EDITING_VI
 551 static void put(void)
 552 {
 553         int ocursor;
 554         int j = delptr - delbuf;
 555
 556         if (j == 0)
 557                 return;
 558         ocursor = cursor;
 559         /* open hole and then fill it */
 560         memmove(command_ps + cursor + j, command_ps + cursor,
 561                         (command_len - cursor + 1) * sizeof(command_ps[0]));
 562         memcpy(command_ps + cursor, delbuf, j * sizeof(command_ps[0]));
 563         command_len += j;
 564         put_till_end_and_adv_cursor();
 565         input_backward(cursor - ocursor - j + 1); /* at end of new text */
 566 }
 567 #endif
 568
 569 /* Delete the char in back of the cursor */
 570 static void input_backspace(void)
 571 {
 572         if (cursor > 0) {
 573                 input_backward(1);
 574                 input_delete(0);
 575         }
 576 }
 577
 578 /* Move forward one character */
 579 static void input_forward(void)
 580 {
 581         if (cursor < command_len)
 582                 put_cur_glyph_and_inc_cursor();
 583 }
 584
 585 #if ENABLE_FEATURE_TAB_COMPLETION
 586
 587 //FIXME:
 588 //needs to be more clever: currently it thinks that "foo\ b<TAB>
 589 //matches the file named "foo bar", which is untrue.
 590 //Also, perhaps "foo b<TAB> needs to complete to "foo bar" <cursor>,
 591 //not "foo bar <cursor>...
 592
 593 static void free_tab_completion_data(void)
 594 {
 595         if (matches) {
 596                 while (num_matches)
 597                         free(matches[--num_matches]);
 598                 free(matches);
 599                 matches = NULL;
 600         }
 601 }
 602
 603 static void add_match(char *matched)
 604 {
 605         matches = xrealloc_vector(matches, 4, num_matches);
 606         matches[num_matches] = matched;
 607         num_matches++;
 608 }
 609
 610 # if ENABLE_FEATURE_USERNAME_COMPLETION
 611 /* Replace "~user/..." with "/homedir/...".
 612  * The parameter is malloced, free it or return it
 613  * unchanged if no user is matched.
 614  */
 615 static char *username_path_completion(char *ud)
 616 {
 617         struct passwd *entry;
 618         char *tilde_name = ud;
 619         char *home = NULL;
 620
 621         ud++; /* skip ~ */
 622         if (*ud == '/') {       /* "~/..." */
 623                 home = home_pwd_buf;
 624         } else {
 625                 /* "~user/..." */
 626                 ud = strchr(ud, '/');
 627                 *ud = '\0';           /* "~user" */
 628                 entry = getpwnam(tilde_name + 1);
 629                 *ud = '/';            /* restore "~user/..." */
 630                 if (entry)
 631                         home = entry->pw_dir;
 632         }
 633         if (home) {
 634                 ud = concat_path_file(home, ud);
 635                 free(tilde_name);
 636                 tilde_name = ud;
 637         }
 638         return tilde_name;
 639 }
 640
 641 /* ~use<tab> - find all users with this prefix.
 642  * Return the length of the prefix used for matching.
 643  */
 644 static NOINLINE unsigned complete_username(const char *ud)
 645 {
 646         /* Using _r function to avoid pulling in static buffers */
 647         char line_buff[256];
 648         struct passwd pwd;
 649         struct passwd *result;
 650         unsigned userlen;
 651
 652         ud++; /* skip ~ */
 653         userlen = strlen(ud);
 654
 655         setpwent();
 656         while (!getpwent_r(&pwd, line_buff, sizeof(line_buff), &result)) {
 657                 /* Null usernames should result in all users as possible completions. */
 658                 if (/*!userlen || */ strncmp(ud, pwd.pw_name, userlen) == 0) {
 659                         add_match(xasprintf("~%s/", pwd.pw_name));
 660                 }
 661         }
 662         endpwent();
 663
 664         return 1 + userlen;
 665 }
 666 # endif  /* FEATURE_USERNAME_COMPLETION */
 667
 668 enum {
 669         FIND_EXE_ONLY = 0,
 670         FIND_DIR_ONLY = 1,
 671         FIND_FILE_ONLY = 2,
 672 };
 673
 674 static int path_parse(char ***p)
 675 {
 676         int npth;
 677         const char *pth;
 678         char *tmp;
 679         char **res;
 680
 681         if (state->flags & WITH_PATH_LOOKUP)
 682                 pth = state->path_lookup;
 683         else
 684                 pth = getenv("PATH");
 685
 686         /* PATH="" or PATH=":"? */
 687         if (!pth || !pth[0] || LONE_CHAR(pth, ':'))
 688                 return 1;
 689
 690         tmp = (char*)pth;
 691         npth = 1; /* path component count */
 692         while (1) {
 693                 tmp = strchr(tmp, ':');
 694                 if (!tmp)
 695                         break;
 696                 tmp++;
 697                 if (*tmp == '\0')
 698                         break;  /* :<empty> */
 699                 npth++;
 700         }
 701
 702         *p = res = xmalloc(npth * sizeof(res[0]));
 703         res[0] = tmp = xstrdup(pth);
 704         npth = 1;
 705         while (1) {
 706                 tmp = strchr(tmp, ':');
 707                 if (!tmp)
 708                         break;
 709                 *tmp++ = '\0'; /* ':' -> '\0' */
 710                 if (*tmp == '\0')
 711                         break; /* :<empty> */
 712                 res[npth++] = tmp;
 713         }
 714         return npth;
 715 }
 716
 717 /* Complete command, directory or file name.
 718  * Return the length of the prefix used for matching.
 719  */
 720 static NOINLINE unsigned complete_cmd_dir_file(const char *command, int type)
 721 {
 722         char *path1[1];
 723         char **paths = path1;
 724         int npaths;
 725         int i;
 726         unsigned pf_len;
 727         const char *pfind;
 728         char *dirbuf = NULL;
 729
 730         npaths = 1;
 731         path1[0] = (char*)".";
 732
 733         pfind = strrchr(command, '/');
 734         if (!pfind) {
 735                 if (type == FIND_EXE_ONLY)
 736                         npaths = path_parse(&paths);
 737                 pfind = command;
 738         } else {
 739                 /* point to 'l' in "..../last_component" */
 740                 pfind++;
 741                 /* dirbuf = ".../.../.../" */
 742                 dirbuf = xstrndup(command, pfind - command);
 743 # if ENABLE_FEATURE_USERNAME_COMPLETION
 744                 if (dirbuf[0] == '~')   /* ~/... or ~user/... */
 745                         dirbuf = username_path_completion(dirbuf);
 746 # endif
 747                 path1[0] = dirbuf;
 748         }
 749         pf_len = strlen(pfind);
 750
 751         for (i = 0; i < npaths; i++) {
 752                 DIR *dir;
 753                 struct dirent *next;
 754                 struct stat st;
 755                 char *found;
 756
 757                 dir = opendir(paths[i]);
 758                 if (!dir)
 759                         continue; /* don't print an error */
 760
 761                 while ((next = readdir(dir)) != NULL) {
 762                         unsigned len;
 763                         const char *name_found = next->d_name;
 764
 765                         /* .../<tab>: bash 3.2.0 shows dotfiles, but not . and .. */
 766                         if (!pfind[0] && DOT_OR_DOTDOT(name_found))
 767                                 continue;
 768                         /* match? */
 769                         if (strncmp(name_found, pfind, pf_len) != 0)
 770                                 continue; /* no */
 771
 772                         found = concat_path_file(paths[i], name_found);
 773                         /* NB: stat() first so that we see is it a directory;
 774                          * but if that fails, use lstat() so that
 775                          * we still match dangling links */
 776                         if (stat(found, &st) && lstat(found, &st))
 777                                 goto cont; /* hmm, remove in progress? */
 778
 779                         /* Save only name */
 780                         len = strlen(name_found);
 781                         found = xrealloc(found, len + 2); /* +2: for slash and NUL */
 782                         strcpy(found, name_found);
 783
 784                         if (S_ISDIR(st.st_mode)) {
 785                                 /* name is a directory, add slash */
 786                                 found[len] = '/';
 787                                 found[len + 1] = '\0';
 788                         } else {
 789                                 /* skip files if looking for dirs only (example: cd) */
 790                                 if (type == FIND_DIR_ONLY)
 791                                         goto cont;
 792                         }
 793                         /* add it to the list */
 794                         add_match(found);
 795                         continue;
 796  cont:
 797                         free(found);
 798                 }
 799                 closedir(dir);
 800         } /* for every path */
 801
 802         if (paths != path1) {
 803                 free(paths[0]); /* allocated memory is only in first member */
 804                 free(paths);
 805         }
 806         free(dirbuf);
 807
 808         return pf_len;
 809 }
 810
 811 /* build_match_prefix:
 812  * On entry, match_buf contains everything up to cursor at the moment <tab>
 813  * was pressed. This function looks at it, figures out what part of it
 814  * constitutes the command/file/directory prefix to use for completion,
 815  * and rewrites match_buf to contain only that part.
 816  */
 817 #define dbg_bmp 0
 818 /* Helpers: */
 819 /* QUOT is used on elements of int_buf[], which are bytes,
 820  * not Unicode chars. Therefore it works correctly even in Unicode mode.
 821  */
 822 #define QUOT (UCHAR_MAX+1)
 823 static void remove_chunk(int16_t *int_buf, int beg, int end)
 824 {
 825         /* beg must be <= end */
 826         if (beg == end)
 827                 return;
 828
 829         while ((int_buf[beg] = int_buf[end]) != 0)
 830                 beg++, end++;
 831
 832         if (dbg_bmp) {
 833                 int i;
 834                 for (i = 0; int_buf[i]; i++)
 835                         bb_putchar((unsigned char)int_buf[i]);
 836                 bb_putchar('\n');
 837         }
 838 }
 839 /* Caller ensures that match_buf points to a malloced buffer
 840  * big enough to hold strlen(match_buf)*2 + 2
 841  */
 842 static NOINLINE int build_match_prefix(char *match_buf)
 843 {
 844         int i, j;
 845         int command_mode;
 846         int16_t *int_buf = (int16_t*)match_buf;
 847
 848         if (dbg_bmp) printf("\n%s\n", match_buf);
 849
 850         /* Copy in reverse order, since they overlap */
 851         i = strlen(match_buf);
 852         do {
 853                 int_buf[i] = (unsigned char)match_buf[i];
 854                 i--;
 855         } while (i >= 0);
 856
 857         /* Mark every \c as "quoted c" */
 858         for (i = 0; int_buf[i]; i++) {
 859                 if (int_buf[i] == '\\') {
 860                         remove_chunk(int_buf, i, i + 1);
 861                         int_buf[i] |= QUOT;
 862                 }
 863         }
 864         /* Quote-mark "chars" and 'chars', drop delimiters */
 865         {
 866                 int in_quote = 0;
 867                 i = 0;
 868                 while (int_buf[i]) {
 869                         int cur = int_buf[i];
 870                         if (!cur)
 871                                 break;
 872                         if (cur == '\'' || cur == '"') {
 873                                 if (!in_quote || (cur == in_quote)) {
 874                                         in_quote ^= cur;
 875                                         remove_chunk(int_buf, i, i + 1);
 876                                         continue;
 877                                 }
 878                         }
 879                         if (in_quote)
 880                                 int_buf[i] = cur | QUOT;
 881                         i++;
 882                 }
 883         }
 884
 885         /* Remove everything up to command delimiters:
 886          * ';' ';;' '&' '|' '&&' '||',
 887          * but careful with '>&' '<&' '>|'
 888          */
 889         for (i = 0; int_buf[i]; i++) {
 890                 int cur = int_buf[i];
 891                 if (cur == ';' || cur == '&' || cur == '|') {
 892                         int prev = i ? int_buf[i - 1] : 0;
 893                         if (cur == '&' && (prev == '>' || prev == '<')) {
 894                                 continue;
 895                         } else if (cur == '|' && prev == '>') {
 896                                 continue;
 897                         }
 898                         remove_chunk(int_buf, 0, i + 1 + (cur == int_buf[i + 1]));
 899                         i = -1;  /* back to square 1 */
 900                 }
 901         }
 902         /* Remove all `cmd` */
 903         for (i = 0; int_buf[i]; i++) {
 904                 if (int_buf[i] == '`') {
 905                         for (j = i + 1; int_buf[j]; j++) {
 906                                 if (int_buf[j] == '`') {
 907                                         /* `cmd` should count as a word:
 908                                          * `cmd` c<tab> should search for files c*,
 909                                          * not commands c*. Therefore we don't drop
 910                                          * `cmd` entirely, we replace it with single `.
 911                                          */
 912                                         remove_chunk(int_buf, i, j);
 913                                         goto next;
 914                                 }
 915                         }
 916                         /* No closing ` - command mode, remove all up to ` */
 917                         remove_chunk(int_buf, 0, i + 1);
 918                         break;
 919  next: ;
 920                 }
 921         }
 922
 923         /* Remove "cmd (" and "cmd {"
 924          * Example: "if { c<tab>"
 925          * In this example, c should be matched as command pfx.
 926          */
 927         for (i = 0; int_buf[i]; i++) {
 928                 if (int_buf[i] == '(' || int_buf[i] == '{') {
 929                         remove_chunk(int_buf, 0, i + 1);
 930                         i = -1;  /* back to square 1 */
 931                 }
 932         }
 933
 934         /* Remove leading unquoted spaces */
 935         for (i = 0; int_buf[i]; i++)
 936                 if (int_buf[i] != ' ')
 937                         break;
 938         remove_chunk(int_buf, 0, i);
 939
 940         /* Determine completion mode */
 941         command_mode = FIND_EXE_ONLY;
 942         for (i = 0; int_buf[i]; i++) {
 943                 if (int_buf[i] == ' ' || int_buf[i] == '<' || int_buf[i] == '>') {
 944                         if (int_buf[i] == ' '
 945                          && command_mode == FIND_EXE_ONLY
 946                          && (char)int_buf[0] == 'c'
 947                          && (char)int_buf[1] == 'd'
 948                          && i == 2 /* -> int_buf[2] == ' ' */
 949                         ) {
 950                                 command_mode = FIND_DIR_ONLY;
 951                         } else {
 952                                 command_mode = FIND_FILE_ONLY;
 953                                 break;
 954                         }
 955                 }
 956         }
 957         if (dbg_bmp) printf("command_mode(0:exe/1:dir/2:file):%d\n", command_mode);
 958
 959         /* Remove everything except last word */
 960         for (i = 0; int_buf[i]; i++) /* quasi-strlen(int_buf) */
 961                 continue;
 962         for (--i; i >= 0; i--) {
 963                 int cur = int_buf[i];
 964                 if (cur == ' ' || cur == '<' || cur == '>' || cur == '|' || cur == '&') {
 965                         remove_chunk(int_buf, 0, i + 1);
 966                         break;
 967                 }
 968         }
 969
 970         /* Convert back to string of _chars_ */
 971         i = 0;
 972         while ((match_buf[i] = int_buf[i]) != '\0')
 973                 i++;
 974
 975         if (dbg_bmp) printf("final match_buf:'%s'\n", match_buf);
 976
 977         return command_mode;
 978 }
 979
 980 /*
 981  * Display by column (original idea from ls applet,
 982  * very optimized by me [Vladimir] :)
 983  */
 984 static void showfiles(void)
 985 {
 986         int ncols, row;
 987         int column_width = 0;
 988         int nfiles = num_matches;
 989         int nrows = nfiles;
 990         int l;
 991
 992         /* find the longest file name - use that as the column width */
 993         for (row = 0; row < nrows; row++) {
 994                 l = unicode_strwidth(matches[row]);
 995                 if (column_width < l)
 996                         column_width = l;
 997         }
 998         column_width += 2;              /* min space for columns */
 999         ncols = cmdedit_termw / column_width;
1000
1001         if (ncols > 1) {
1002                 nrows /= ncols;
1003                 if (nfiles % ncols)
1004                         nrows++;        /* round up fractionals */
1005         } else {
1006                 ncols = 1;
1007         }
1008         for (row = 0; row < nrows; row++) {
1009                 int n = row;
1010                 int nc;
1011
1012                 for (nc = 1; nc < ncols && n+nrows < nfiles; n += nrows, nc++) {
1013                         printf("%s%-*s", matches[n],
1014                                 (int)(column_width - unicode_strwidth(matches[n])), ""
1015                         );
1016                 }
1017                 if (ENABLE_UNICODE_SUPPORT)
1018                         puts(printable_string(NULL, matches[n]));
1019                 else
1020                         puts(matches[n]);
1021         }
1022 }
1023
1024 static const char *is_special_char(char c)
1025 {
1026         return strchr(" `\"#$%^&*()=+{}[]:;'|\\<>", c);
1027 }
1028
1029 static char *quote_special_chars(char *found)
1030 {
1031         int l = 0;
1032         char *s = xzalloc((strlen(found) + 1) * 2);
1033
1034         while (*found) {
1035                 if (is_special_char(*found))
1036                         s[l++] = '\\';
1037                 s[l++] = *found++;
1038         }
1039         /* s[l] = '\0'; - already is */
1040         return s;
1041 }
1042
1043 /* Do TAB completion */
1044 static NOINLINE void input_tab(smallint *lastWasTab)
1045 {
1046         char *chosen_match;
1047         char *match_buf;
1048         size_t len_found;
1049         /* Length of string used for matching */
1050         unsigned match_pfx_len = match_pfx_len;
1051         int find_type;
1052 # if ENABLE_UNICODE_SUPPORT
1053         /* cursor pos in command converted to multibyte form */
1054         int cursor_mb;
1055 # endif
1056         if (!(state->flags & TAB_COMPLETION))
1057                 return;
1058
1059         if (*lastWasTab) {
1060                 /* The last char was a TAB too.
1061                  * Print a list of all the available choices.
1062                  */
1063                 if (num_matches > 0) {
1064                         /* cursor will be changed by goto_new_line() */
1065                         int sav_cursor = cursor;
1066                         goto_new_line();
1067                         showfiles();
1068                         redraw(0, command_len - sav_cursor);
1069                 }
1070                 return;
1071         }
1072
1073         *lastWasTab = 1;
1074         chosen_match = NULL;
1075
1076         /* Make a local copy of the string up to the position of the cursor.
1077          * build_match_prefix will expand it into int16_t's, need to allocate
1078          * twice as much as the string_len+1.
1079          * (we then also (ab)use this extra space later - see (**))
1080          */
1081         match_buf = xmalloc(MAX_LINELEN * sizeof(int16_t));
1082 # if !ENABLE_UNICODE_SUPPORT
1083         save_string(match_buf, cursor + 1); /* +1 for NUL */
1084 # else
1085         {
1086                 CHAR_T wc = command_ps[cursor];
1087                 command_ps[cursor] = BB_NUL;
1088                 save_string(match_buf, MAX_LINELEN);
1089                 command_ps[cursor] = wc;
1090                 cursor_mb = strlen(match_buf);
1091         }
1092 # endif
1093         find_type = build_match_prefix(match_buf);
1094
1095         /* Free up any memory already allocated */
1096         free_tab_completion_data();
1097
1098 # if ENABLE_FEATURE_USERNAME_COMPLETION
1099         /* If the word starts with ~ and there is no slash in the word,
1100          * then try completing this word as a username. */
1101         if (state->flags & USERNAME_COMPLETION)
1102                 if (match_buf[0] == '~' && strchr(match_buf, '/') == NULL)
1103                         match_pfx_len = complete_username(match_buf);
1104 # endif
1105         /* If complete_username() did not match,
1106          * try to match a command in $PATH, or a directory, or a file */
1107         if (!matches)
1108                 match_pfx_len = complete_cmd_dir_file(match_buf, find_type);
1109
1110         /* Account for backslashes which will be inserted
1111          * by quote_special_chars() later */
1112         {
1113                 const char *e = match_buf + strlen(match_buf);
1114                 const char *s = e - match_pfx_len;
1115                 while (s < e)
1116                         if (is_special_char(*s++))
1117                                 match_pfx_len++;
1118         }
1119
1120         /* Remove duplicates */
1121         if (matches) {
1122                 unsigned i, n = 0;
1123                 qsort_string_vector(matches, num_matches);
1124                 for (i = 0; i < num_matches - 1; ++i) {
1125                         //if (matches[i] && matches[i+1]) { /* paranoia */
1126                                 if (strcmp(matches[i], matches[i+1]) == 0) {
1127                                         free(matches[i]);
1128                                         //matches[i] = NULL; /* paranoia */
1129                                 } else {
1130                                         matches[n++] = matches[i];
1131                                 }
1132                         //}
1133                 }
1134                 matches[n++] = matches[i];
1135                 num_matches = n;
1136         }
1137
1138         /* Did we find exactly one match? */
1139         if (num_matches != 1) { /* no */
1140                 char *cp;
1141                 beep();
1142                 if (!matches)
1143                         goto ret; /* no matches at all */
1144                 /* Find common prefix */
1145                 chosen_match = xstrdup(matches[0]);
1146                 for (cp = chosen_match; *cp; cp++) {
1147                         unsigned n;
1148                         for (n = 1; n < num_matches; n++) {
1149                                 if (matches[n][cp - chosen_match] != *cp) {
1150                                         goto stop;
1151                                 }
1152                         }
1153                 }
1154  stop:
1155                 if (cp == chosen_match) { /* have unique prefix? */
1156                         goto ret; /* no */
1157                 }
1158                 *cp = '\0';
1159                 cp = quote_special_chars(chosen_match);
1160                 free(chosen_match);
1161                 chosen_match = cp;
1162                 len_found = strlen(chosen_match);
1163         } else {                        /* exactly one match */
1164                 /* Next <tab> is not a double-tab */
1165                 *lastWasTab = 0;
1166
1167                 chosen_match = quote_special_chars(matches[0]);
1168                 len_found = strlen(chosen_match);
1169                 if (chosen_match[len_found-1] != '/') {
1170                         chosen_match[len_found] = ' ';
1171                         chosen_match[++len_found] = '\0';
1172                 }
1173         }
1174
1175 # if !ENABLE_UNICODE_SUPPORT
1176         /* Have space to place the match? */
1177         /* The result consists of three parts with these lengths: */
1178         /* cursor + (len_found - match_pfx_len) + (command_len - cursor) */
1179         /* it simplifies into: */
1180         if ((int)(len_found - match_pfx_len + command_len) < S.maxsize) {
1181                 int pos;
1182                 /* save tail */
1183                 strcpy(match_buf, &command_ps[cursor]);
1184                 /* add match and tail */
1185                 sprintf(&command_ps[cursor], "%s%s", chosen_match + match_pfx_len, match_buf);
1186                 command_len = strlen(command_ps);
1187                 /* new pos */
1188                 pos = cursor + len_found - match_pfx_len;
1189                 /* write out the matched command */
1190                 redraw(cmdedit_y, command_len - pos);
1191         }
1192 # else
1193         {
1194                 /* Use 2nd half of match_buf as scratch space - see (**) */
1195                 char *command = match_buf + MAX_LINELEN;
1196                 int len = save_string(command, MAX_LINELEN);
1197                 /* Have space to place the match? */
1198                 /* cursor_mb + (len_found - match_pfx_len) + (len - cursor_mb) */
1199                 if ((int)(len_found - match_pfx_len + len) < MAX_LINELEN) {
1200                         int pos;
1201                         /* save tail */
1202                         strcpy(match_buf, &command[cursor_mb]);
1203                         /* where do we want to have cursor after all? */
1204                         strcpy(&command[cursor_mb], chosen_match + match_pfx_len);
1205                         len = load_string(command, S.maxsize);
1206                         /* add match and tail */
1207                         sprintf(&command[cursor_mb], "%s%s", chosen_match + match_pfx_len, match_buf);
1208                         command_len = load_string(command, S.maxsize);
1209                         /* write out the matched command */
1210                         /* paranoia: load_string can return 0 on conv error,
1211                          * prevent passing pos = (0 - 12) to redraw */
1212                         pos = command_len - len;
1213                         redraw(cmdedit_y, pos >= 0 ? pos : 0);
1214                 }
1215         }
1216 # endif
1217  ret:
1218         free(chosen_match);
1219         free(match_buf);
1220 }
1221
1222 #endif  /* FEATURE_TAB_COMPLETION */
1223
1224
1225 line_input_t* FAST_FUNC new_line_input_t(int flags)
1226 {
1227         line_input_t *n = xzalloc(sizeof(*n));
1228         n->flags = flags;
1229         return n;
1230 }
1231
1232
1233 #if MAX_HISTORY > 0
1234
1235 static void save_command_ps_at_cur_history(void)
1236 {
1237         if (command_ps[0] != BB_NUL) {
1238                 int cur = state->cur_history;
1239                 free(state->history[cur]);
1240
1241 # if ENABLE_UNICODE_SUPPORT
1242                 {
1243                         char tbuf[MAX_LINELEN];
1244                         save_string(tbuf, sizeof(tbuf));
1245                         state->history[cur] = xstrdup(tbuf);
1246                 }
1247 # else
1248                 state->history[cur] = xstrdup(command_ps);
1249 # endif
1250         }
1251 }
1252
1253 /* state->flags is already checked to be nonzero */
1254 static int get_previous_history(void)
1255 {
1256         if ((state->flags & DO_HISTORY) && state->cur_history) {
1257                 save_command_ps_at_cur_history();
1258                 state->cur_history--;
1259                 return 1;
1260         }
1261         beep();
1262         return 0;
1263 }
1264
1265 static int get_next_history(void)
1266 {
1267         if (state->flags & DO_HISTORY) {
1268                 if (state->cur_history < state->cnt_history) {
1269                         save_command_ps_at_cur_history(); /* save the current history line */
1270                         return ++state->cur_history;
1271                 }
1272         }
1273         beep();
1274         return 0;
1275 }
1276
1277 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
1278 /* We try to ensure that concurrent additions to the history
1279  * do not overwrite each other.
1280  * Otherwise shell users get unhappy.
1281  *
1282  * History file is trimmed lazily, when it grows several times longer
1283  * than configured MAX_HISTORY lines.
1284  */
1285
1286 static void free_line_input_t(line_input_t *n)
1287 {
1288         int i = n->cnt_history;
1289         while (i > 0)
1290                 free(n->history[--i]);
1291         free(n);
1292 }
1293
1294 /* state->flags is already checked to be nonzero */
1295 static void load_history(line_input_t *st_parm)
1296 {
1297         char *temp_h[MAX_HISTORY];
1298         char *line;
1299         FILE *fp;
1300         unsigned idx, i, line_len;
1301
1302         /* NB: do not trash old history if file can't be opened */
1303
1304         fp = fopen_for_read(st_parm->hist_file);
1305         if (fp) {
1306                 /* clean up old history */
1307                 for (idx = st_parm->cnt_history; idx > 0;) {
1308                         idx--;
1309                         free(st_parm->history[idx]);
1310                         st_parm->history[idx] = NULL;
1311                 }
1312
1313                 /* fill temp_h[], retaining only last MAX_HISTORY lines */
1314                 memset(temp_h, 0, sizeof(temp_h));
1315                 st_parm->cnt_history_in_file = idx = 0;
1316                 while ((line = xmalloc_fgetline(fp)) != NULL) {
1317                         if (line[0] == '\0') {
1318                                 free(line);
1319                                 continue;
1320                         }
1321                         free(temp_h[idx]);
1322                         temp_h[idx] = line;
1323                         st_parm->cnt_history_in_file++;
1324                         idx++;
1325                         if (idx == MAX_HISTORY)
1326                                 idx = 0;
1327                 }
1328                 fclose(fp);
1329
1330                 /* find first non-NULL temp_h[], if any */
1331                 if (st_parm->cnt_history_in_file) {
1332                         while (temp_h[idx] == NULL) {
1333                                 idx++;
1334                                 if (idx == MAX_HISTORY)
1335                                         idx = 0;
1336                         }
1337                 }
1338
1339                 /* copy temp_h[] to st_parm->history[] */
1340                 for (i = 0; i < MAX_HISTORY;) {
1341                         line = temp_h[idx];
1342                         if (!line)
1343                                 break;
1344                         idx++;
1345                         if (idx == MAX_HISTORY)
1346                                 idx = 0;
1347                         line_len = strlen(line);
1348                         if (line_len >= MAX_LINELEN)
1349                                 line[MAX_LINELEN-1] = '\0';
1350                         st_parm->history[i++] = line;
1351                 }
1352                 st_parm->cnt_history = i;
1353         }
1354 }
1355
1356 /* state->flags is already checked to be nonzero */
1357 static void save_history(char *str)
1358 {
1359         int fd;
1360         int len, len2;
1361
1362         fd = open(state->hist_file, O_WRONLY | O_CREAT | O_APPEND, 0600);
1363         if (fd < 0)
1364                 return;
1365         xlseek(fd, 0, SEEK_END); /* paranoia */
1366         len = strlen(str);
1367         str[len] = '\n'; /* we (try to) do atomic write */
1368         len2 = full_write(fd, str, len + 1);
1369         str[len] = '\0';
1370         close(fd);
1371         if (len2 != len + 1)
1372                 return; /* "wtf?" */
1373
1374         /* did we write so much that history file needs trimming? */
1375         state->cnt_history_in_file++;
1376         if (state->cnt_history_in_file > MAX_HISTORY * 4) {
1377                 char *new_name;
1378                 line_input_t *st_temp;
1379
1380                 /* we may have concurrently written entries from others.
1381                  * load them */
1382                 st_temp = new_line_input_t(state->flags);
1383                 st_temp->hist_file = state->hist_file;
1384                 load_history(st_temp);
1385
1386                 /* write out temp file and replace hist_file atomically */
1387                 new_name = xasprintf("%s.%u.new", state->hist_file, (int) getpid());
1388                 fd = open(state->hist_file, O_WRONLY | O_CREAT | O_TRUNC, 0600);
1389                 if (fd >= 0) {
1390                         FILE *fp;
1391                         int i;
1392
1393                         fp = xfdopen_for_write(fd);
1394                         for (i = 0; i < st_temp->cnt_history; i++)
1395                                 fprintf(fp, "%s\n", st_temp->history[i]);
1396                         fclose(fp);
1397                         if (rename(new_name, state->hist_file) == 0)
1398                                 state->cnt_history_in_file = st_temp->cnt_history;
1399                 }
1400                 free(new_name);
1401                 free_line_input_t(st_temp);
1402         }
1403 }
1404 # else
1405 #  define load_history(a) ((void)0)
1406 #  define save_history(a) ((void)0)
1407 # endif /* FEATURE_COMMAND_SAVEHISTORY */
1408
1409 static void remember_in_history(char *str)
1410 {
1411         int i;
1412
1413         if (!(state->flags & DO_HISTORY))
1414                 return;
1415         if (str[0] == '\0')
1416                 return;
1417         i = state->cnt_history;
1418         /* Don't save dupes */
1419         if (i && strcmp(state->history[i-1], str) == 0)
1420                 return;
1421
1422         free(state->history[MAX_HISTORY]); /* redundant, paranoia */
1423         state->history[MAX_HISTORY] = NULL; /* redundant, paranoia */
1424
1425         /* If history[] is full, remove the oldest command */
1426         /* we need to keep history[MAX_HISTORY] empty, hence >=, not > */
1427         if (i >= MAX_HISTORY) {
1428                 free(state->history[0]);
1429                 for (i = 0; i < MAX_HISTORY-1; i++)
1430                         state->history[i] = state->history[i+1];
1431                 /* i == MAX_HISTORY-1 */
1432         }
1433         /* i <= MAX_HISTORY-1 */
1434         state->history[i++] = xstrdup(str);
1435         /* i <= MAX_HISTORY */
1436         state->cur_history = i;
1437         state->cnt_history = i;
1438 # if MAX_HISTORY > 0 && ENABLE_FEATURE_EDITING_SAVEHISTORY
1439         if ((state->flags & SAVE_HISTORY) && state->hist_file)
1440                 save_history(str);
1441 # endif
1442         IF_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines++;)
1443 }
1444
1445 #else /* MAX_HISTORY == 0 */
1446 # define remember_in_history(a) ((void)0)
1447 #endif /* MAX_HISTORY */
1448
1449
1450 #if ENABLE_FEATURE_EDITING_VI
1451 /*
1452  * vi mode implemented 2005 by Paul Fox <pgf@foxharp.boston.ma.us>
1453  */
1454 static void
1455 vi_Word_motion(int eat)
1456 {
1457         CHAR_T *command = command_ps;
1458
1459         while (cursor < command_len && !BB_isspace(command[cursor]))
1460                 input_forward();
1461         if (eat) while (cursor < command_len && BB_isspace(command[cursor]))
1462                 input_forward();
1463 }
1464
1465 static void
1466 vi_word_motion(int eat)
1467 {
1468         CHAR_T *command = command_ps;
1469
1470         if (BB_isalnum(command[cursor]) || command[cursor] == '_') {
1471                 while (cursor < command_len
1472                  && (BB_isalnum(command[cursor+1]) || command[cursor+1] == '_')
1473                 ) {
1474                         input_forward();
1475                 }
1476         } else if (BB_ispunct(command[cursor])) {
1477                 while (cursor < command_len && BB_ispunct(command[cursor+1]))
1478                         input_forward();
1479         }
1480
1481         if (cursor < command_len)
1482                 input_forward();
1483
1484         if (eat) {
1485                 while (cursor < command_len && BB_isspace(command[cursor]))
1486                         input_forward();
1487         }
1488 }
1489
1490 static void
1491 vi_End_motion(void)
1492 {
1493         CHAR_T *command = command_ps;
1494
1495         input_forward();
1496         while (cursor < command_len && BB_isspace(command[cursor]))
1497                 input_forward();
1498         while (cursor < command_len-1 && !BB_isspace(command[cursor+1]))
1499                 input_forward();
1500 }
1501
1502 static void
1503 vi_end_motion(void)
1504 {
1505         CHAR_T *command = command_ps;
1506
1507         if (cursor >= command_len-1)
1508                 return;
1509         input_forward();
1510         while (cursor < command_len-1 && BB_isspace(command[cursor]))
1511                 input_forward();
1512         if (cursor >= command_len-1)
1513                 return;
1514         if (BB_isalnum(command[cursor]) || command[cursor] == '_') {
1515                 while (cursor < command_len-1
1516                  && (BB_isalnum(command[cursor+1]) || command[cursor+1] == '_')
1517                 ) {
1518                         input_forward();
1519                 }
1520         } else if (BB_ispunct(command[cursor])) {
1521                 while (cursor < command_len-1 && BB_ispunct(command[cursor+1]))
1522                         input_forward();
1523         }
1524 }
1525
1526 static void
1527 vi_Back_motion(void)
1528 {
1529         CHAR_T *command = command_ps;
1530
1531         while (cursor > 0 && BB_isspace(command[cursor-1]))
1532                 input_backward(1);
1533         while (cursor > 0 && !BB_isspace(command[cursor-1]))
1534                 input_backward(1);
1535 }
1536
1537 static void
1538 vi_back_motion(void)
1539 {
1540         CHAR_T *command = command_ps;
1541
1542         if (cursor <= 0)
1543                 return;
1544         input_backward(1);
1545         while (cursor > 0 && BB_isspace(command[cursor]))
1546                 input_backward(1);
1547         if (cursor <= 0)
1548                 return;
1549         if (BB_isalnum(command[cursor]) || command[cursor] == '_') {
1550                 while (cursor > 0
1551                  && (BB_isalnum(command[cursor-1]) || command[cursor-1] == '_')
1552                 ) {
1553                         input_backward(1);
1554                 }
1555         } else if (BB_ispunct(command[cursor])) {
1556                 while (cursor > 0 && BB_ispunct(command[cursor-1]))
1557                         input_backward(1);
1558         }
1559 }
1560 #endif
1561
1562 /* Modelled after bash 4.0 behavior of Ctrl-<arrow> */
1563 static void ctrl_left(void)
1564 {
1565         CHAR_T *command = command_ps;
1566
1567         while (1) {
1568                 CHAR_T c;
1569
1570                 input_backward(1);
1571                 if (cursor == 0)
1572                         break;
1573                 c = command[cursor];
1574                 if (c != ' ' && !BB_ispunct(c)) {
1575                         /* we reached a "word" delimited by spaces/punct.
1576                          * go to its beginning */
1577                         while (1) {
1578                                 c = command[cursor - 1];
1579                                 if (c == ' ' || BB_ispunct(c))
1580                                         break;
1581                                 input_backward(1);
1582                                 if (cursor == 0)
1583                                         break;
1584                         }
1585                         break;
1586                 }
1587         }
1588 }
1589 static void ctrl_right(void)
1590 {
1591         CHAR_T *command = command_ps;
1592
1593         while (1) {
1594                 CHAR_T c;
1595
1596                 c = command[cursor];
1597                 if (c == BB_NUL)
1598                         break;
1599                 if (c != ' ' && !BB_ispunct(c)) {
1600                         /* we reached a "word" delimited by spaces/punct.
1601                          * go to its end + 1 */
1602                         while (1) {
1603                                 input_forward();
1604                                 c = command[cursor];
1605                                 if (c == BB_NUL || c == ' ' || BB_ispunct(c))
1606                                         break;
1607                         }
1608                         break;
1609                 }
1610                 input_forward();
1611         }
1612 }
1613
1614
1615 /*
1616  * read_line_input and its helpers
1617  */
1618
1619 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
1620 static void ask_terminal(void)
1621 {
1622         /* Ask terminal where is the cursor now.
1623          * lineedit_read_key handles response and corrects
1624          * our idea of current cursor position.
1625          * Testcase: run "echo -n long_line_long_line_long_line",
1626          * then type in a long, wrapping command and try to
1627          * delete it using backspace key.
1628          * Note: we print it _after_ prompt, because
1629          * prompt may contain CR. Example: PS1='\[\r\n\]\w '
1630          */
1631         /* Problem: if there is buffered input on stdin,
1632          * the response will be delivered later,
1633          * possibly to an unsuspecting application.
1634          * Testcase: "sleep 1; busybox ash" + press and hold [Enter].
1635          * Result:
1636          * ~/srcdevel/bbox/fix/busybox.t4 #
1637          * ~/srcdevel/bbox/fix/busybox.t4 #
1638          * ^[[59;34~/srcdevel/bbox/fix/busybox.t4 #  <-- garbage
1639          * ~/srcdevel/bbox/fix/busybox.t4 #
1640          *
1641          * Checking for input with poll only makes the race narrower,
1642          * I still can trigger it. Strace:
1643          *
1644          * write(1, "~/srcdevel/bbox/fix/busybox.t4 # ", 33) = 33
1645          * poll([{fd=0, events=POLLIN}], 1, 0) = 0 (Timeout)  <-- no input exists
1646          * write(1, "\33[6n", 4) = 4  <-- send the ESC sequence, quick!
1647          * poll([{fd=0, events=POLLIN}], 1, 4294967295) = 1 ([{fd=0, revents=POLLIN}])
1648          * read(0, "\n", 1)      = 1  <-- oh crap, user's input got in first
1649          */
1650         struct pollfd pfd;
1651
1652         pfd.fd = STDIN_FILENO;
1653         pfd.events = POLLIN;
1654         if (safe_poll(&pfd, 1, 0) == 0) {
1655                 S.sent_ESC_br6n = 1;
1656                 fputs(ESC"[6n", stdout);
1657                 fflush_all(); /* make terminal see it ASAP! */
1658         }
1659 }
1660 #else
1661 #define ask_terminal() ((void)0)
1662 #endif
1663
1664 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1665 static void parse_and_put_prompt(const char *prmt_ptr)
1666 {
1667         cmdedit_prompt = prmt_ptr;
1668         cmdedit_prmt_len = strlen(prmt_ptr);
1669         put_prompt();
1670 }
1671 #else
1672 static void parse_and_put_prompt(const char *prmt_ptr)
1673 {
1674         int prmt_len = 0;
1675         size_t cur_prmt_len = 0;
1676         char flg_not_length = '[';
1677         char *prmt_mem_ptr = xzalloc(1);
1678         char *cwd_buf = xrealloc_getcwd_or_warn(NULL);
1679         char cbuf[2];
1680         char c;
1681         char *pbuf;
1682
1683         cmdedit_prmt_len = 0;
1684
1685         if (!cwd_buf) {
1686                 cwd_buf = (char *)bb_msg_unknown;
1687         }
1688
1689         cbuf[1] = '\0'; /* never changes */
1690
1691         while (*prmt_ptr) {
1692                 char *free_me = NULL;
1693
1694                 pbuf = cbuf;
1695                 c = *prmt_ptr++;
1696                 if (c == '\\') {
1697                         const char *cp = prmt_ptr;
1698                         int l;
1699
1700                         c = bb_process_escape_sequence(&prmt_ptr);
1701                         if (prmt_ptr == cp) {
1702                                 if (*cp == '\0')
1703                                         break;
1704                                 c = *prmt_ptr++;
1705
1706                                 switch (c) {
1707 # if ENABLE_USERNAME_OR_HOMEDIR
1708                                 case 'u':
1709                                         pbuf = user_buf ? user_buf : (char*)"";
1710                                         break;
1711 # endif
1712                                 case 'h':
1713                                         pbuf = free_me = safe_gethostname();
1714                                         *strchrnul(pbuf, '.') = '\0';
1715                                         break;
1716                                 case '$':
1717                                         c = (geteuid() == 0 ? '#' : '$');
1718                                         break;
1719 # if ENABLE_USERNAME_OR_HOMEDIR
1720                                 case 'w':
1721                                         /* /home/user[/something] -> ~[/something] */
1722                                         pbuf = cwd_buf;
1723                                         l = strlen(home_pwd_buf);
1724                                         if (l != 0
1725                                          && strncmp(home_pwd_buf, cwd_buf, l) == 0
1726                                          && (cwd_buf[l]=='/' || cwd_buf[l]=='\0')
1727                                          && strlen(cwd_buf + l) < PATH_MAX
1728                                         ) {
1729                                                 pbuf = free_me = xasprintf("~%s", cwd_buf + l);
1730                                         }
1731                                         break;
1732 # endif
1733                                 case 'W':
1734                                         pbuf = cwd_buf;
1735                                         cp = strrchr(pbuf, '/');
1736                                         if (cp != NULL && cp != pbuf)
1737                                                 pbuf += (cp-pbuf) + 1;
1738                                         break;
1739                                 case '!':
1740                                         pbuf = free_me = xasprintf("%d", num_ok_lines);
1741                                         break;
1742                                 case 'e': case 'E':     /* \e \E = \033 */
1743                                         c = '\033';
1744                                         break;
1745                                 case 'x': case 'X': {
1746                                         char buf2[4];
1747                                         for (l = 0; l < 3;) {
1748                                                 unsigned h;
1749                                                 buf2[l++] = *prmt_ptr;
1750                                                 buf2[l] = '\0';
1751                                                 h = strtoul(buf2, &pbuf, 16);
1752                                                 if (h > UCHAR_MAX || (pbuf - buf2) < l) {
1753                                                         buf2[--l] = '\0';
1754                                                         break;
1755                                                 }
1756                                                 prmt_ptr++;
1757                                         }
1758                                         c = (char)strtoul(buf2, NULL, 16);
1759                                         if (c == 0)
1760                                                 c = '?';
1761                                         pbuf = cbuf;
1762                                         break;
1763                                 }
1764                                 case '[': case ']':
1765                                         if (c == flg_not_length) {
1766                                                 flg_not_length = (flg_not_length == '[' ? ']' : '[');
1767                                                 continue;
1768                                         }
1769                                         break;
1770                                 } /* switch */
1771                         } /* if */
1772                 } /* if */
1773                 cbuf[0] = c;
1774                 cur_prmt_len = strlen(pbuf);
1775                 prmt_len += cur_prmt_len;
1776                 if (flg_not_length != ']')
1777                         cmdedit_prmt_len += cur_prmt_len;
1778                 prmt_mem_ptr = strcat(xrealloc(prmt_mem_ptr, prmt_len+1), pbuf);
1779                 free(free_me);
1780         } /* while */
1781
1782         if (cwd_buf != (char *)bb_msg_unknown)
1783                 free(cwd_buf);
1784         cmdedit_prompt = prmt_mem_ptr;
1785         put_prompt();
1786 }
1787 #endif
1788
1789 static void cmdedit_setwidth(unsigned w, int redraw_flg)
1790 {
1791         cmdedit_termw = w;
1792         if (redraw_flg) {
1793                 /* new y for current cursor */
1794                 int new_y = (cursor + cmdedit_prmt_len) / w;
1795                 /* redraw */
1796                 redraw((new_y >= cmdedit_y ? new_y : cmdedit_y), command_len - cursor);
1797                 fflush_all();
1798         }
1799 }
1800
1801 static void win_changed(int nsig)
1802 {
1803         int sv_errno = errno;
1804         unsigned width;
1805         get_terminal_width_height(0, &width, NULL);
1806         cmdedit_setwidth(width, nsig /* - just a yes/no flag */);
1807         if (nsig == SIGWINCH)
1808                 signal(SIGWINCH, win_changed); /* rearm ourself */
1809         errno = sv_errno;
1810 }
1811
1812 static int lineedit_read_key(char *read_key_buffer)
1813 {
1814         int64_t ic;
1815         int timeout = -1;
1816 #if ENABLE_UNICODE_SUPPORT
1817         char unicode_buf[MB_CUR_MAX + 1];
1818         int unicode_idx = 0;
1819 #endif
1820
1821         while (1) {
1822                 /* Wait for input. TIMEOUT = -1 makes read_key wait even
1823                  * on nonblocking stdin, TIMEOUT = 50 makes sure we won't
1824                  * insist on full MB_CUR_MAX buffer to declare input like
1825                  * "\xff\n",pause,"ls\n" invalid and thus won't lose "ls".
1826                  *
1827                  * Note: read_key sets errno to 0 on success.
1828                  */
1829                 ic = read_key(STDIN_FILENO, read_key_buffer, timeout);
1830                 if (errno) {
1831 #if ENABLE_UNICODE_SUPPORT
1832                         if (errno == EAGAIN && unicode_idx != 0)
1833                                 goto pushback;
1834 #endif
1835                         break;
1836                 }
1837
1838 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
1839                 if ((int32_t)ic == KEYCODE_CURSOR_POS
1840                  && S.sent_ESC_br6n
1841                 ) {
1842                         S.sent_ESC_br6n = 0;
1843                         if (cursor == 0) { /* otherwise it may be bogus */
1844                                 int col = ((ic >> 32) & 0x7fff) - 1;
1845                                 if (col > cmdedit_prmt_len) {
1846                                         cmdedit_x += (col - cmdedit_prmt_len);
1847                                         while (cmdedit_x >= cmdedit_termw) {
1848                                                 cmdedit_x -= cmdedit_termw;
1849                                                 cmdedit_y++;
1850                                         }
1851                                 }
1852                         }
1853                         continue;
1854                 }
1855 #endif
1856
1857 #if ENABLE_UNICODE_SUPPORT
1858                 if (unicode_status == UNICODE_ON) {
1859                         wchar_t wc;
1860
1861                         if ((int32_t)ic < 0) /* KEYCODE_xxx */
1862                                 break;
1863                         // TODO: imagine sequence like: 0xff,<left-arrow>: we are currently losing 0xff...
1864
1865                         unicode_buf[unicode_idx++] = ic;
1866                         unicode_buf[unicode_idx] = '\0';
1867                         if (mbstowcs(&wc, unicode_buf, 1) != 1) {
1868                                 /* Not (yet?) a valid unicode char */
1869                                 if (unicode_idx < MB_CUR_MAX) {
1870                                         timeout = 50;
1871                                         continue;
1872                                 }
1873  pushback:
1874                                 /* Invalid sequence. Save all "bad bytes" except first */
1875                                 read_key_ungets(read_key_buffer, unicode_buf + 1, unicode_idx - 1);
1876 # if !ENABLE_UNICODE_PRESERVE_BROKEN
1877                                 ic = CONFIG_SUBST_WCHAR;
1878 # else
1879                                 ic = unicode_mark_raw_byte(unicode_buf[0]);
1880 # endif
1881                         } else {
1882                                 /* Valid unicode char, return its code */
1883                                 ic = wc;
1884                         }
1885                 }
1886 #endif
1887                 break;
1888         }
1889
1890         return ic;
1891 }
1892
1893 #if ENABLE_UNICODE_BIDI_SUPPORT
1894 static int isrtl_str(void)
1895 {
1896         int idx = cursor;
1897
1898         while (idx < command_len && unicode_bidi_is_neutral_wchar(command_ps[idx]))
1899                 idx++;
1900         return unicode_bidi_isrtl(command_ps[idx]);
1901 }
1902 #else
1903 # define isrtl_str() 0
1904 #endif
1905
1906 /* leave out the "vi-mode"-only case labels if vi editing isn't
1907  * configured. */
1908 #define vi_case(caselabel) IF_FEATURE_EDITING_VI(case caselabel)
1909
1910 /* convert uppercase ascii to equivalent control char, for readability */
1911 #undef CTRL
1912 #define CTRL(a) ((a) & ~0x40)
1913
1914 /* maxsize must be >= 2.
1915  * Returns:
1916  * -1 on read errors or EOF, or on bare Ctrl-D,
1917  * 0  on ctrl-C (the line entered is still returned in 'command'),
1918  * >0 length of input string, including terminating '\n'
1919  */
1920 int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, line_input_t *st)
1921 {
1922         int len;
1923 #if ENABLE_FEATURE_TAB_COMPLETION
1924         smallint lastWasTab = 0;
1925 #endif
1926         smallint break_out = 0;
1927 #if ENABLE_FEATURE_EDITING_VI
1928         smallint vi_cmdmode = 0;
1929 #endif
1930         struct termios initial_settings;
1931         struct termios new_settings;
1932         char read_key_buffer[KEYCODE_BUFFER_SIZE];
1933
1934         INIT_S();
1935
1936         if (tcgetattr(STDIN_FILENO, &initial_settings) < 0
1937          || !(initial_settings.c_lflag & ECHO)
1938         ) {
1939                 /* Happens when e.g. stty -echo was run before */
1940                 parse_and_put_prompt(prompt);
1941                 /* fflush_all(); - done by parse_and_put_prompt */
1942                 if (fgets(command, maxsize, stdin) == NULL)
1943                         len = -1; /* EOF or error */
1944                 else
1945                         len = strlen(command);
1946                 DEINIT_S();
1947                 return len;
1948         }
1949
1950         init_unicode();
1951
1952 // FIXME: audit & improve this
1953         if (maxsize > MAX_LINELEN)
1954                 maxsize = MAX_LINELEN;
1955         S.maxsize = maxsize;
1956
1957         /* With null flags, no other fields are ever used */
1958         state = st ? st : (line_input_t*) &const_int_0;
1959 #if MAX_HISTORY > 0
1960 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
1961         if ((state->flags & SAVE_HISTORY) && state->hist_file)
1962                 if (state->cnt_history == 0)
1963                         load_history(state);
1964 # endif
1965         if (state->flags & DO_HISTORY)
1966                 state->cur_history = state->cnt_history;
1967 #endif
1968
1969         /* prepare before init handlers */
1970         cmdedit_y = 0;  /* quasireal y, not true if line > xt*yt */
1971         command_len = 0;
1972 #if ENABLE_UNICODE_SUPPORT
1973         command_ps = xzalloc(maxsize * sizeof(command_ps[0]));
1974 #else
1975         command_ps = command;
1976         command[0] = '\0';
1977 #endif
1978 #define command command_must_not_be_used
1979
1980         new_settings = initial_settings;
1981         new_settings.c_lflag &= ~ICANON;        /* unbuffered input */
1982         /* Turn off echoing and CTRL-C, so we can trap it */
1983         new_settings.c_lflag &= ~(ECHO | ECHONL | ISIG);
1984         /* Hmm, in linux c_cc[] is not parsed if ICANON is off */
1985         new_settings.c_cc[VMIN] = 1;
1986         new_settings.c_cc[VTIME] = 0;
1987         /* Turn off CTRL-C, so we can trap it */
1988 #ifndef _POSIX_VDISABLE
1989 # define _POSIX_VDISABLE '\0'
1990 #endif
1991         new_settings.c_cc[VINTR] = _POSIX_VDISABLE;
1992         tcsetattr_stdin_TCSANOW(&new_settings);
1993
1994         /* Now initialize things */
1995         previous_SIGWINCH_handler = signal(SIGWINCH, win_changed);
1996         win_changed(0); /* do initial resizing */
1997 #if ENABLE_USERNAME_OR_HOMEDIR
1998         {
1999                 struct passwd *entry;
2000
2001                 entry = getpwuid(geteuid());
2002                 if (entry) {
2003                         user_buf = xstrdup(entry->pw_name);
2004                         home_pwd_buf = xstrdup(entry->pw_dir);
2005                 }
2006         }
2007 #endif
2008
2009 #if 0
2010         for (i = 0; i <= MAX_HISTORY; i++)
2011                 bb_error_msg("history[%d]:'%s'", i, state->history[i]);
2012         bb_error_msg("cur_history:%d cnt_history:%d", state->cur_history, state->cnt_history);
2013 #endif
2014
2015         /* Print out the command prompt, optionally ask where cursor is */
2016         parse_and_put_prompt(prompt);
2017         ask_terminal();
2018
2019         read_key_buffer[0] = 0;
2020         while (1) {
2021                 /*
2022                  * The emacs and vi modes share much of the code in the big
2023                  * command loop.  Commands entered when in vi's command mode
2024                  * (aka "escape mode") get an extra bit added to distinguish
2025                  * them - this keeps them from being self-inserted. This
2026                  * clutters the big switch a bit, but keeps all the code
2027                  * in one place.
2028                  */
2029                 enum {
2030                         VI_CMDMODE_BIT = 0x40000000,
2031                         /* 0x80000000 bit flags KEYCODE_xxx */
2032                 };
2033                 int32_t ic, ic_raw;
2034
2035                 fflush_all();
2036                 ic = ic_raw = lineedit_read_key(read_key_buffer);
2037
2038 #if ENABLE_FEATURE_EDITING_VI
2039                 newdelflag = 1;
2040                 if (vi_cmdmode) {
2041                         /* btw, since KEYCODE_xxx are all < 0, this doesn't
2042                          * change ic if it contains one of them: */
2043                         ic |= VI_CMDMODE_BIT;
2044                 }
2045 #endif
2046
2047                 switch (ic) {
2048                 case '\n':
2049                 case '\r':
2050                 vi_case('\n'|VI_CMDMODE_BIT:)
2051                 vi_case('\r'|VI_CMDMODE_BIT:)
2052                         /* Enter */
2053                         goto_new_line();
2054                         break_out = 1;
2055                         break;
2056                 case CTRL('A'):
2057                 vi_case('0'|VI_CMDMODE_BIT:)
2058                         /* Control-a -- Beginning of line */
2059                         input_backward(cursor);
2060                         break;
2061                 case CTRL('B'):
2062                 vi_case('h'|VI_CMDMODE_BIT:)
2063                 vi_case('\b'|VI_CMDMODE_BIT:) /* ^H */
2064                 vi_case('\x7f'|VI_CMDMODE_BIT:) /* DEL */
2065                         input_backward(1); /* Move back one character */
2066                         break;
2067                 case CTRL('E'):
2068                 vi_case('$'|VI_CMDMODE_BIT:)
2069                         /* Control-e -- End of line */
2070                         put_till_end_and_adv_cursor();
2071                         break;
2072                 case CTRL('F'):
2073                 vi_case('l'|VI_CMDMODE_BIT:)
2074                 vi_case(' '|VI_CMDMODE_BIT:)
2075                         input_forward(); /* Move forward one character */
2076                         break;
2077                 case '\b':   /* ^H */
2078                 case '\x7f': /* DEL */
2079                         if (!isrtl_str())
2080                                 input_backspace();
2081                         else
2082                                 input_delete(0);
2083                         break;
2084                 case KEYCODE_DELETE:
2085                         if (!isrtl_str())
2086                                 input_delete(0);
2087                         else
2088                                 input_backspace();
2089                         break;
2090 #if ENABLE_FEATURE_TAB_COMPLETION
2091                 case '\t':
2092                         input_tab(&lastWasTab);
2093                         break;
2094 #endif
2095                 case CTRL('K'):
2096                         /* Control-k -- clear to end of line */
2097                         command_ps[cursor] = BB_NUL;
2098                         command_len = cursor;
2099                         printf(SEQ_CLEAR_TILL_END_OF_SCREEN);
2100                         break;
2101                 case CTRL('L'):
2102                 vi_case(CTRL('L')|VI_CMDMODE_BIT:)
2103                         /* Control-l -- clear screen */
2104                         printf(ESC"[H"); /* cursor to top,left */
2105                         redraw(0, command_len - cursor);
2106                         break;
2107 #if MAX_HISTORY > 0
2108                 case CTRL('N'):
2109                 vi_case(CTRL('N')|VI_CMDMODE_BIT:)
2110                 vi_case('j'|VI_CMDMODE_BIT:)
2111                         /* Control-n -- Get next command in history */
2112                         if (get_next_history())
2113                                 goto rewrite_line;
2114                         break;
2115                 case CTRL('P'):
2116                 vi_case(CTRL('P')|VI_CMDMODE_BIT:)
2117                 vi_case('k'|VI_CMDMODE_BIT:)
2118                         /* Control-p -- Get previous command from history */
2119                         if (get_previous_history())
2120                                 goto rewrite_line;
2121                         break;
2122 #endif
2123                 case CTRL('U'):
2124                 vi_case(CTRL('U')|VI_CMDMODE_BIT:)
2125                         /* Control-U -- Clear line before cursor */
2126                         if (cursor) {
2127                                 command_len -= cursor;
2128                                 memmove(command_ps, command_ps + cursor,
2129                                         (command_len + 1) * sizeof(command_ps[0]));
2130                                 redraw(cmdedit_y, command_len);
2131                         }
2132                         break;
2133                 case CTRL('W'):
2134                 vi_case(CTRL('W')|VI_CMDMODE_BIT:)
2135                         /* Control-W -- Remove the last word */
2136                         while (cursor > 0 && BB_isspace(command_ps[cursor-1]))
2137                                 input_backspace();
2138                         while (cursor > 0 && !BB_isspace(command_ps[cursor-1]))
2139                                 input_backspace();
2140                         break;
2141
2142 #if ENABLE_FEATURE_EDITING_VI
2143                 case 'i'|VI_CMDMODE_BIT:
2144                         vi_cmdmode = 0;
2145                         break;
2146                 case 'I'|VI_CMDMODE_BIT:
2147                         input_backward(cursor);
2148                         vi_cmdmode = 0;
2149                         break;
2150                 case 'a'|VI_CMDMODE_BIT:
2151                         input_forward();
2152                         vi_cmdmode = 0;
2153                         break;
2154                 case 'A'|VI_CMDMODE_BIT:
2155                         put_till_end_and_adv_cursor();
2156                         vi_cmdmode = 0;
2157                         break;
2158                 case 'x'|VI_CMDMODE_BIT:
2159                         input_delete(1);
2160                         break;
2161                 case 'X'|VI_CMDMODE_BIT:
2162                         if (cursor > 0) {
2163                                 input_backward(1);
2164                                 input_delete(1);
2165                         }
2166                         break;
2167                 case 'W'|VI_CMDMODE_BIT:
2168                         vi_Word_motion(1);
2169                         break;
2170                 case 'w'|VI_CMDMODE_BIT:
2171                         vi_word_motion(1);
2172                         break;
2173                 case 'E'|VI_CMDMODE_BIT:
2174                         vi_End_motion();
2175                         break;
2176                 case 'e'|VI_CMDMODE_BIT:
2177                         vi_end_motion();
2178                         break;
2179                 case 'B'|VI_CMDMODE_BIT:
2180                         vi_Back_motion();
2181                         break;
2182                 case 'b'|VI_CMDMODE_BIT:
2183                         vi_back_motion();
2184                         break;
2185                 case 'C'|VI_CMDMODE_BIT:
2186                         vi_cmdmode = 0;
2187                         /* fall through */
2188                 case 'D'|VI_CMDMODE_BIT:
2189                         goto clear_to_eol;
2190
2191                 case 'c'|VI_CMDMODE_BIT:
2192                         vi_cmdmode = 0;
2193                         /* fall through */
2194                 case 'd'|VI_CMDMODE_BIT: {
2195                         int nc, sc;
2196
2197                         ic = lineedit_read_key(read_key_buffer);
2198                         if (errno) /* error */
2199                                 goto return_error_indicator;
2200                         if (ic == ic_raw) { /* "cc", "dd" */
2201                                 input_backward(cursor);
2202                                 goto clear_to_eol;
2203                                 break;
2204                         }
2205
2206                         sc = cursor;
2207                         switch (ic) {
2208                         case 'w':
2209                         case 'W':
2210                         case 'e':
2211                         case 'E':
2212                                 switch (ic) {
2213                                 case 'w':   /* "dw", "cw" */
2214                                         vi_word_motion(vi_cmdmode);
2215                                         break;
2216                                 case 'W':   /* 'dW', 'cW' */
2217                                         vi_Word_motion(vi_cmdmode);
2218                                         break;
2219                                 case 'e':   /* 'de', 'ce' */
2220                                         vi_end_motion();
2221                                         input_forward();
2222                                         break;
2223                                 case 'E':   /* 'dE', 'cE' */
2224                                         vi_End_motion();
2225                                         input_forward();
2226                                         break;
2227                                 }
2228                                 nc = cursor;
2229                                 input_backward(cursor - sc);
2230                                 while (nc-- > cursor)
2231                                         input_delete(1);
2232                                 break;
2233                         case 'b':  /* "db", "cb" */
2234                         case 'B':  /* implemented as B */
2235                                 if (ic == 'b')
2236                                         vi_back_motion();
2237                                 else
2238                                         vi_Back_motion();
2239                                 while (sc-- > cursor)
2240                                         input_delete(1);
2241                                 break;
2242                         case ' ':  /* "d ", "c " */
2243                                 input_delete(1);
2244                                 break;
2245                         case '$':  /* "d$", "c$" */
2246  clear_to_eol:
2247                                 while (cursor < command_len)
2248                                         input_delete(1);
2249                                 break;
2250                         }
2251                         break;
2252                 }
2253                 case 'p'|VI_CMDMODE_BIT:
2254                         input_forward();
2255                         /* fallthrough */
2256                 case 'P'|VI_CMDMODE_BIT:
2257                         put();
2258                         break;
2259                 case 'r'|VI_CMDMODE_BIT:
2260 //FIXME: unicode case?
2261                         ic = lineedit_read_key(read_key_buffer);
2262                         if (errno) /* error */
2263                                 goto return_error_indicator;
2264                         if (ic < ' ' || ic > 255) {
2265                                 beep();
2266                         } else {
2267                                 command_ps[cursor] = ic;
2268                                 bb_putchar(ic);
2269                                 bb_putchar('\b');
2270                         }
2271                         break;
2272                 case '\x1b': /* ESC */
2273                         if (state->flags & VI_MODE) {
2274                                 /* insert mode --> command mode */
2275                                 vi_cmdmode = 1;
2276                                 input_backward(1);
2277                         }
2278                         break;
2279 #endif /* FEATURE_COMMAND_EDITING_VI */
2280
2281 #if MAX_HISTORY > 0
2282                 case KEYCODE_UP:
2283                         if (get_previous_history())
2284                                 goto rewrite_line;
2285                         beep();
2286                         break;
2287                 case KEYCODE_DOWN:
2288                         if (!get_next_history())
2289                                 break;
2290  rewrite_line:
2291                         /* Rewrite the line with the selected history item */
2292                         /* change command */
2293                         command_len = load_string(state->history[state->cur_history] ?
2294                                         state->history[state->cur_history] : "", maxsize);
2295                         /* redraw and go to eol (bol, in vi) */
2296                         redraw(cmdedit_y, (state->flags & VI_MODE) ? 9999 : 0);
2297                         break;
2298 #endif
2299                 case KEYCODE_RIGHT:
2300                         input_forward();
2301                         break;
2302                 case KEYCODE_LEFT:
2303                         input_backward(1);
2304                         break;
2305                 case KEYCODE_CTRL_LEFT:
2306                         ctrl_left();
2307                         break;
2308                 case KEYCODE_CTRL_RIGHT:
2309                         ctrl_right();
2310                         break;
2311                 case KEYCODE_HOME:
2312                         input_backward(cursor);
2313                         break;
2314                 case KEYCODE_END:
2315                         put_till_end_and_adv_cursor();
2316                         break;
2317
2318                 default:
2319                         if (initial_settings.c_cc[VINTR] != 0
2320                          && ic_raw == initial_settings.c_cc[VINTR]
2321                         ) {
2322                                 /* Ctrl-C (usually) - stop gathering input */
2323                                 goto_new_line();
2324                                 command_len = 0;
2325                                 break_out = -1; /* "do not append '\n'" */
2326                                 break;
2327                         }
2328                         if (initial_settings.c_cc[VEOF] != 0
2329                          && ic_raw == initial_settings.c_cc[VEOF]
2330                         ) {
2331                                 /* Ctrl-D (usually) - delete one character,
2332                                  * or exit if len=0 and no chars to delete */
2333                                 if (command_len == 0) {
2334                                         errno = 0;
2335
2336                 case -1: /* error (e.g. EIO when tty is destroyed) */
2337  IF_FEATURE_EDITING_VI(return_error_indicator:)
2338                                         break_out = command_len = -1;
2339                                         break;
2340                                 }
2341                                 input_delete(0);
2342                                 break;
2343                         }
2344 //                      /* Control-V -- force insert of next char */
2345 //                      if (c == CTRL('V')) {
2346 //                              if (safe_read(STDIN_FILENO, &c, 1) < 1)
2347 //                                      goto return_error_indicator;
2348 //                              if (c == 0) {
2349 //                                      beep();
2350 //                                      break;
2351 //                              }
2352 //                      }
2353                         if (ic < ' '
2354                          || (!ENABLE_UNICODE_SUPPORT && ic >= 256)
2355                          || (ENABLE_UNICODE_SUPPORT && ic >= VI_CMDMODE_BIT)
2356                         ) {
2357                                 /* If VI_CMDMODE_BIT is set, ic is >= 256
2358                                  * and vi mode ignores unexpected chars.
2359                                  * Otherwise, we are here if ic is a
2360                                  * control char or an unhandled ESC sequence,
2361                                  * which is also ignored.
2362                                  */
2363                                 break;
2364                         }
2365                         if ((int)command_len >= (maxsize - 2)) {
2366                                 /* Not enough space for the char and EOL */
2367                                 break;
2368                         }
2369
2370                         command_len++;
2371                         if (cursor == (command_len - 1)) {
2372                                 /* We are at the end, append */
2373                                 command_ps[cursor] = ic;
2374                                 command_ps[cursor + 1] = BB_NUL;
2375                                 put_cur_glyph_and_inc_cursor();
2376                                 if (unicode_bidi_isrtl(ic))
2377                                         input_backward(1);
2378                         } else {
2379                                 /* In the middle, insert */
2380                                 int sc = cursor;
2381
2382                                 memmove(command_ps + sc + 1, command_ps + sc,
2383                                         (command_len - sc) * sizeof(command_ps[0]));
2384                                 command_ps[sc] = ic;
2385                                 /* is right-to-left char, or neutral one (e.g. comma) was just added to rtl text? */
2386                                 if (!isrtl_str())
2387                                         sc++; /* no */
2388                                 put_till_end_and_adv_cursor();
2389                                 /* to prev x pos + 1 */
2390                                 input_backward(cursor - sc);
2391                         }
2392                         break;
2393                 } /* switch (ic) */
2394
2395                 if (break_out)
2396                         break;
2397
2398 #if ENABLE_FEATURE_TAB_COMPLETION
2399                 if (ic_raw != '\t')
2400                         lastWasTab = 0;
2401 #endif
2402         } /* while (1) */
2403
2404 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
2405         if (S.sent_ESC_br6n) {
2406                 /* "sleep 1; busybox ash" + hold [Enter] to trigger.
2407                  * We sent "ESC [ 6 n", but got '\n' first, and
2408                  * KEYCODE_CURSOR_POS response is now buffered from terminal.
2409                  * It's bad already and not much can be done with it
2410                  * (it _will_ be visible for the next process to read stdin),
2411                  * but without this delay it even shows up on the screen
2412                  * as garbage because we restore echo settings with tcsetattr
2413                  * before it comes in. UGLY!
2414                  */
2415                 usleep(20*1000);
2416         }
2417 #endif
2418
2419 /* End of bug-catching "command_must_not_be_used" trick */
2420 #undef command
2421
2422 #if ENABLE_UNICODE_SUPPORT
2423         command[0] = '\0';
2424         if (command_len > 0)
2425                 command_len = save_string(command, maxsize - 1);
2426         free(command_ps);
2427 #endif
2428
2429         if (command_len > 0)
2430                 remember_in_history(command);
2431
2432         if (break_out > 0) {
2433                 command[command_len++] = '\n';
2434                 command[command_len] = '\0';
2435         }
2436
2437 #if ENABLE_FEATURE_TAB_COMPLETION
2438         free_tab_completion_data();
2439 #endif
2440
2441         /* restore initial_settings */
2442         tcsetattr_stdin_TCSANOW(&initial_settings);
2443         /* restore SIGWINCH handler */
2444         signal(SIGWINCH, previous_SIGWINCH_handler);
2445         fflush_all();
2446
2447         len = command_len;
2448         DEINIT_S();
2449
2450         return len; /* can't return command_len, DEINIT_S() destroys it */
2451 }
2452
2453 #else  /* !FEATURE_EDITING */
2454
2455 #undef read_line_input
2456 int FAST_FUNC read_line_input(const char* prompt, char* command, int maxsize)
2457 {
2458         fputs(prompt, stdout);
2459         fflush_all();
2460         fgets(command, maxsize, stdin);
2461         return strlen(command);
2462 }
2463
2464 #endif  /* !FEATURE_EDITING */
2465
2466
2467 /*
2468  * Testing
2469  */
2470
2471 #ifdef TEST
2472
2473 #include <locale.h>
2474
2475 const char *applet_name = "debug stuff usage";
2476
2477 int main(int argc, char **argv)
2478 {
2479         char buff[MAX_LINELEN];
2480         char *prompt =
2481 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
2482                 "\\[\\033[32;1m\\]\\u@\\[\\x1b[33;1m\\]\\h:"
2483                 "\\[\\033[34;1m\\]\\w\\[\\033[35;1m\\] "
2484                 "\\!\\[\\e[36;1m\\]\\$ \\[\\E[0m\\]";
2485 #else
2486                 "% ";
2487 #endif
2488
2489         while (1) {
2490                 int l;
2491                 l = read_line_input(prompt, buff);
2492                 if (l <= 0 || buff[l-1] != '\n')
2493                         break;
2494                 buff[l-1] = '\0';
2495                 printf("*** read_line_input() returned line =%s=\n", buff);
2496         }
2497         printf("*** read_line_input() detect ^D\n");
2498         return 0;
2499 }
2500
2501 #endif  /* TEST */