libbb/lineedit.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Termios command line History and 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 SEQ_CLEAR_TILL_END_OF_SCREEN "\033[J"
  98 //#define SEQ_CLEAR_TILL_END_OF_LINE   "\033[K"
  99
 100
 101 enum {
 102         /* We use int16_t for positions, need to limit line len */
 103         MAX_LINELEN = CONFIG_FEATURE_EDITING_MAX_LEN < 0x7ff0
 104                       ? CONFIG_FEATURE_EDITING_MAX_LEN
 105                       : 0x7ff0
 106 };
 107
 108 #if ENABLE_USERNAME_OR_HOMEDIR
 109 static const char null_str[] ALIGN1 = "";
 110 #endif
 111
 112 /* We try to minimize both static and stack usage. */
 113 struct lineedit_statics {
 114         line_input_t *state;
 115
 116         volatile unsigned cmdedit_termw; /* = 80; */ /* actual terminal width */
 117         sighandler_t previous_SIGWINCH_handler;
 118
 119         unsigned cmdedit_x;        /* real x (col) terminal position */
 120         unsigned cmdedit_y;        /* pseudoreal y (row) terminal position */
 121         unsigned cmdedit_prmt_len; /* length of prompt (without colors etc) */
 122
 123         unsigned cursor;
 124         int command_len; /* must be signed */
 125         /* signed maxsize: we want x in "if (x > S.maxsize)"
 126          * to _not_ be promoted to unsigned */
 127         int maxsize;
 128         CHAR_T *command_ps;
 129
 130         const char *cmdedit_prompt;
 131 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
 132         int num_ok_lines; /* = 1; */
 133 #endif
 134
 135 #if ENABLE_USERNAME_OR_HOMEDIR
 136         char *user_buf;
 137         char *home_pwd_buf; /* = (char*)null_str; */
 138 #endif
 139
 140 #if ENABLE_FEATURE_TAB_COMPLETION
 141         char **matches;
 142         unsigned num_matches;
 143 #endif
 144
 145 #if ENABLE_FEATURE_EDITING_VI
 146 # define DELBUFSIZ 128
 147         CHAR_T *delptr;
 148         smallint newdelflag;     /* whether delbuf should be reused yet */
 149         CHAR_T delbuf[DELBUFSIZ];  /* a place to store deleted characters */
 150 #endif
 151 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
 152         smallint sent_ESC_br6n;
 153 #endif
 154
 155         /* Formerly these were big buffers on stack: */
 156 #if ENABLE_FEATURE_TAB_COMPLETION
 157         char input_tab__matchBuf[MAX_LINELEN];
 158         int16_t find_match__int_buf[MAX_LINELEN + 1]; /* need to have 9 bits at least */
 159         int16_t find_match__pos_buf[MAX_LINELEN + 1];
 160 #endif
 161 };
 162
 163 /* See lineedit_ptr_hack.c */
 164 extern struct lineedit_statics *const lineedit_ptr_to_statics;
 165
 166 #define S (*lineedit_ptr_to_statics)
 167 #define state            (S.state           )
 168 #define cmdedit_termw    (S.cmdedit_termw   )
 169 #define previous_SIGWINCH_handler (S.previous_SIGWINCH_handler)
 170 #define cmdedit_x        (S.cmdedit_x       )
 171 #define cmdedit_y        (S.cmdedit_y       )
 172 #define cmdedit_prmt_len (S.cmdedit_prmt_len)
 173 #define cursor           (S.cursor          )
 174 #define command_len      (S.command_len     )
 175 #define command_ps       (S.command_ps      )
 176 #define cmdedit_prompt   (S.cmdedit_prompt  )
 177 #define num_ok_lines     (S.num_ok_lines    )
 178 #define user_buf         (S.user_buf        )
 179 #define home_pwd_buf     (S.home_pwd_buf    )
 180 #define matches          (S.matches         )
 181 #define num_matches      (S.num_matches     )
 182 #define delptr           (S.delptr          )
 183 #define newdelflag       (S.newdelflag      )
 184 #define delbuf           (S.delbuf          )
 185
 186 #define INIT_S() do { \
 187         (*(struct lineedit_statics**)&lineedit_ptr_to_statics) = xzalloc(sizeof(S)); \
 188         barrier(); \
 189         cmdedit_termw = 80; \
 190         IF_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines = 1;) \
 191         IF_USERNAME_OR_HOMEDIR(home_pwd_buf = (char*)null_str;) \
 192 } while (0)
 193 static void deinit_S(void)
 194 {
 195 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
 196         /* This one is allocated only if FANCY_PROMPT is on
 197          * (otherwise it points to verbatim prompt (NOT malloced) */
 198         free((char*)cmdedit_prompt);
 199 #endif
 200 #if ENABLE_USERNAME_OR_HOMEDIR
 201         free(user_buf);
 202         if (home_pwd_buf != null_str)
 203                 free(home_pwd_buf);
 204 #endif
 205         free(lineedit_ptr_to_statics);
 206 }
 207 #define DEINIT_S() deinit_S()
 208
 209
 210 #if ENABLE_UNICODE_SUPPORT
 211 static size_t load_string(const char *src, int maxsize)
 212 {
 213         ssize_t len = mbstowcs(command_ps, src, maxsize - 1);
 214         if (len < 0)
 215                 len = 0;
 216         command_ps[len] = 0;
 217         return len;
 218 }
 219 static unsigned save_string(char *dst, unsigned maxsize)
 220 {
 221 # if !ENABLE_UNICODE_PRESERVE_BROKEN
 222         ssize_t len = wcstombs(dst, command_ps, maxsize - 1);
 223         if (len < 0)
 224                 len = 0;
 225         dst[len] = '\0';
 226         return len;
 227 # else
 228         unsigned dstpos = 0;
 229         unsigned srcpos = 0;
 230
 231         maxsize--;
 232         while (dstpos < maxsize) {
 233                 wchar_t wc;
 234                 int n = srcpos;
 235
 236                 /* Convert up to 1st invalid byte (or up to end) */
 237                 while ((wc = command_ps[srcpos]) != 0
 238                     && !unicode_is_raw_byte(wc)
 239                 ) {
 240                         srcpos++;
 241                 }
 242                 command_ps[srcpos] = 0;
 243                 n = wcstombs(dst + dstpos, command_ps + n, maxsize - dstpos);
 244                 if (n < 0) /* should not happen */
 245                         break;
 246                 dstpos += n;
 247                 if (wc == 0) /* usually is */
 248                         break;
 249
 250                 /* We do have invalid byte here! */
 251                 command_ps[srcpos] = wc; /* restore it */
 252                 srcpos++;
 253                 if (dstpos == maxsize)
 254                         break;
 255                 dst[dstpos++] = (char) wc;
 256         }
 257         dst[dstpos] = '\0';
 258         return dstpos;
 259 # endif
 260 }
 261 /* I thought just fputwc(c, stdout) would work. But no... */
 262 static void BB_PUTCHAR(wchar_t c)
 263 {
 264         char buf[MB_CUR_MAX + 1];
 265         mbstate_t mbst = { 0 };
 266         ssize_t len;
 267
 268         len = wcrtomb(buf, c, &mbst);
 269         if (len > 0) {
 270                 buf[len] = '\0';
 271                 fputs(buf, stdout);
 272         }
 273 }
 274 # if ENABLE_UNICODE_COMBINING_WCHARS || ENABLE_UNICODE_WIDE_WCHARS
 275 static wchar_t adjust_width_and_validate_wc(unsigned *width_adj, wchar_t wc)
 276 # else
 277 static wchar_t adjust_width_and_validate_wc(wchar_t wc)
 278 #  define adjust_width_and_validate_wc(width_adj, wc) \
 279         ((*(width_adj))++, adjust_width_and_validate_wc(wc))
 280 # endif
 281 {
 282         int w = 1;
 283
 284         if (unicode_status == UNICODE_ON) {
 285                 if (wc > CONFIG_LAST_SUPPORTED_WCHAR) {
 286                         /* note: also true for unicode_is_raw_byte(wc) */
 287                         goto subst;
 288                 }
 289                 w = wcwidth(wc);
 290                 if ((ENABLE_UNICODE_COMBINING_WCHARS && w < 0)
 291                  || (!ENABLE_UNICODE_COMBINING_WCHARS && w <= 0)
 292                  || (!ENABLE_UNICODE_WIDE_WCHARS && w > 1)
 293                 ) {
 294  subst:
 295                         w = 1;
 296                         wc = CONFIG_SUBST_WCHAR;
 297                 }
 298         }
 299
 300 # if ENABLE_UNICODE_COMBINING_WCHARS || ENABLE_UNICODE_WIDE_WCHARS
 301         *width_adj += w;
 302 #endif
 303         return wc;
 304 }
 305 #else /* !UNICODE */
 306 static size_t load_string(const char *src, int maxsize)
 307 {
 308         safe_strncpy(command_ps, src, maxsize);
 309         return strlen(command_ps);
 310 }
 311 # if ENABLE_FEATURE_TAB_COMPLETION
 312 static void save_string(char *dst, unsigned maxsize)
 313 {
 314         safe_strncpy(dst, command_ps, maxsize);
 315 }
 316 # endif
 317 # define BB_PUTCHAR(c) bb_putchar(c)
 318 /* Should never be called: */
 319 int adjust_width_and_validate_wc(unsigned *width_adj, int wc);
 320 #endif
 321
 322
 323 /* Put 'command_ps[cursor]', cursor++.
 324  * Advance cursor on screen. If we reached right margin, scroll text up
 325  * and remove terminal margin effect by printing 'next_char' */
 326 #define HACK_FOR_WRONG_WIDTH 1
 327 static void put_cur_glyph_and_inc_cursor(void)
 328 {
 329         CHAR_T c = command_ps[cursor];
 330         unsigned width = 0;
 331         int ofs_to_right;
 332
 333         if (c == BB_NUL) {
 334                 /* erase character after end of input string */
 335                 c = ' ';
 336         } else {
 337                 /* advance cursor only if we aren't at the end yet */
 338                 cursor++;
 339                 if (unicode_status == UNICODE_ON) {
 340                         IF_UNICODE_WIDE_WCHARS(width = cmdedit_x;)
 341                         c = adjust_width_and_validate_wc(&cmdedit_x, c);
 342                         IF_UNICODE_WIDE_WCHARS(width = cmdedit_x - width;)
 343                 } else {
 344                         cmdedit_x++;
 345                 }
 346         }
 347
 348         ofs_to_right = cmdedit_x - cmdedit_termw;
 349         if (!ENABLE_UNICODE_WIDE_WCHARS || ofs_to_right <= 0) {
 350                 /* c fits on this line */
 351                 BB_PUTCHAR(c);
 352         }
 353
 354         if (ofs_to_right >= 0) {
 355                 /* we go to the next line */
 356 #if HACK_FOR_WRONG_WIDTH
 357                 /* This works better if our idea of term width is wrong
 358                  * and it is actually wider (often happens on serial lines).
 359                  * Printing CR,LF *forces* cursor to next line.
 360                  * OTOH if terminal width is correct AND terminal does NOT
 361                  * have automargin (IOW: it is moving cursor to next line
 362                  * by itself (which is wrong for VT-10x terminals)),
 363                  * this will break things: there will be one extra empty line */
 364                 puts("\r"); /* + implicit '\n' */
 365 #else
 366                 /* VT-10x terminals don't wrap cursor to next line when last char
 367                  * on the line is printed - cursor stays "over" this char.
 368                  * Need to print _next_ char too (first one to appear on next line)
 369                  * to make cursor move down to next line.
 370                  */
 371                 /* Works ok only if cmdedit_termw is correct. */
 372                 c = command_ps[cursor];
 373                 if (c == BB_NUL)
 374                         c = ' ';
 375                 BB_PUTCHAR(c);
 376                 bb_putchar('\b');
 377 #endif
 378                 cmdedit_y++;
 379                 if (!ENABLE_UNICODE_WIDE_WCHARS || ofs_to_right == 0) {
 380                         width = 0;
 381                 } else { /* ofs_to_right > 0 */
 382                         /* wide char c didn't fit on prev line */
 383                         BB_PUTCHAR(c);
 384                 }
 385                 cmdedit_x = width;
 386         }
 387 }
 388
 389 /* Move to end of line (by printing all chars till the end) */
 390 static void put_till_end_and_adv_cursor(void)
 391 {
 392         while (cursor < command_len)
 393                 put_cur_glyph_and_inc_cursor();
 394 }
 395
 396 /* Go to the next line */
 397 static void goto_new_line(void)
 398 {
 399         put_till_end_and_adv_cursor();
 400         if (cmdedit_x != 0)
 401                 bb_putchar('\n');
 402 }
 403
 404 static void beep(void)
 405 {
 406         bb_putchar('\007');
 407 }
 408
 409 static void put_prompt(void)
 410 {
 411         unsigned w;
 412
 413         fputs(cmdedit_prompt, stdout);
 414         fflush_all();
 415         cursor = 0;
 416         w = cmdedit_termw; /* read volatile var once */
 417         cmdedit_y = cmdedit_prmt_len / w; /* new quasireal y */
 418         cmdedit_x = cmdedit_prmt_len % w;
 419 }
 420
 421 /* Move back one character */
 422 /* (optimized for slow terminals) */
 423 static void input_backward(unsigned num)
 424 {
 425         if (num > cursor)
 426                 num = cursor;
 427         if (num == 0)
 428                 return;
 429         cursor -= num;
 430
 431         if ((ENABLE_UNICODE_COMBINING_WCHARS || ENABLE_UNICODE_WIDE_WCHARS)
 432          && unicode_status == UNICODE_ON
 433         ) {
 434                 /* correct NUM to be equal to _screen_ width */
 435                 int n = num;
 436                 num = 0;
 437                 while (--n >= 0)
 438                         adjust_width_and_validate_wc(&num, command_ps[cursor + n]);
 439                 if (num == 0)
 440                         return;
 441         }
 442
 443         if (cmdedit_x >= num) {
 444                 cmdedit_x -= num;
 445                 if (num <= 4) {
 446                         /* This is longer by 5 bytes on x86.
 447                          * Also gets miscompiled for ARM users
 448                          * (busybox.net/bugs/view.php?id=2274).
 449                          * printf(("\b\b\b\b" + 4) - num);
 450                          * return;
 451                          */
 452                         do {
 453                                 bb_putchar('\b');
 454                         } while (--num);
 455                         return;
 456                 }
 457                 printf("\033[%uD", num);
 458                 return;
 459         }
 460
 461         /* Need to go one or more lines up */
 462         if (ENABLE_UNICODE_WIDE_WCHARS) {
 463                 /* With wide chars, it is hard to "backtrack"
 464                  * and reliably figure out where to put cursor.
 465                  * Example (<> is a wide char; # is an ordinary char, _ cursor):
 466                  * |prompt: <><> |
 467                  * |<><><><><><> |
 468                  * |_            |
 469                  * and user presses left arrow. num = 1, cmdedit_x = 0,
 470                  * We need to go up one line, and then - how do we know that
 471                  * we need to go *10* positions to the right? Because
 472                  * |prompt: <>#<>|
 473                  * |<><><>#<><><>|
 474                  * |_            |
 475                  * in this situation we need to go *11* positions to the right.
 476                  *
 477                  * A simpler thing to do is to redraw everything from the start
 478                  * up to new cursor position (which is already known):
 479                  */
 480                 unsigned sv_cursor;
 481                 /* go to 1st column; go up to first line */
 482                 printf("\r" "\033[%uA", cmdedit_y);
 483                 cmdedit_y = 0;
 484                 sv_cursor = cursor;
 485                 put_prompt(); /* sets cursor to 0 */
 486                 while (cursor < sv_cursor)
 487                         put_cur_glyph_and_inc_cursor();
 488         } else {
 489                 int lines_up;
 490                 unsigned width;
 491                 /* num = chars to go back from the beginning of current line: */
 492                 num -= cmdedit_x;
 493                 width = cmdedit_termw; /* read volatile var once */
 494                 /* num=1...w: one line up, w+1...2w: two, etc: */
 495                 lines_up = 1 + (num - 1) / width;
 496                 cmdedit_x = (width * cmdedit_y - num) % width;
 497                 cmdedit_y -= lines_up;
 498                 /* go to 1st column; go up */
 499                 printf("\r" "\033[%uA", lines_up);
 500                 /* go to correct column.
 501                  * xterm, konsole, Linux VT interpret 0 as 1 below! wow.
 502                  * need to *make sure* we skip it if cmdedit_x == 0 */
 503                 if (cmdedit_x)
 504                         printf("\033[%uC", cmdedit_x);
 505         }
 506 }
 507
 508 /* draw prompt, editor line, and clear tail */
 509 static void redraw(int y, int back_cursor)
 510 {
 511         if (y > 0) /* up y lines */
 512                 printf("\033[%uA", y);
 513         bb_putchar('\r');
 514         put_prompt();
 515         put_till_end_and_adv_cursor();
 516         printf(SEQ_CLEAR_TILL_END_OF_SCREEN);
 517         input_backward(back_cursor);
 518 }
 519
 520 /* Delete the char in front of the cursor, optionally saving it
 521  * for later putback */
 522 #if !ENABLE_FEATURE_EDITING_VI
 523 static void input_delete(void)
 524 #define input_delete(save) input_delete()
 525 #else
 526 static void input_delete(int save)
 527 #endif
 528 {
 529         int j = cursor;
 530
 531         if (j == (int)command_len)
 532                 return;
 533
 534 #if ENABLE_FEATURE_EDITING_VI
 535         if (save) {
 536                 if (newdelflag) {
 537                         delptr = delbuf;
 538                         newdelflag = 0;
 539                 }
 540                 if ((delptr - delbuf) < DELBUFSIZ)
 541                         *delptr++ = command_ps[j];
 542         }
 543 #endif
 544
 545         memmove(command_ps + j, command_ps + j + 1,
 546                         /* (command_len + 1 [because of NUL]) - (j + 1)
 547                          * simplified into (command_len - j) */
 548                         (command_len - j) * sizeof(command_ps[0]));
 549         command_len--;
 550         put_till_end_and_adv_cursor();
 551         /* Last char is still visible, erase it (and more) */
 552         printf(SEQ_CLEAR_TILL_END_OF_SCREEN);
 553         input_backward(cursor - j);     /* back to old pos cursor */
 554 }
 555
 556 #if ENABLE_FEATURE_EDITING_VI
 557 static void put(void)
 558 {
 559         int ocursor;
 560         int j = delptr - delbuf;
 561
 562         if (j == 0)
 563                 return;
 564         ocursor = cursor;
 565         /* open hole and then fill it */
 566         memmove(command_ps + cursor + j, command_ps + cursor,
 567                         (command_len - cursor + 1) * sizeof(command_ps[0]));
 568         memcpy(command_ps + cursor, delbuf, j * sizeof(command_ps[0]));
 569         command_len += j;
 570         put_till_end_and_adv_cursor();
 571         input_backward(cursor - ocursor - j + 1); /* at end of new text */
 572 }
 573 #endif
 574
 575 /* Delete the char in back of the cursor */
 576 static void input_backspace(void)
 577 {
 578         if (cursor > 0) {
 579                 input_backward(1);
 580                 input_delete(0);
 581         }
 582 }
 583
 584 /* Move forward one character */
 585 static void input_forward(void)
 586 {
 587         if (cursor < command_len)
 588                 put_cur_glyph_and_inc_cursor();
 589 }
 590
 591 #if ENABLE_FEATURE_TAB_COMPLETION
 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 static NOINLINE void username_completion(const char *ud)
 643 {
 644         /* Using _r function to avoid pulling in static buffers */
 645         char line_buff[256];
 646         struct passwd pwd;
 647         struct passwd *result;
 648         int userlen;
 649
 650         ud++; /* skip ~ */
 651         userlen = strlen(ud);
 652
 653         setpwent();
 654         while (!getpwent_r(&pwd, line_buff, sizeof(line_buff), &result)) {
 655                 /* Null usernames should result in all users as possible completions. */
 656                 if (/*!userlen || */ strncmp(ud, pwd.pw_name, userlen) == 0) {
 657                         add_match(xasprintf("~%s/", pwd.pw_name));
 658                 }
 659         }
 660         endpwent();
 661 }
 662 #endif  /* FEATURE_COMMAND_USERNAME_COMPLETION */
 663
 664 enum {
 665         FIND_EXE_ONLY = 0,
 666         FIND_DIR_ONLY = 1,
 667         FIND_FILE_ONLY = 2,
 668 };
 669
 670 static int path_parse(char ***p)
 671 {
 672         int npth;
 673         const char *pth;
 674         char *tmp;
 675         char **res;
 676
 677         if (state->flags & WITH_PATH_LOOKUP)
 678                 pth = state->path_lookup;
 679         else
 680                 pth = getenv("PATH");
 681
 682         /* PATH="" or PATH=":"? */
 683         if (!pth || !pth[0] || LONE_CHAR(pth, ':'))
 684                 return 1;
 685
 686         tmp = (char*)pth;
 687         npth = 1; /* path component count */
 688         while (1) {
 689                 tmp = strchr(tmp, ':');
 690                 if (!tmp)
 691                         break;
 692                 tmp++;
 693                 if (*tmp == '\0')
 694                         break;  /* :<empty> */
 695                 npth++;
 696         }
 697
 698         *p = res = xmalloc(npth * sizeof(res[0]));
 699         res[0] = tmp = xstrdup(pth);
 700         npth = 1;
 701         while (1) {
 702                 tmp = strchr(tmp, ':');
 703                 if (!tmp)
 704                         break;
 705                 *tmp++ = '\0'; /* ':' -> '\0' */
 706                 if (*tmp == '\0')
 707                         break; /* :<empty> */
 708                 res[npth++] = tmp;
 709         }
 710         return npth;
 711 }
 712
 713 static void exe_n_cwd_tab_completion(char *command, int type)
 714 {
 715         char *path1[1];
 716         char **paths = path1;
 717         int npaths;
 718         int i;
 719         char *pfind;
 720         char *dirbuf = NULL;
 721
 722         npaths = 1;
 723         path1[0] = (char*)".";
 724
 725         pfind = strrchr(command, '/');
 726         if (!pfind) {
 727                 if (type == FIND_EXE_ONLY)
 728                         npaths = path_parse(&paths);
 729                 pfind = command;
 730         } else {
 731                 /* point to 'l' in "..../last_component" */
 732                 pfind++;
 733                 /* dirbuf = ".../.../.../" */
 734                 dirbuf = xstrndup(command, pfind - command);
 735 #if ENABLE_FEATURE_USERNAME_COMPLETION
 736                 if (dirbuf[0] == '~')   /* ~/... or ~user/... */
 737                         dirbuf = username_path_completion(dirbuf);
 738 #endif
 739                 path1[0] = dirbuf;
 740         }
 741
 742         for (i = 0; i < npaths; i++) {
 743                 DIR *dir;
 744                 struct dirent *next;
 745                 struct stat st;
 746                 char *found;
 747
 748                 dir = opendir(paths[i]);
 749                 if (!dir)
 750                         continue; /* don't print an error */
 751
 752                 while ((next = readdir(dir)) != NULL) {
 753                         const char *name_found = next->d_name;
 754
 755                         /* .../<tab>: bash 3.2.0 shows dotfiles, but not . and .. */
 756                         if (!pfind[0] && DOT_OR_DOTDOT(name_found))
 757                                 continue;
 758                         /* match? */
 759                         if (strncmp(name_found, pfind, strlen(pfind)) != 0)
 760                                 continue; /* no */
 761
 762                         found = concat_path_file(paths[i], name_found);
 763                         /* NB: stat() first so that we see is it a directory;
 764                          * but if that fails, use lstat() so that
 765                          * we still match dangling links */
 766                         if (stat(found, &st) && lstat(found, &st))
 767                                 goto cont; /* hmm, remove in progress? */
 768
 769                         /* save only name if we scan PATH */
 770                         if (paths[i] != dirbuf)
 771                                 strcpy(found, name_found);
 772
 773                         if (S_ISDIR(st.st_mode)) {
 774                                 unsigned len1 = strlen(found);
 775                                 /* name is a directory */
 776                                 if (found[len1-1] != '/') {
 777                                         found = xrealloc(found, len1 + 2);
 778                                         found[len1] = '/';
 779                                         found[len1 + 1] = '\0';
 780                                 }
 781                         } else {
 782                                 /* skip files if looking for dirs only (example: cd) */
 783                                 if (type == FIND_DIR_ONLY)
 784                                         goto cont;
 785                         }
 786                         /* add it to the list */
 787                         add_match(found);
 788                         continue;
 789  cont:
 790                         free(found);
 791                 }
 792                 closedir(dir);
 793         } /* for every path */
 794
 795         if (paths != path1) {
 796                 free(paths[0]); /* allocated memory is only in first member */
 797                 free(paths);
 798         }
 799         free(dirbuf);
 800 }
 801
 802 /* QUOT is used on elements of int_buf[], which are bytes,
 803  * not Unicode chars. Therefore it works correctly even in Unicode mode.
 804  */
 805 #define QUOT (UCHAR_MAX+1)
 806
 807 #define int_buf (S.find_match__int_buf)
 808 #define pos_buf (S.find_match__pos_buf)
 809 /* is must be <= in */
 810 static void collapse_pos(int is, int in)
 811 {
 812         memmove(int_buf+is, int_buf+in, (MAX_LINELEN+1-in) * sizeof(int_buf[0]));
 813         memmove(pos_buf+is, pos_buf+in, (MAX_LINELEN+1-in) * sizeof(pos_buf[0]));
 814 }
 815 /* On entry, matchBuf contains everything up to cursor at the moment <tab>
 816  * was pressed. This function looks at it, figures out what part of it
 817  * constitutes the command/file/directory prefix to use for completion,
 818  * and rewrites matchBuf to contain only that part.
 819  */
 820 static NOINLINE int build_match_prefix(char *matchBuf, int *len_with_quotes)
 821 {
 822         int i, j;
 823         int command_mode;
 824         int c, c2;
 825 /*      Were local, but it used too much stack */
 826 /*      int16_t int_buf[MAX_LINELEN + 1]; */
 827 /*      int16_t pos_buf[MAX_LINELEN + 1]; */
 828
 829         /* set to integer dimension characters and own positions */
 830         for (i = 0;; i++) {
 831                 int_buf[i] = (unsigned char)matchBuf[i];
 832                 if (int_buf[i] == 0) {
 833                         pos_buf[i] = -1; /* end-fo-line indicator */
 834                         break;
 835                 }
 836                 pos_buf[i] = i;
 837         }
 838
 839         /* mask \+symbol and convert '\t' to ' ' */
 840         for (i = j = 0; matchBuf[i]; i++, j++) {
 841                 if (matchBuf[i] == '\\') {
 842                         collapse_pos(j, j + 1);
 843                         int_buf[j] |= QUOT;
 844                         i++;
 845                 }
 846         }
 847         /* mask "symbols" or 'symbols' */
 848         c2 = 0;
 849         for (i = 0; int_buf[i]; i++) {
 850                 c = int_buf[i];
 851                 if (c == '\'' || c == '"') {
 852                         if (c2 == 0)
 853                                 c2 = c;
 854                         else {
 855                                 if (c == c2)
 856                                         c2 = 0;
 857                                 else
 858                                         int_buf[i] |= QUOT;
 859                         }
 860                 } else if (c2 != 0 && c != '$')
 861                         int_buf[i] |= QUOT;
 862         }
 863
 864         /* skip commands with arguments if line has commands delimiters */
 865         /* ';' ';;' '&' '|' '&&' '||' but '>&' '<&' '>|' */
 866         for (i = 0; int_buf[i]; i++) {
 867                 int n;
 868                 c = int_buf[i];
 869                 c2 = int_buf[i + 1];
 870                 j = i ? int_buf[i - 1] : -1;
 871                 n = 0;
 872                 if (c == ';' || c == '&' || c == '|') {
 873                         n = 1 + (c == c2);
 874                         if (c == '&') {
 875                                 if (j == '>' || j == '<')
 876                                         n = 0;
 877                         } else if (c == '|' && j == '>')
 878                                 n = 0;
 879                 }
 880                 if (n) {
 881                         collapse_pos(0, i + n);
 882                         i = -1;  /* hack incremet */
 883                 }
 884         }
 885         /* collapse `command...` */
 886         for (i = 0; int_buf[i]; i++) {
 887                 if (int_buf[i] == '`') {
 888                         for (j = i + 1; int_buf[j]; j++)
 889                                 if (int_buf[j] == '`') {
 890                                         collapse_pos(i, j + 1);
 891                                         j = 0;
 892                                         break;
 893                                 }
 894                         if (j) {
 895                                 /* not found closing ` - command mode, collapse all previous */
 896                                 collapse_pos(0, i + 1);
 897                                 break;
 898                         } else
 899                                 i--;  /* hack incremet */
 900                 }
 901         }
 902
 903         /* collapse (command...(command...)...) or {command...{command...}...} */
 904         c = 0;  /* "recursive" level */
 905         c2 = 0;
 906         for (i = 0; int_buf[i]; i++) {
 907                 if (int_buf[i] == '(' || int_buf[i] == '{') {
 908                         if (int_buf[i] == '(')
 909                                 c++;
 910                         else
 911                                 c2++;
 912                         collapse_pos(0, i + 1);
 913                         i = -1;  /* hack incremet */
 914                 }
 915         }
 916         for (i = 0; pos_buf[i] >= 0 && (c > 0 || c2 > 0); i++) {
 917                 if ((int_buf[i] == ')' && c > 0) || (int_buf[i] == '}' && c2 > 0)) {
 918                         if (int_buf[i] == ')')
 919                                 c--;
 920                         else
 921                                 c2--;
 922                         collapse_pos(0, i + 1);
 923                         i = -1;  /* hack incremet */
 924                 }
 925         }
 926
 927         /* skip first not quote space */
 928         for (i = 0; int_buf[i]; i++)
 929                 if (int_buf[i] != ' ')
 930                         break;
 931         if (i)
 932                 collapse_pos(0, i);
 933
 934         /* set find mode for completion */
 935         command_mode = FIND_EXE_ONLY;
 936         for (i = 0; int_buf[i]; i++) {
 937                 if (int_buf[i] == ' ' || int_buf[i] == '<' || int_buf[i] == '>') {
 938                         if (int_buf[i] == ' ' && command_mode == FIND_EXE_ONLY
 939                          && matchBuf[pos_buf[0]] == 'c'
 940                          && matchBuf[pos_buf[1]] == 'd'
 941                         ) {
 942                                 command_mode = FIND_DIR_ONLY;
 943                         } else {
 944                                 command_mode = FIND_FILE_ONLY;
 945                                 break;
 946                         }
 947                 }
 948         }
 949         for (i = 0; int_buf[i]; i++) /* quasi-strlen(int_buf) */
 950                 continue;
 951         /* find last word */
 952         for (--i; i >= 0; i--) {
 953                 c = int_buf[i];
 954                 if (c == ' ' || c == '<' || c == '>' || c == '|' || c == '&') {
 955                         collapse_pos(0, i + 1);
 956                         break;
 957                 }
 958         }
 959         /* skip first not quoted '\'' or '"' */
 960         for (i = 0; int_buf[i] == '\'' || int_buf[i] == '"'; i++)
 961                 continue;
 962         /* collapse quote or unquote // or /~ */
 963         while ((int_buf[i] & ~QUOT) == '/'
 964          && ((int_buf[i+1] & ~QUOT) == '/' || (int_buf[i+1] & ~QUOT) == '~')
 965         ) {
 966                 i++;
 967         }
 968
 969         /* set only match and destroy quotes */
 970         j = 0;
 971         for (c = 0; pos_buf[i] >= 0; i++) {
 972                 matchBuf[c++] = matchBuf[pos_buf[i]];
 973                 j = pos_buf[i] + 1;
 974         }
 975         matchBuf[c] = '\0';
 976         /* old length matchBuf with quotes symbols */
 977         *len_with_quotes = j ? j - pos_buf[0] : 0;
 978
 979         return command_mode;
 980 }
 981 #undef int_buf
 982 #undef pos_buf
 983
 984 /*
 985  * display by column (original idea from ls applet,
 986  * very optimized by me :)
 987  */
 988 static void showfiles(void)
 989 {
 990         int ncols, row;
 991         int column_width = 0;
 992         int nfiles = num_matches;
 993         int nrows = nfiles;
 994         int l;
 995
 996         /* find the longest file name - use that as the column width */
 997         for (row = 0; row < nrows; row++) {
 998                 l = unicode_strwidth(matches[row]);
 999                 if (column_width < l)
1000                         column_width = l;
1001         }
1002         column_width += 2;              /* min space for columns */
1003         ncols = cmdedit_termw / column_width;
1004
1005         if (ncols > 1) {
1006                 nrows /= ncols;
1007                 if (nfiles % ncols)
1008                         nrows++;        /* round up fractionals */
1009         } else {
1010                 ncols = 1;
1011         }
1012         for (row = 0; row < nrows; row++) {
1013                 int n = row;
1014                 int nc;
1015
1016                 for (nc = 1; nc < ncols && n+nrows < nfiles; n += nrows, nc++) {
1017                         printf("%s%-*s", matches[n],
1018                                 (int)(column_width - unicode_strwidth(matches[n])), ""
1019                         );
1020                 }
1021                 if (ENABLE_UNICODE_SUPPORT)
1022                         puts(printable_string(NULL, matches[n]));
1023                 else
1024                         puts(matches[n]);
1025         }
1026 }
1027
1028 static char *add_quote_for_spec_chars(char *found)
1029 {
1030         int l = 0;
1031         char *s = xzalloc((strlen(found) + 1) * 2);
1032
1033         while (*found) {
1034                 if (strchr(" `\"#$%^&*()=+{}[]:;'|\\<>", *found))
1035                         s[l++] = '\\';
1036                 s[l++] = *found++;
1037         }
1038         /* s[l] = '\0'; - already is */
1039         return s;
1040 }
1041
1042 /* Do TAB completion */
1043 static void input_tab(smallint *lastWasTab)
1044 {
1045         if (!(state->flags & TAB_COMPLETION))
1046                 return;
1047
1048         if (!*lastWasTab) {
1049                 char *tmp, *tmp1;
1050                 size_t len_found;
1051 /*              char matchBuf[MAX_LINELEN]; */
1052 #define matchBuf (S.input_tab__matchBuf)
1053                 int find_type;
1054                 int recalc_pos;
1055 #if ENABLE_UNICODE_SUPPORT
1056                 /* cursor pos in command converted to multibyte form */
1057                 int cursor_mb;
1058 #endif
1059
1060                 *lastWasTab = TRUE;             /* flop trigger */
1061
1062                 /* Make a local copy of the string --
1063                  * up to the position of the cursor */
1064 #if !ENABLE_UNICODE_SUPPORT
1065                 save_string(matchBuf, cursor + 1);
1066 #else
1067                 {
1068                         CHAR_T wc = command_ps[cursor];
1069                         command_ps[cursor] = 0;
1070                         save_string(matchBuf, MAX_LINELEN);
1071                         command_ps[cursor] = wc;
1072                         cursor_mb = strlen(matchBuf);
1073                 }
1074 #endif
1075                 tmp = matchBuf;
1076
1077                 find_type = build_match_prefix(matchBuf, &recalc_pos);
1078
1079                 /* Free up any memory already allocated */
1080                 free_tab_completion_data();
1081
1082 #if ENABLE_FEATURE_USERNAME_COMPLETION
1083                 /* If the word starts with `~' and there is no slash in the word,
1084                  * then try completing this word as a username. */
1085                 if (state->flags & USERNAME_COMPLETION)
1086                         if (matchBuf[0] == '~' && strchr(matchBuf, '/') == NULL)
1087                                 username_completion(matchBuf);
1088 #endif
1089                 /* Try to match any executable in our path and everything
1090                  * in the current working directory */
1091                 if (!matches)
1092                         exe_n_cwd_tab_completion(matchBuf, find_type);
1093                 /* Sort, then remove any duplicates found */
1094                 if (matches) {
1095                         unsigned i;
1096                         unsigned n = 0;
1097                         qsort_string_vector(matches, num_matches);
1098                         for (i = 0; i < num_matches - 1; ++i) {
1099                                 if (matches[i] && matches[i+1]) { /* paranoia */
1100                                         if (strcmp(matches[i], matches[i+1]) == 0) {
1101                                                 free(matches[i]);
1102                                                 matches[i] = NULL; /* paranoia */
1103                                         } else {
1104                                                 matches[n++] = matches[i];
1105                                         }
1106                                 }
1107                         }
1108                         matches[n++] = matches[i];
1109                         num_matches = n;
1110                 }
1111                 /* Did we find exactly one match? */
1112                 if (num_matches != 1) { /* no */
1113                         beep();
1114                         if (!matches)
1115                                 return; /* no matches at all */
1116                         /* find minimal match */
1117                         tmp1 = xstrdup(matches[0]);
1118                         for (tmp = tmp1; *tmp; tmp++) {
1119                                 for (len_found = 1; len_found < num_matches; len_found++) {
1120                                         if (matches[len_found][tmp - tmp1] != *tmp) {
1121                                                 *tmp = '\0';
1122                                                 break;
1123                                         }
1124                                 }
1125                         }
1126                         if (*tmp1 == '\0') { /* have unique pfx? */
1127                                 free(tmp1); /* no */
1128                                 return;
1129                         }
1130                         tmp = add_quote_for_spec_chars(tmp1);
1131                         free(tmp1);
1132                         len_found = strlen(tmp);
1133                 } else {                        /* exactly one match */
1134                         tmp = add_quote_for_spec_chars(matches[0]);
1135                         /* for next completion current found */
1136                         *lastWasTab = FALSE;
1137
1138                         len_found = strlen(tmp);
1139                         if (tmp[len_found-1] != '/') {
1140                                 tmp[len_found] = ' ';
1141                                 tmp[++len_found] = '\0';
1142                         }
1143                 }
1144
1145 #if !ENABLE_UNICODE_SUPPORT
1146                 /* have space to place the match? */
1147                 /* The result consists of three parts with these lengths: */
1148                 /* (cursor - recalc_pos) + len_found + (command_len - cursor) */
1149                 /* it simplifies into: */
1150                 if ((int)(len_found + command_len - recalc_pos) < S.maxsize) {
1151                         /* save tail */
1152                         strcpy(matchBuf, command_ps + cursor);
1153                         /* add match and tail */
1154                         sprintf(&command_ps[cursor - recalc_pos], "%s%s", tmp, matchBuf);
1155                         command_len = strlen(command_ps);
1156                         /* new pos */
1157                         recalc_pos = cursor - recalc_pos + len_found;
1158                         /* write out the matched command */
1159                         redraw(cmdedit_y, command_len - recalc_pos);
1160                 }
1161 #else
1162                 {
1163                         char command[MAX_LINELEN];
1164                         int len = save_string(command, sizeof(command));
1165                         /* have space to place the match? */
1166                         /* (cursor_mb - recalc_pos) + len_found + (len - cursor_mb) */
1167                         if ((int)(len_found + len - recalc_pos) < MAX_LINELEN) {
1168                                 /* save tail */
1169                                 strcpy(matchBuf, command + cursor_mb);
1170                                 /* where do we want to have cursor after all? */
1171                                 strcpy(&command[cursor_mb - recalc_pos], tmp);
1172                                 len = load_string(command, S.maxsize);
1173                                 /* add match and tail */
1174                                 sprintf(&command[cursor_mb - recalc_pos], "%s%s", tmp, matchBuf);
1175                                 command_len = load_string(command, S.maxsize);
1176                                 /* write out the matched command */
1177                                 /* paranoia: load_string can return 0 on conv error,
1178                                  * prevent passing len = (0 - 12) to redraw */
1179                                 len = command_len - len;
1180                                 redraw(cmdedit_y, len >= 0 ? len : 0);
1181                         }
1182                 }
1183 #endif
1184                 free(tmp);
1185 #undef matchBuf
1186         } else {
1187                 /* Ok -- the last char was a TAB.  Since they
1188                  * just hit TAB again, print a list of all the
1189                  * available choices... */
1190                 if (matches && num_matches > 0) {
1191                         /* changed by goto_new_line() */
1192                         int sav_cursor = cursor;
1193
1194                         /* Go to the next line */
1195                         goto_new_line();
1196                         showfiles();
1197                         redraw(0, command_len - sav_cursor);
1198                 }
1199         }
1200 }
1201
1202 #endif  /* FEATURE_COMMAND_TAB_COMPLETION */
1203
1204
1205 line_input_t* FAST_FUNC new_line_input_t(int flags)
1206 {
1207         line_input_t *n = xzalloc(sizeof(*n));
1208         n->flags = flags;
1209         return n;
1210 }
1211
1212
1213 #if MAX_HISTORY > 0
1214
1215 static void save_command_ps_at_cur_history(void)
1216 {
1217         if (command_ps[0] != BB_NUL) {
1218                 int cur = state->cur_history;
1219                 free(state->history[cur]);
1220
1221 # if ENABLE_UNICODE_SUPPORT
1222                 {
1223                         char tbuf[MAX_LINELEN];
1224                         save_string(tbuf, sizeof(tbuf));
1225                         state->history[cur] = xstrdup(tbuf);
1226                 }
1227 # else
1228                 state->history[cur] = xstrdup(command_ps);
1229 # endif
1230         }
1231 }
1232
1233 /* state->flags is already checked to be nonzero */
1234 static int get_previous_history(void)
1235 {
1236         if ((state->flags & DO_HISTORY) && state->cur_history) {
1237                 save_command_ps_at_cur_history();
1238                 state->cur_history--;
1239                 return 1;
1240         }
1241         beep();
1242         return 0;
1243 }
1244
1245 static int get_next_history(void)
1246 {
1247         if (state->flags & DO_HISTORY) {
1248                 if (state->cur_history < state->cnt_history) {
1249                         save_command_ps_at_cur_history(); /* save the current history line */
1250                         return ++state->cur_history;
1251                 }
1252         }
1253         beep();
1254         return 0;
1255 }
1256
1257 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
1258 /* We try to ensure that concurrent additions to the history
1259  * do not overwrite each other.
1260  * Otherwise shell users get unhappy.
1261  *
1262  * History file is trimmed lazily, when it grows several times longer
1263  * than configured MAX_HISTORY lines.
1264  */
1265
1266 static void free_line_input_t(line_input_t *n)
1267 {
1268         int i = n->cnt_history;
1269         while (i > 0)
1270                 free(n->history[--i]);
1271         free(n);
1272 }
1273
1274 /* state->flags is already checked to be nonzero */
1275 static void load_history(line_input_t *st_parm)
1276 {
1277         char *temp_h[MAX_HISTORY];
1278         char *line;
1279         FILE *fp;
1280         unsigned idx, i, line_len;
1281
1282         /* NB: do not trash old history if file can't be opened */
1283
1284         fp = fopen_for_read(st_parm->hist_file);
1285         if (fp) {
1286                 /* clean up old history */
1287                 for (idx = st_parm->cnt_history; idx > 0;) {
1288                         idx--;
1289                         free(st_parm->history[idx]);
1290                         st_parm->history[idx] = NULL;
1291                 }
1292
1293                 /* fill temp_h[], retaining only last MAX_HISTORY lines */
1294                 memset(temp_h, 0, sizeof(temp_h));
1295                 st_parm->cnt_history_in_file = idx = 0;
1296                 while ((line = xmalloc_fgetline(fp)) != NULL) {
1297                         if (line[0] == '\0') {
1298                                 free(line);
1299                                 continue;
1300                         }
1301                         free(temp_h[idx]);
1302                         temp_h[idx] = line;
1303                         st_parm->cnt_history_in_file++;
1304                         idx++;
1305                         if (idx == MAX_HISTORY)
1306                                 idx = 0;
1307                 }
1308                 fclose(fp);
1309
1310                 /* find first non-NULL temp_h[], if any */
1311                 if (st_parm->cnt_history_in_file) {
1312                         while (temp_h[idx] == NULL) {
1313                                 idx++;
1314                                 if (idx == MAX_HISTORY)
1315                                         idx = 0;
1316                         }
1317                 }
1318
1319                 /* copy temp_h[] to st_parm->history[] */
1320                 for (i = 0; i < MAX_HISTORY;) {
1321                         line = temp_h[idx];
1322                         if (!line)
1323                                 break;
1324                         idx++;
1325                         if (idx == MAX_HISTORY)
1326                                 idx = 0;
1327                         line_len = strlen(line);
1328                         if (line_len >= MAX_LINELEN)
1329                                 line[MAX_LINELEN-1] = '\0';
1330                         st_parm->history[i++] = line;
1331                 }
1332                 st_parm->cnt_history = i;
1333         }
1334 }
1335
1336 /* state->flags is already checked to be nonzero */
1337 static void save_history(char *str)
1338 {
1339         int fd;
1340         int len, len2;
1341
1342         fd = open(state->hist_file, O_WRONLY | O_CREAT | O_APPEND, 0666);
1343         if (fd < 0)
1344                 return;
1345         xlseek(fd, 0, SEEK_END); /* paranoia */
1346         len = strlen(str);
1347         str[len] = '\n'; /* we (try to) do atomic write */
1348         len2 = full_write(fd, str, len + 1);
1349         str[len] = '\0';
1350         close(fd);
1351         if (len2 != len + 1)
1352                 return; /* "wtf?" */
1353
1354         /* did we write so much that history file needs trimming? */
1355         state->cnt_history_in_file++;
1356         if (state->cnt_history_in_file > MAX_HISTORY * 4) {
1357                 FILE *fp;
1358                 char *new_name;
1359                 line_input_t *st_temp;
1360                 int i;
1361
1362                 /* we may have concurrently written entries from others.
1363                  * load them */
1364                 st_temp = new_line_input_t(state->flags);
1365                 st_temp->hist_file = state->hist_file;
1366                 load_history(st_temp);
1367
1368                 /* write out temp file and replace hist_file atomically */
1369                 new_name = xasprintf("%s.%u.new", state->hist_file, (int) getpid());
1370                 fp = fopen_for_write(new_name);
1371                 if (fp) {
1372                         for (i = 0; i < st_temp->cnt_history; i++)
1373                                 fprintf(fp, "%s\n", st_temp->history[i]);
1374                         fclose(fp);
1375                         if (rename(new_name, state->hist_file) == 0)
1376                                 state->cnt_history_in_file = st_temp->cnt_history;
1377                 }
1378                 free(new_name);
1379                 free_line_input_t(st_temp);
1380         }
1381 }
1382 # else
1383 #  define load_history(a) ((void)0)
1384 #  define save_history(a) ((void)0)
1385 # endif /* FEATURE_COMMAND_SAVEHISTORY */
1386
1387 static void remember_in_history(char *str)
1388 {
1389         int i;
1390
1391         if (!(state->flags & DO_HISTORY))
1392                 return;
1393         if (str[0] == '\0')
1394                 return;
1395         i = state->cnt_history;
1396         /* Don't save dupes */
1397         if (i && strcmp(state->history[i-1], str) == 0)
1398                 return;
1399
1400         free(state->history[MAX_HISTORY]); /* redundant, paranoia */
1401         state->history[MAX_HISTORY] = NULL; /* redundant, paranoia */
1402
1403         /* If history[] is full, remove the oldest command */
1404         /* we need to keep history[MAX_HISTORY] empty, hence >=, not > */
1405         if (i >= MAX_HISTORY) {
1406                 free(state->history[0]);
1407                 for (i = 0; i < MAX_HISTORY-1; i++)
1408                         state->history[i] = state->history[i+1];
1409                 /* i == MAX_HISTORY-1 */
1410         }
1411         /* i <= MAX_HISTORY-1 */
1412         state->history[i++] = xstrdup(str);
1413         /* i <= MAX_HISTORY */
1414         state->cur_history = i;
1415         state->cnt_history = i;
1416 # if MAX_HISTORY > 0 && ENABLE_FEATURE_EDITING_SAVEHISTORY
1417         if ((state->flags & SAVE_HISTORY) && state->hist_file)
1418                 save_history(str);
1419 # endif
1420         IF_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines++;)
1421 }
1422
1423 #else /* MAX_HISTORY == 0 */
1424 # define remember_in_history(a) ((void)0)
1425 #endif /* MAX_HISTORY */
1426
1427
1428 #if ENABLE_FEATURE_EDITING_VI
1429 /*
1430  * vi mode implemented 2005 by Paul Fox <pgf@foxharp.boston.ma.us>
1431  */
1432 static void
1433 vi_Word_motion(int eat)
1434 {
1435         CHAR_T *command = command_ps;
1436
1437         while (cursor < command_len && !BB_isspace(command[cursor]))
1438                 input_forward();
1439         if (eat) while (cursor < command_len && BB_isspace(command[cursor]))
1440                 input_forward();
1441 }
1442
1443 static void
1444 vi_word_motion(int eat)
1445 {
1446         CHAR_T *command = command_ps;
1447
1448         if (BB_isalnum(command[cursor]) || command[cursor] == '_') {
1449                 while (cursor < command_len
1450                  && (BB_isalnum(command[cursor+1]) || command[cursor+1] == '_')
1451                 ) {
1452                         input_forward();
1453                 }
1454         } else if (BB_ispunct(command[cursor])) {
1455                 while (cursor < command_len && BB_ispunct(command[cursor+1]))
1456                         input_forward();
1457         }
1458
1459         if (cursor < command_len)
1460                 input_forward();
1461
1462         if (eat) {
1463                 while (cursor < command_len && BB_isspace(command[cursor]))
1464                         input_forward();
1465         }
1466 }
1467
1468 static void
1469 vi_End_motion(void)
1470 {
1471         CHAR_T *command = command_ps;
1472
1473         input_forward();
1474         while (cursor < command_len && BB_isspace(command[cursor]))
1475                 input_forward();
1476         while (cursor < command_len-1 && !BB_isspace(command[cursor+1]))
1477                 input_forward();
1478 }
1479
1480 static void
1481 vi_end_motion(void)
1482 {
1483         CHAR_T *command = command_ps;
1484
1485         if (cursor >= command_len-1)
1486                 return;
1487         input_forward();
1488         while (cursor < command_len-1 && BB_isspace(command[cursor]))
1489                 input_forward();
1490         if (cursor >= command_len-1)
1491                 return;
1492         if (BB_isalnum(command[cursor]) || command[cursor] == '_') {
1493                 while (cursor < command_len-1
1494                  && (BB_isalnum(command[cursor+1]) || command[cursor+1] == '_')
1495                 ) {
1496                         input_forward();
1497                 }
1498         } else if (BB_ispunct(command[cursor])) {
1499                 while (cursor < command_len-1 && BB_ispunct(command[cursor+1]))
1500                         input_forward();
1501         }
1502 }
1503
1504 static void
1505 vi_Back_motion(void)
1506 {
1507         CHAR_T *command = command_ps;
1508
1509         while (cursor > 0 && BB_isspace(command[cursor-1]))
1510                 input_backward(1);
1511         while (cursor > 0 && !BB_isspace(command[cursor-1]))
1512                 input_backward(1);
1513 }
1514
1515 static void
1516 vi_back_motion(void)
1517 {
1518         CHAR_T *command = command_ps;
1519
1520         if (cursor <= 0)
1521                 return;
1522         input_backward(1);
1523         while (cursor > 0 && BB_isspace(command[cursor]))
1524                 input_backward(1);
1525         if (cursor <= 0)
1526                 return;
1527         if (BB_isalnum(command[cursor]) || command[cursor] == '_') {
1528                 while (cursor > 0
1529                  && (BB_isalnum(command[cursor-1]) || command[cursor-1] == '_')
1530                 ) {
1531                         input_backward(1);
1532                 }
1533         } else if (BB_ispunct(command[cursor])) {
1534                 while (cursor > 0 && BB_ispunct(command[cursor-1]))
1535                         input_backward(1);
1536         }
1537 }
1538 #endif
1539
1540 /* Modelled after bash 4.0 behavior of Ctrl-<arrow> */
1541 static void ctrl_left(void)
1542 {
1543         CHAR_T *command = command_ps;
1544
1545         while (1) {
1546                 CHAR_T c;
1547
1548                 input_backward(1);
1549                 if (cursor == 0)
1550                         break;
1551                 c = command[cursor];
1552                 if (c != ' ' && !BB_ispunct(c)) {
1553                         /* we reached a "word" delimited by spaces/punct.
1554                          * go to its beginning */
1555                         while (1) {
1556                                 c = command[cursor - 1];
1557                                 if (c == ' ' || BB_ispunct(c))
1558                                         break;
1559                                 input_backward(1);
1560                                 if (cursor == 0)
1561                                         break;
1562                         }
1563                         break;
1564                 }
1565         }
1566 }
1567 static void ctrl_right(void)
1568 {
1569         CHAR_T *command = command_ps;
1570
1571         while (1) {
1572                 CHAR_T c;
1573
1574                 c = command[cursor];
1575                 if (c == BB_NUL)
1576                         break;
1577                 if (c != ' ' && !BB_ispunct(c)) {
1578                         /* we reached a "word" delimited by spaces/punct.
1579                          * go to its end + 1 */
1580                         while (1) {
1581                                 input_forward();
1582                                 c = command[cursor];
1583                                 if (c == BB_NUL || c == ' ' || BB_ispunct(c))
1584                                         break;
1585                         }
1586                         break;
1587                 }
1588                 input_forward();
1589         }
1590 }
1591
1592
1593 /*
1594  * read_line_input and its helpers
1595  */
1596
1597 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
1598 static void ask_terminal(void)
1599 {
1600         /* Ask terminal where is the cursor now.
1601          * lineedit_read_key handles response and corrects
1602          * our idea of current cursor position.
1603          * Testcase: run "echo -n long_line_long_line_long_line",
1604          * then type in a long, wrapping command and try to
1605          * delete it using backspace key.
1606          * Note: we print it _after_ prompt, because
1607          * prompt may contain CR. Example: PS1='\[\r\n\]\w '
1608          */
1609         /* Problem: if there is buffered input on stdin,
1610          * the response will be delivered later,
1611          * possibly to an unsuspecting application.
1612          * Testcase: "sleep 1; busybox ash" + press and hold [Enter].
1613          * Result:
1614          * ~/srcdevel/bbox/fix/busybox.t4 #
1615          * ~/srcdevel/bbox/fix/busybox.t4 #
1616          * ^[[59;34~/srcdevel/bbox/fix/busybox.t4 #  <-- garbage
1617          * ~/srcdevel/bbox/fix/busybox.t4 #
1618          *
1619          * Checking for input with poll only makes the race narrower,
1620          * I still can trigger it. Strace:
1621          *
1622          * write(1, "~/srcdevel/bbox/fix/busybox.t4 # ", 33) = 33
1623          * poll([{fd=0, events=POLLIN}], 1, 0) = 0 (Timeout)  <-- no input exists
1624          * write(1, "\33[6n", 4) = 4  <-- send the ESC sequence, quick!
1625          * poll([{fd=0, events=POLLIN}], 1, 4294967295) = 1 ([{fd=0, revents=POLLIN}])
1626          * read(0, "\n", 1)      = 1  <-- oh crap, user's input got in first
1627          */
1628         struct pollfd pfd;
1629
1630         pfd.fd = STDIN_FILENO;
1631         pfd.events = POLLIN;
1632         if (safe_poll(&pfd, 1, 0) == 0) {
1633                 S.sent_ESC_br6n = 1;
1634                 fputs("\033" "[6n", stdout);
1635                 fflush_all(); /* make terminal see it ASAP! */
1636         }
1637 }
1638 #else
1639 #define ask_terminal() ((void)0)
1640 #endif
1641
1642 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1643 static void parse_and_put_prompt(const char *prmt_ptr)
1644 {
1645         cmdedit_prompt = prmt_ptr;
1646         cmdedit_prmt_len = strlen(prmt_ptr);
1647         put_prompt();
1648 }
1649 #else
1650 static void parse_and_put_prompt(const char *prmt_ptr)
1651 {
1652         int prmt_len = 0;
1653         size_t cur_prmt_len = 0;
1654         char flg_not_length = '[';
1655         char *prmt_mem_ptr = xzalloc(1);
1656         char *cwd_buf = xrealloc_getcwd_or_warn(NULL);
1657         char cbuf[2];
1658         char c;
1659         char *pbuf;
1660
1661         cmdedit_prmt_len = 0;
1662
1663         if (!cwd_buf) {
1664                 cwd_buf = (char *)bb_msg_unknown;
1665         }
1666
1667         cbuf[1] = '\0'; /* never changes */
1668
1669         while (*prmt_ptr) {
1670                 char *free_me = NULL;
1671
1672                 pbuf = cbuf;
1673                 c = *prmt_ptr++;
1674                 if (c == '\\') {
1675                         const char *cp = prmt_ptr;
1676                         int l;
1677
1678                         c = bb_process_escape_sequence(&prmt_ptr);
1679                         if (prmt_ptr == cp) {
1680                                 if (*cp == '\0')
1681                                         break;
1682                                 c = *prmt_ptr++;
1683
1684                                 switch (c) {
1685 # if ENABLE_USERNAME_OR_HOMEDIR
1686                                 case 'u':
1687                                         pbuf = user_buf ? user_buf : (char*)"";
1688                                         break;
1689 # endif
1690                                 case 'h':
1691                                         pbuf = free_me = safe_gethostname();
1692                                         *strchrnul(pbuf, '.') = '\0';
1693                                         break;
1694                                 case '$':
1695                                         c = (geteuid() == 0 ? '#' : '$');
1696                                         break;
1697 # if ENABLE_USERNAME_OR_HOMEDIR
1698                                 case 'w':
1699                                         /* /home/user[/something] -> ~[/something] */
1700                                         pbuf = cwd_buf;
1701                                         l = strlen(home_pwd_buf);
1702                                         if (l != 0
1703                                          && strncmp(home_pwd_buf, cwd_buf, l) == 0
1704                                          && (cwd_buf[l]=='/' || cwd_buf[l]=='\0')
1705                                          && strlen(cwd_buf + l) < PATH_MAX
1706                                         ) {
1707                                                 pbuf = free_me = xasprintf("~%s", cwd_buf + l);
1708                                         }
1709                                         break;
1710 # endif
1711                                 case 'W':
1712                                         pbuf = cwd_buf;
1713                                         cp = strrchr(pbuf, '/');
1714                                         if (cp != NULL && cp != pbuf)
1715                                                 pbuf += (cp-pbuf) + 1;
1716                                         break;
1717                                 case '!':
1718                                         pbuf = free_me = xasprintf("%d", num_ok_lines);
1719                                         break;
1720                                 case 'e': case 'E':     /* \e \E = \033 */
1721                                         c = '\033';
1722                                         break;
1723                                 case 'x': case 'X': {
1724                                         char buf2[4];
1725                                         for (l = 0; l < 3;) {
1726                                                 unsigned h;
1727                                                 buf2[l++] = *prmt_ptr;
1728                                                 buf2[l] = '\0';
1729                                                 h = strtoul(buf2, &pbuf, 16);
1730                                                 if (h > UCHAR_MAX || (pbuf - buf2) < l) {
1731                                                         buf2[--l] = '\0';
1732                                                         break;
1733                                                 }
1734                                                 prmt_ptr++;
1735                                         }
1736                                         c = (char)strtoul(buf2, NULL, 16);
1737                                         if (c == 0)
1738                                                 c = '?';
1739                                         pbuf = cbuf;
1740                                         break;
1741                                 }
1742                                 case '[': case ']':
1743                                         if (c == flg_not_length) {
1744                                                 flg_not_length = (flg_not_length == '[' ? ']' : '[');
1745                                                 continue;
1746                                         }
1747                                         break;
1748                                 } /* switch */
1749                         } /* if */
1750                 } /* if */
1751                 cbuf[0] = c;
1752                 cur_prmt_len = strlen(pbuf);
1753                 prmt_len += cur_prmt_len;
1754                 if (flg_not_length != ']')
1755                         cmdedit_prmt_len += cur_prmt_len;
1756                 prmt_mem_ptr = strcat(xrealloc(prmt_mem_ptr, prmt_len+1), pbuf);
1757                 free(free_me);
1758         } /* while */
1759
1760         if (cwd_buf != (char *)bb_msg_unknown)
1761                 free(cwd_buf);
1762         cmdedit_prompt = prmt_mem_ptr;
1763         put_prompt();
1764 }
1765 #endif
1766
1767 static void cmdedit_setwidth(unsigned w, int redraw_flg)
1768 {
1769         cmdedit_termw = w;
1770         if (redraw_flg) {
1771                 /* new y for current cursor */
1772                 int new_y = (cursor + cmdedit_prmt_len) / w;
1773                 /* redraw */
1774                 redraw((new_y >= cmdedit_y ? new_y : cmdedit_y), command_len - cursor);
1775                 fflush_all();
1776         }
1777 }
1778
1779 static void win_changed(int nsig)
1780 {
1781         int sv_errno = errno;
1782         unsigned width;
1783         get_terminal_width_height(0, &width, NULL);
1784         cmdedit_setwidth(width, nsig /* - just a yes/no flag */);
1785         if (nsig == SIGWINCH)
1786                 signal(SIGWINCH, win_changed); /* rearm ourself */
1787         errno = sv_errno;
1788 }
1789
1790 static int lineedit_read_key(char *read_key_buffer)
1791 {
1792         int64_t ic;
1793         int timeout = -1;
1794 #if ENABLE_UNICODE_SUPPORT
1795         char unicode_buf[MB_CUR_MAX + 1];
1796         int unicode_idx = 0;
1797 #endif
1798
1799         while (1) {
1800                 /* Wait for input. TIMEOUT = -1 makes read_key wait even
1801                  * on nonblocking stdin, TIMEOUT = 50 makes sure we won't
1802                  * insist on full MB_CUR_MAX buffer to declare input like
1803                  * "\xff\n",pause,"ls\n" invalid and thus won't lose "ls".
1804                  *
1805                  * Note: read_key sets errno to 0 on success.
1806                  */
1807                 ic = read_key(STDIN_FILENO, read_key_buffer, timeout);
1808                 if (errno) {
1809 #if ENABLE_UNICODE_SUPPORT
1810                         if (errno == EAGAIN && unicode_idx != 0)
1811                                 goto pushback;
1812 #endif
1813                         break;
1814                 }
1815
1816 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
1817                 if ((int32_t)ic == KEYCODE_CURSOR_POS
1818                  && S.sent_ESC_br6n
1819                 ) {
1820                         S.sent_ESC_br6n = 0;
1821                         if (cursor == 0) { /* otherwise it may be bogus */
1822                                 int col = ((ic >> 32) & 0x7fff) - 1;
1823                                 if (col > cmdedit_prmt_len) {
1824                                         cmdedit_x += (col - cmdedit_prmt_len);
1825                                         while (cmdedit_x >= cmdedit_termw) {
1826                                                 cmdedit_x -= cmdedit_termw;
1827                                                 cmdedit_y++;
1828                                         }
1829                                 }
1830                         }
1831                         continue;
1832                 }
1833 #endif
1834
1835 #if ENABLE_UNICODE_SUPPORT
1836                 if (unicode_status == UNICODE_ON) {
1837                         wchar_t wc;
1838
1839                         if ((int32_t)ic < 0) /* KEYCODE_xxx */
1840                                 break;
1841                         // TODO: imagine sequence like: 0xff,<left-arrow>: we are currently losing 0xff...
1842
1843                         unicode_buf[unicode_idx++] = ic;
1844                         unicode_buf[unicode_idx] = '\0';
1845                         if (mbstowcs(&wc, unicode_buf, 1) != 1) {
1846                                 /* Not (yet?) a valid unicode char */
1847                                 if (unicode_idx < MB_CUR_MAX) {
1848                                         timeout = 50;
1849                                         continue;
1850                                 }
1851  pushback:
1852                                 /* Invalid sequence. Save all "bad bytes" except first */
1853                                 read_key_ungets(read_key_buffer, unicode_buf + 1, unicode_idx - 1);
1854 # if !ENABLE_UNICODE_PRESERVE_BROKEN
1855                                 ic = CONFIG_SUBST_WCHAR;
1856 # else
1857                                 ic = unicode_mark_raw_byte(unicode_buf[0]);
1858 # endif
1859                         } else {
1860                                 /* Valid unicode char, return its code */
1861                                 ic = wc;
1862                         }
1863                 }
1864 #endif
1865                 break;
1866         }
1867
1868         return ic;
1869 }
1870
1871 #if ENABLE_UNICODE_BIDI_SUPPORT
1872 static int isrtl_str(void)
1873 {
1874         int idx = cursor;
1875
1876         while (idx < command_len && unicode_bidi_is_neutral_wchar(command_ps[idx]))
1877                 idx++;
1878         return unicode_bidi_isrtl(command_ps[idx]);
1879 }
1880 #else
1881 # define isrtl_str() 0
1882 #endif
1883
1884 /* leave out the "vi-mode"-only case labels if vi editing isn't
1885  * configured. */
1886 #define vi_case(caselabel) IF_FEATURE_EDITING_VI(case caselabel)
1887
1888 /* convert uppercase ascii to equivalent control char, for readability */
1889 #undef CTRL
1890 #define CTRL(a) ((a) & ~0x40)
1891
1892 /* maxsize must be >= 2.
1893  * Returns:
1894  * -1 on read errors or EOF, or on bare Ctrl-D,
1895  * 0  on ctrl-C (the line entered is still returned in 'command'),
1896  * >0 length of input string, including terminating '\n'
1897  */
1898 int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, line_input_t *st)
1899 {
1900         int len;
1901 #if ENABLE_FEATURE_TAB_COMPLETION
1902         smallint lastWasTab = FALSE;
1903 #endif
1904         smallint break_out = 0;
1905 #if ENABLE_FEATURE_EDITING_VI
1906         smallint vi_cmdmode = 0;
1907 #endif
1908         struct termios initial_settings;
1909         struct termios new_settings;
1910         char read_key_buffer[KEYCODE_BUFFER_SIZE];
1911
1912         INIT_S();
1913
1914         if (tcgetattr(STDIN_FILENO, &initial_settings) < 0
1915          || !(initial_settings.c_lflag & ECHO)
1916         ) {
1917                 /* Happens when e.g. stty -echo was run before */
1918                 parse_and_put_prompt(prompt);
1919                 /* fflush_all(); - done by parse_and_put_prompt */
1920                 if (fgets(command, maxsize, stdin) == NULL)
1921                         len = -1; /* EOF or error */
1922                 else
1923                         len = strlen(command);
1924                 DEINIT_S();
1925                 return len;
1926         }
1927
1928         init_unicode();
1929
1930 // FIXME: audit & improve this
1931         if (maxsize > MAX_LINELEN)
1932                 maxsize = MAX_LINELEN;
1933         S.maxsize = maxsize;
1934
1935         /* With null flags, no other fields are ever used */
1936         state = st ? st : (line_input_t*) &const_int_0;
1937 #if MAX_HISTORY > 0
1938 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
1939         if ((state->flags & SAVE_HISTORY) && state->hist_file)
1940                 if (state->cnt_history == 0)
1941                         load_history(state);
1942 # endif
1943         if (state->flags & DO_HISTORY)
1944                 state->cur_history = state->cnt_history;
1945 #endif
1946
1947         /* prepare before init handlers */
1948         cmdedit_y = 0;  /* quasireal y, not true if line > xt*yt */
1949         command_len = 0;
1950 #if ENABLE_UNICODE_SUPPORT
1951         command_ps = xzalloc(maxsize * sizeof(command_ps[0]));
1952 #else
1953         command_ps = command;
1954         command[0] = '\0';
1955 #endif
1956 #define command command_must_not_be_used
1957
1958         new_settings = initial_settings;
1959         new_settings.c_lflag &= ~ICANON;        /* unbuffered input */
1960         /* Turn off echoing and CTRL-C, so we can trap it */
1961         new_settings.c_lflag &= ~(ECHO | ECHONL | ISIG);
1962         /* Hmm, in linux c_cc[] is not parsed if ICANON is off */
1963         new_settings.c_cc[VMIN] = 1;
1964         new_settings.c_cc[VTIME] = 0;
1965         /* Turn off CTRL-C, so we can trap it */
1966 #ifndef _POSIX_VDISABLE
1967 # define _POSIX_VDISABLE '\0'
1968 #endif
1969         new_settings.c_cc[VINTR] = _POSIX_VDISABLE;
1970         tcsetattr_stdin_TCSANOW(&new_settings);
1971
1972         /* Now initialize things */
1973         previous_SIGWINCH_handler = signal(SIGWINCH, win_changed);
1974         win_changed(0); /* do initial resizing */
1975 #if ENABLE_USERNAME_OR_HOMEDIR
1976         {
1977                 struct passwd *entry;
1978
1979                 entry = getpwuid(geteuid());
1980                 if (entry) {
1981                         user_buf = xstrdup(entry->pw_name);
1982                         home_pwd_buf = xstrdup(entry->pw_dir);
1983                 }
1984         }
1985 #endif
1986
1987 #if 0
1988         for (i = 0; i <= MAX_HISTORY; i++)
1989                 bb_error_msg("history[%d]:'%s'", i, state->history[i]);
1990         bb_error_msg("cur_history:%d cnt_history:%d", state->cur_history, state->cnt_history);
1991 #endif
1992
1993         /* Print out the command prompt, optionally ask where cursor is */
1994         parse_and_put_prompt(prompt);
1995         ask_terminal();
1996
1997         read_key_buffer[0] = 0;
1998         while (1) {
1999                 /*
2000                  * The emacs and vi modes share much of the code in the big
2001                  * command loop.  Commands entered when in vi's command mode
2002                  * (aka "escape mode") get an extra bit added to distinguish
2003                  * them - this keeps them from being self-inserted. This
2004                  * clutters the big switch a bit, but keeps all the code
2005                  * in one place.
2006                  */
2007                 enum {
2008                         VI_CMDMODE_BIT = 0x40000000,
2009                         /* 0x80000000 bit flags KEYCODE_xxx */
2010                 };
2011                 int32_t ic, ic_raw;
2012
2013                 fflush_all();
2014                 ic = ic_raw = lineedit_read_key(read_key_buffer);
2015
2016 #if ENABLE_FEATURE_EDITING_VI
2017                 newdelflag = 1;
2018                 if (vi_cmdmode) {
2019                         /* btw, since KEYCODE_xxx are all < 0, this doesn't
2020                          * change ic if it contains one of them: */
2021                         ic |= VI_CMDMODE_BIT;
2022                 }
2023 #endif
2024
2025                 switch (ic) {
2026                 case '\n':
2027                 case '\r':
2028                 vi_case('\n'|VI_CMDMODE_BIT:)
2029                 vi_case('\r'|VI_CMDMODE_BIT:)
2030                         /* Enter */
2031                         goto_new_line();
2032                         break_out = 1;
2033                         break;
2034                 case CTRL('A'):
2035                 vi_case('0'|VI_CMDMODE_BIT:)
2036                         /* Control-a -- Beginning of line */
2037                         input_backward(cursor);
2038                         break;
2039                 case CTRL('B'):
2040                 vi_case('h'|VI_CMDMODE_BIT:)
2041                 vi_case('\b'|VI_CMDMODE_BIT:) /* ^H */
2042                 vi_case('\x7f'|VI_CMDMODE_BIT:) /* DEL */
2043                         input_backward(1); /* Move back one character */
2044                         break;
2045                 case CTRL('E'):
2046                 vi_case('$'|VI_CMDMODE_BIT:)
2047                         /* Control-e -- End of line */
2048                         put_till_end_and_adv_cursor();
2049                         break;
2050                 case CTRL('F'):
2051                 vi_case('l'|VI_CMDMODE_BIT:)
2052                 vi_case(' '|VI_CMDMODE_BIT:)
2053                         input_forward(); /* Move forward one character */
2054                         break;
2055                 case '\b':   /* ^H */
2056                 case '\x7f': /* DEL */
2057                         if (!isrtl_str())
2058                                 input_backspace();
2059                         else
2060                                 input_delete(0);
2061                         break;
2062                 case KEYCODE_DELETE:
2063                         if (!isrtl_str())
2064                                 input_delete(0);
2065                         else
2066                                 input_backspace();
2067                         break;
2068 #if ENABLE_FEATURE_TAB_COMPLETION
2069                 case '\t':
2070                         input_tab(&lastWasTab);
2071                         break;
2072 #endif
2073                 case CTRL('K'):
2074                         /* Control-k -- clear to end of line */
2075                         command_ps[cursor] = BB_NUL;
2076                         command_len = cursor;
2077                         printf(SEQ_CLEAR_TILL_END_OF_SCREEN);
2078                         break;
2079                 case CTRL('L'):
2080                 vi_case(CTRL('L')|VI_CMDMODE_BIT:)
2081                         /* Control-l -- clear screen */
2082                         printf("\033[H"); /* cursor to top,left */
2083                         redraw(0, command_len - cursor);
2084                         break;
2085 #if MAX_HISTORY > 0
2086                 case CTRL('N'):
2087                 vi_case(CTRL('N')|VI_CMDMODE_BIT:)
2088                 vi_case('j'|VI_CMDMODE_BIT:)
2089                         /* Control-n -- Get next command in history */
2090                         if (get_next_history())
2091                                 goto rewrite_line;
2092                         break;
2093                 case CTRL('P'):
2094                 vi_case(CTRL('P')|VI_CMDMODE_BIT:)
2095                 vi_case('k'|VI_CMDMODE_BIT:)
2096                         /* Control-p -- Get previous command from history */
2097                         if (get_previous_history())
2098                                 goto rewrite_line;
2099                         break;
2100 #endif
2101                 case CTRL('U'):
2102                 vi_case(CTRL('U')|VI_CMDMODE_BIT:)
2103                         /* Control-U -- Clear line before cursor */
2104                         if (cursor) {
2105                                 command_len -= cursor;
2106                                 memmove(command_ps, command_ps + cursor,
2107                                         (command_len + 1) * sizeof(command_ps[0]));
2108                                 redraw(cmdedit_y, command_len);
2109                         }
2110                         break;
2111                 case CTRL('W'):
2112                 vi_case(CTRL('W')|VI_CMDMODE_BIT:)
2113                         /* Control-W -- Remove the last word */
2114                         while (cursor > 0 && BB_isspace(command_ps[cursor-1]))
2115                                 input_backspace();
2116                         while (cursor > 0 && !BB_isspace(command_ps[cursor-1]))
2117                                 input_backspace();
2118                         break;
2119
2120 #if ENABLE_FEATURE_EDITING_VI
2121                 case 'i'|VI_CMDMODE_BIT:
2122                         vi_cmdmode = 0;
2123                         break;
2124                 case 'I'|VI_CMDMODE_BIT:
2125                         input_backward(cursor);
2126                         vi_cmdmode = 0;
2127                         break;
2128                 case 'a'|VI_CMDMODE_BIT:
2129                         input_forward();
2130                         vi_cmdmode = 0;
2131                         break;
2132                 case 'A'|VI_CMDMODE_BIT:
2133                         put_till_end_and_adv_cursor();
2134                         vi_cmdmode = 0;
2135                         break;
2136                 case 'x'|VI_CMDMODE_BIT:
2137                         input_delete(1);
2138                         break;
2139                 case 'X'|VI_CMDMODE_BIT:
2140                         if (cursor > 0) {
2141                                 input_backward(1);
2142                                 input_delete(1);
2143                         }
2144                         break;
2145                 case 'W'|VI_CMDMODE_BIT:
2146                         vi_Word_motion(1);
2147                         break;
2148                 case 'w'|VI_CMDMODE_BIT:
2149                         vi_word_motion(1);
2150                         break;
2151                 case 'E'|VI_CMDMODE_BIT:
2152                         vi_End_motion();
2153                         break;
2154                 case 'e'|VI_CMDMODE_BIT:
2155                         vi_end_motion();
2156                         break;
2157                 case 'B'|VI_CMDMODE_BIT:
2158                         vi_Back_motion();
2159                         break;
2160                 case 'b'|VI_CMDMODE_BIT:
2161                         vi_back_motion();
2162                         break;
2163                 case 'C'|VI_CMDMODE_BIT:
2164                         vi_cmdmode = 0;
2165                         /* fall through */
2166                 case 'D'|VI_CMDMODE_BIT:
2167                         goto clear_to_eol;
2168
2169                 case 'c'|VI_CMDMODE_BIT:
2170                         vi_cmdmode = 0;
2171                         /* fall through */
2172                 case 'd'|VI_CMDMODE_BIT: {
2173                         int nc, sc;
2174
2175                         ic = lineedit_read_key(read_key_buffer);
2176                         if (errno) /* error */
2177                                 goto prepare_to_die;
2178                         if (ic == ic_raw) { /* "cc", "dd" */
2179                                 input_backward(cursor);
2180                                 goto clear_to_eol;
2181                                 break;
2182                         }
2183
2184                         sc = cursor;
2185                         switch (ic) {
2186                         case 'w':
2187                         case 'W':
2188                         case 'e':
2189                         case 'E':
2190                                 switch (ic) {
2191                                 case 'w':   /* "dw", "cw" */
2192                                         vi_word_motion(vi_cmdmode);
2193                                         break;
2194                                 case 'W':   /* 'dW', 'cW' */
2195                                         vi_Word_motion(vi_cmdmode);
2196                                         break;
2197                                 case 'e':   /* 'de', 'ce' */
2198                                         vi_end_motion();
2199                                         input_forward();
2200                                         break;
2201                                 case 'E':   /* 'dE', 'cE' */
2202                                         vi_End_motion();
2203                                         input_forward();
2204                                         break;
2205                                 }
2206                                 nc = cursor;
2207                                 input_backward(cursor - sc);
2208                                 while (nc-- > cursor)
2209                                         input_delete(1);
2210                                 break;
2211                         case 'b':  /* "db", "cb" */
2212                         case 'B':  /* implemented as B */
2213                                 if (ic == 'b')
2214                                         vi_back_motion();
2215                                 else
2216                                         vi_Back_motion();
2217                                 while (sc-- > cursor)
2218                                         input_delete(1);
2219                                 break;
2220                         case ' ':  /* "d ", "c " */
2221                                 input_delete(1);
2222                                 break;
2223                         case '$':  /* "d$", "c$" */
2224  clear_to_eol:
2225                                 while (cursor < command_len)
2226                                         input_delete(1);
2227                                 break;
2228                         }
2229                         break;
2230                 }
2231                 case 'p'|VI_CMDMODE_BIT:
2232                         input_forward();
2233                         /* fallthrough */
2234                 case 'P'|VI_CMDMODE_BIT:
2235                         put();
2236                         break;
2237                 case 'r'|VI_CMDMODE_BIT:
2238 //FIXME: unicode case?
2239                         ic = lineedit_read_key(read_key_buffer);
2240                         if (errno) /* error */
2241                                 goto prepare_to_die;
2242                         if (ic < ' ' || ic > 255) {
2243                                 beep();
2244                         } else {
2245                                 command_ps[cursor] = ic;
2246                                 bb_putchar(ic);
2247                                 bb_putchar('\b');
2248                         }
2249                         break;
2250                 case '\x1b': /* ESC */
2251                         if (state->flags & VI_MODE) {
2252                                 /* insert mode --> command mode */
2253                                 vi_cmdmode = 1;
2254                                 input_backward(1);
2255                         }
2256                         break;
2257 #endif /* FEATURE_COMMAND_EDITING_VI */
2258
2259 #if MAX_HISTORY > 0
2260                 case KEYCODE_UP:
2261                         if (get_previous_history())
2262                                 goto rewrite_line;
2263                         beep();
2264                         break;
2265                 case KEYCODE_DOWN:
2266                         if (!get_next_history())
2267                                 break;
2268  rewrite_line:
2269                         /* Rewrite the line with the selected history item */
2270                         /* change command */
2271                         command_len = load_string(state->history[state->cur_history] ?
2272                                         state->history[state->cur_history] : "", maxsize);
2273                         /* redraw and go to eol (bol, in vi) */
2274                         redraw(cmdedit_y, (state->flags & VI_MODE) ? 9999 : 0);
2275                         break;
2276 #endif
2277                 case KEYCODE_RIGHT:
2278                         input_forward();
2279                         break;
2280                 case KEYCODE_LEFT:
2281                         input_backward(1);
2282                         break;
2283                 case KEYCODE_CTRL_LEFT:
2284                         ctrl_left();
2285                         break;
2286                 case KEYCODE_CTRL_RIGHT:
2287                         ctrl_right();
2288                         break;
2289                 case KEYCODE_HOME:
2290                         input_backward(cursor);
2291                         break;
2292                 case KEYCODE_END:
2293                         put_till_end_and_adv_cursor();
2294                         break;
2295
2296                 default:
2297                         if (initial_settings.c_cc[VINTR] != 0
2298                          && ic_raw == initial_settings.c_cc[VINTR]
2299                         ) {
2300                                 /* Ctrl-C (usually) - stop gathering input */
2301                                 goto_new_line();
2302                                 command_len = 0;
2303                                 break_out = -1; /* "do not append '\n'" */
2304                                 break;
2305                         }
2306                         if (initial_settings.c_cc[VEOF] != 0
2307                          && ic_raw == initial_settings.c_cc[VEOF]
2308                         ) {
2309                                 /* Ctrl-D (usually) - delete one character,
2310                                  * or exit if len=0 and no chars to delete */
2311                                 if (command_len == 0) {
2312                                         errno = 0;
2313 #if ENABLE_FEATURE_EDITING_VI
2314  prepare_to_die:
2315 #endif
2316                                         break_out = command_len = -1;
2317                                         break;
2318                                 }
2319                                 input_delete(0);
2320                                 break;
2321                         }
2322 //                      /* Control-V -- force insert of next char */
2323 //                      if (c == CTRL('V')) {
2324 //                              if (safe_read(STDIN_FILENO, &c, 1) < 1)
2325 //                                      goto prepare_to_die;
2326 //                              if (c == 0) {
2327 //                                      beep();
2328 //                                      break;
2329 //                              }
2330 //                      }
2331                         if (ic < ' '
2332                          || (!ENABLE_UNICODE_SUPPORT && ic >= 256)
2333                          || (ENABLE_UNICODE_SUPPORT && ic >= VI_CMDMODE_BIT)
2334                         ) {
2335                                 /* If VI_CMDMODE_BIT is set, ic is >= 256
2336                                  * and vi mode ignores unexpected chars.
2337                                  * Otherwise, we are here if ic is a
2338                                  * control char or an unhandled ESC sequence,
2339                                  * which is also ignored.
2340                                  */
2341                                 break;
2342                         }
2343                         if ((int)command_len >= (maxsize - 2)) {
2344                                 /* Not enough space for the char and EOL */
2345                                 break;
2346                         }
2347
2348                         command_len++;
2349                         if (cursor == (command_len - 1)) {
2350                                 /* We are at the end, append */
2351                                 command_ps[cursor] = ic;
2352                                 command_ps[cursor + 1] = BB_NUL;
2353                                 put_cur_glyph_and_inc_cursor();
2354                                 if (unicode_bidi_isrtl(ic))
2355                                         input_backward(1);
2356                         } else {
2357                                 /* In the middle, insert */
2358                                 int sc = cursor;
2359
2360                                 memmove(command_ps + sc + 1, command_ps + sc,
2361                                         (command_len - sc) * sizeof(command_ps[0]));
2362                                 command_ps[sc] = ic;
2363                                 /* is right-to-left char, or neutral one (e.g. comma) was just added to rtl text? */
2364                                 if (!isrtl_str())
2365                                         sc++; /* no */
2366                                 put_till_end_and_adv_cursor();
2367                                 /* to prev x pos + 1 */
2368                                 input_backward(cursor - sc);
2369                         }
2370                         break;
2371                 } /* switch (ic) */
2372
2373                 if (break_out)
2374                         break;
2375
2376 #if ENABLE_FEATURE_TAB_COMPLETION
2377                 if (ic_raw != '\t')
2378                         lastWasTab = FALSE;
2379 #endif
2380         } /* while (1) */
2381
2382 #if ENABLE_FEATURE_EDITING_ASK_TERMINAL
2383         if (S.sent_ESC_br6n) {
2384                 /* "sleep 1; busybox ash" + hold [Enter] to trigger.
2385                  * We sent "ESC [ 6 n", but got '\n' first, and
2386                  * KEYCODE_CURSOR_POS response is now buffered from terminal.
2387                  * It's bad already and not much can be done with it
2388                  * (it _will_ be visible for the next process to read stdin),
2389                  * but without this delay it even shows up on the screen
2390                  * as garbage because we restore echo settings with tcsetattr
2391                  * before it comes in. UGLY!
2392                  */
2393                 usleep(20*1000);
2394         }
2395 #endif
2396
2397 /* End of bug-catching "command_must_not_be_used" trick */
2398 #undef command
2399
2400 #if ENABLE_UNICODE_SUPPORT
2401         command[0] = '\0';
2402         if (command_len > 0)
2403                 command_len = save_string(command, maxsize - 1);
2404         free(command_ps);
2405 #endif
2406
2407         if (command_len > 0)
2408                 remember_in_history(command);
2409
2410         if (break_out > 0) {
2411                 command[command_len++] = '\n';
2412                 command[command_len] = '\0';
2413         }
2414
2415 #if ENABLE_FEATURE_TAB_COMPLETION
2416         free_tab_completion_data();
2417 #endif
2418
2419         /* restore initial_settings */
2420         tcsetattr_stdin_TCSANOW(&initial_settings);
2421         /* restore SIGWINCH handler */
2422         signal(SIGWINCH, previous_SIGWINCH_handler);
2423         fflush_all();
2424
2425         len = command_len;
2426         DEINIT_S();
2427
2428         return len; /* can't return command_len, DEINIT_S() destroys it */
2429 }
2430
2431 #else  /* !FEATURE_EDITING */
2432
2433 #undef read_line_input
2434 int FAST_FUNC read_line_input(const char* prompt, char* command, int maxsize)
2435 {
2436         fputs(prompt, stdout);
2437         fflush_all();
2438         fgets(command, maxsize, stdin);
2439         return strlen(command);
2440 }
2441
2442 #endif  /* !FEATURE_EDITING */
2443
2444
2445 /*
2446  * Testing
2447  */
2448
2449 #ifdef TEST
2450
2451 #include <locale.h>
2452
2453 const char *applet_name = "debug stuff usage";
2454
2455 int main(int argc, char **argv)
2456 {
2457         char buff[MAX_LINELEN];
2458         char *prompt =
2459 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
2460                 "\\[\\033[32;1m\\]\\u@\\[\\x1b[33;1m\\]\\h:"
2461                 "\\[\\033[34;1m\\]\\w\\[\\033[35;1m\\] "
2462                 "\\!\\[\\e[36;1m\\]\\$ \\[\\E[0m\\]";
2463 #else
2464                 "% ";
2465 #endif
2466
2467         while (1) {
2468                 int l;
2469                 l = read_line_input(prompt, buff);
2470                 if (l <= 0 || buff[l-1] != '\n')
2471                         break;
2472                 buff[l-1] = 0;
2473                 printf("*** read_line_input() returned line =%s=\n", buff);
2474         }
2475         printf("*** read_line_input() detect ^D\n");
2476         return 0;
2477 }
2478
2479 #endif  /* TEST */