shell/cmdedit.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Termios command line History and Editting, originally
   4  * intended for NetBSD sh (ash)
   5  * Copyright (c) 1999
   6  *      Main code:            Adam Rogoyski <rogoyski@cs.utexas.edu>
   7  *      Etc:                  Dave Cinege <dcinege@psychosis.com>
   8  *  Majorly adjusted/re-written for busybox:
   9  *                            Erik Andersen <andersee@debian.org>
  10  *
  11  * You may use this code as you wish, so long as the original author(s)
  12  * are attributed in any redistributions of the source code.
  13  * This code is 'as is' with no warranty.
  14  * This code may safely be consumed by a BSD or GPL license.
  15  *
  16  * v 0.5  19990328      Initial release
  17  *
  18  * Future plans: Simple file and path name completion. (like BASH)
  19  *
  20  */
  21
  22 /*
  23    Usage and Known bugs:
  24    Terminal key codes are not extensive, and more will probably
  25    need to be added. This version was created on Debian GNU/Linux 2.x.
  26    Delete, Backspace, Home, End, and the arrow keys were tested
  27    to work in an Xterm and console. Ctrl-A also works as Home.
  28    Ctrl-E also works as End. The binary size increase is <3K.
  29
  30    Editting will not display correctly for lines greater then the
  31    terminal width. (more then one line.) However, history will.
  32  */
  33
  34 #include "internal.h"
  35 #ifdef BB_FEATURE_SH_COMMAND_EDITING
  36
  37 #include <stdio.h>
  38 #include <errno.h>
  39 #include <unistd.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <sys/ioctl.h>
  43 #include <ctype.h>
  44 #include <signal.h>
  45
  46
  47 #define  MAX_HISTORY   15               /* Maximum length of the linked list for the command line history */
  48
  49 #define ESC     27
  50 #define DEL     127
  51 #define member(c, s) ((c) ? ((char *)strchr ((s), (c)) != (char *)NULL) : 0)
  52 #define whitespace(c) (((c) == ' ') || ((c) == '\t'))
  53
  54 static struct history *his_front = NULL;        /* First element in command line list */
  55 static struct history *his_end = NULL;  /* Last element in command line list */
  56
  57 /* ED: sparc termios is broken: revert back to old termio handling. */
  58 #ifdef BB_FEATURE_USE_TERMIOS
  59
  60 #if #cpu(sparc)
  61 #      include <termio.h>
  62 #      define termios termio
  63 #      define setTermSettings(fd,argp) ioctl(fd,TCSETAF,argp)
  64 #      define getTermSettings(fd,argp) ioctl(fd,TCGETA,argp)
  65 #else
  66 #      include <termios.h>
  67 #      define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
  68 #      define getTermSettings(fd,argp) tcgetattr(fd, argp);
  69 #endif
  70
  71 /* Current termio and the previous termio before starting sh */
  72 struct termios initial_settings, new_settings;
  73
  74
  75 #ifndef _POSIX_VDISABLE
  76 #define _POSIX_VDISABLE '\0'
  77 #endif
  78
  79 #endif
  80
  81
  82
  83 static int cmdedit_termw = 80;  /* actual terminal width */
  84 static int cmdedit_scroll = 27; /* width of EOL scrolling region */
  85 static int history_counter = 0; /* Number of commands in history list */
  86 static int reset_term = 0;              /* Set to true if the terminal needs to be reset upon exit */
  87
  88 struct history {
  89         char *s;
  90         struct history *p;
  91         struct history *n;
  92 };
  93
  94 #define xwrite write
  95
  96 /*
  97  * TODO: Someday we want to implement 'horizontal scrolling' of the
  98  * command-line when the user has typed more than the current width. This
  99  * would allow the user to see a 'window' of what he has typed.
 100  */
 101 void
 102 cmdedit_setwidth(int w)
 103 {
 104         if (w > 20) {
 105                 cmdedit_termw = w;
 106                 cmdedit_scroll = w / 3;
 107         } else {
 108                 errorMsg("\n*** Error: minimum screen width is 21\n");
 109         }
 110 }
 111
 112
 113 void cmdedit_reset_term(void)
 114 {
 115         if (reset_term)
 116                 /* sparc and other have broken termios support: use old termio handling. */
 117                 setTermSettings(fileno(stdin), (void*) &initial_settings);
 118 #ifdef BB_FEATURE_CLEAN_UP
 119         if (his_front) {
 120                 struct history *n;
 121                 //while(his_front!=his_end) {
 122                 while(his_front!=his_end) {
 123                         n = his_front->n;
 124                         free(his_front->s);
 125                         free(his_front);
 126                         his_front=n;
 127                 }
 128         }
 129 #endif
 130 }
 131
 132 void clean_up_and_die(int sig)
 133 {
 134         cmdedit_reset_term();
 135         fprintf(stdout, "\n");
 136         if (sig!=SIGINT)
 137                 exit(TRUE);
 138 }
 139
 140 /* Go to HOME position */
 141 void input_home(int outputFd, int *cursor)
 142 {
 143         while (*cursor > 0) {
 144                 xwrite(outputFd, "\b", 1);
 145                 --*cursor;
 146         }
 147 }
 148
 149 /* Go to END position */
 150 void input_end(int outputFd, int *cursor, int len)
 151 {
 152         while (*cursor < len) {
 153                 xwrite(outputFd, "\033[C", 3);
 154                 ++*cursor;
 155         }
 156 }
 157
 158 /* Delete the char in back of the cursor */
 159 void input_backspace(char* command, int outputFd, int *cursor, int *len)
 160 {
 161         int j = 0;
 162
 163 /* Debug crap */
 164 //fprintf(stderr, "\nerik: len=%d, cursor=%d, strlen(command)='%d'\n", *len, *cursor, strlen(command));
 165 //xwrite(outputFd, command, *len);
 166 //*cursor = *len;
 167
 168
 169         if (*cursor > 0) {
 170                 xwrite(outputFd, "\b \b", 3);
 171                 --*cursor;
 172                 memmove(command + *cursor, command + *cursor + 1,
 173                                 BUFSIZ - *cursor + 1);
 174
 175                 for (j = *cursor; j < (BUFSIZ - 1); j++) {
 176                         if (!*(command + j))
 177                                 break;
 178                         else
 179                                 xwrite(outputFd, (command + j), 1);
 180                 }
 181
 182                 xwrite(outputFd, " \b", 2);
 183
 184                 while (j-- > *cursor)
 185                         xwrite(outputFd, "\b", 1);
 186
 187                 --*len;
 188         }
 189 }
 190
 191 /* Delete the char in front of the cursor */
 192 void input_delete(char* command, int outputFd, int cursor, int *len)
 193 {
 194         int j = 0;
 195
 196         if (cursor == *len)
 197                 return;
 198
 199         memmove(command + cursor, command + cursor + 1,
 200                         BUFSIZ - cursor - 1);
 201         for (j = cursor; j < (BUFSIZ - 1); j++) {
 202                 if (!*(command + j))
 203                         break;
 204                 else
 205                         xwrite(outputFd, (command + j), 1);
 206         }
 207
 208         xwrite(outputFd, " \b", 2);
 209
 210         while (j-- > cursor)
 211                 xwrite(outputFd, "\b", 1);
 212         --*len;
 213 }
 214
 215 /* Move forward one charactor */
 216 void input_forward(int outputFd, int *cursor, int len)
 217 {
 218         if (*cursor < len) {
 219                 xwrite(outputFd, "\033[C", 3);
 220                 ++*cursor;
 221         }
 222 }
 223
 224 /* Move back one charactor */
 225 void input_backward(int outputFd, int *cursor)
 226 {
 227         if (*cursor > 0) {
 228                 xwrite(outputFd, "\033[D", 3);
 229                 --*cursor;
 230         }
 231 }
 232
 233
 234
 235 #ifdef BB_FEATURE_SH_TAB_COMPLETION
 236 char** username_tab_completion(char* command, int *num_matches)
 237 {
 238         char **matches = (char **) NULL;
 239         *num_matches=0;
 240         fprintf(stderr, "\nin username_tab_completion\n");
 241         return (matches);
 242 }
 243
 244 #include <dirent.h>
 245 char** exe_n_cwd_tab_completion(char* command, int *num_matches)
 246 {
 247         char *dirName;
 248         char **matches = (char **) NULL;
 249         DIR *dir;
 250         struct dirent *next;
 251
 252         matches = malloc( sizeof(char*)*50);
 253
 254         /* Stick a wildcard onto the command, for later use */
 255         strcat( command, "*");
 256
 257         /* Now wall the current directory */
 258         dirName = get_current_dir_name();
 259         dir = opendir(dirName);
 260         if (!dir) {
 261                 /* Don't print an error, just shut up and return */
 262                 *num_matches=0;
 263                 return (matches);
 264         }
 265         while ((next = readdir(dir)) != NULL) {
 266
 267                 /* Some quick sanity checks */
 268                 if ((strcmp(next->d_name, "..") == 0)
 269                         || (strcmp(next->d_name, ".") == 0)) {
 270                         continue;
 271                 }
 272                 /* See if this matches */
 273                 if (check_wildcard_match(next->d_name, command) == TRUE) {
 274                         /* Cool, found a match.  Add it to the list */
 275                         matches[*num_matches] = malloc(strlen(next->d_name)+1);
 276                         strcpy( matches[*num_matches], next->d_name);
 277                         ++*num_matches;
 278                         //matches = realloc( matches, sizeof(char*)*(*num_matches));
 279                 }
 280         }
 281
 282         return (matches);
 283 }
 284
 285 void input_tab(char* command, char* prompt, int outputFd, int *cursor, int *len)
 286 {
 287         /* Do TAB completion */
 288         static int num_matches=0;
 289         static char **matches = (char **) NULL;
 290         int pos = cursor;
 291
 292
 293         if (lastWasTab == FALSE) {
 294                 char *tmp, *tmp1, *matchBuf;
 295
 296                 /* For now, we will not bother with trying to distinguish
 297                  * whether the cursor is in/at a command extression -- we
 298                  * will always try all possible matches.  If you don't like
 299                  * that then feel free to fix it.
 300                  */
 301
 302                 /* Make a local copy of the string -- up
 303                  * to the position of the cursor */
 304                 matchBuf = (char *) calloc(BUFSIZ, sizeof(char));
 305                 strncpy(matchBuf, command, cursor);
 306                 tmp=matchBuf;
 307
 308                 /* skip past any command seperator tokens */
 309                 while (*tmp && (tmp1=strpbrk(tmp, ";|&{(`")) != NULL) {
 310                         tmp=++tmp1;
 311                         /* skip any leading white space */
 312                         while (*tmp && isspace(*tmp))
 313                                 ++tmp;
 314                 }
 315
 316                 /* skip any leading white space */
 317                 while (*tmp && isspace(*tmp))
 318                         ++tmp;
 319
 320                 /* Free up any memory already allocated */
 321                 if (matches) {
 322                         free(matches);
 323                         matches = (char **) NULL;
 324                 }
 325
 326                 /* If the word starts with `~' and there is no slash in the word,
 327                  * then try completing this word as a username. */
 328
 329                 /* FIXME -- this check is broken! */
 330                 if (*tmp == '~' && !strchr(tmp, '/'))
 331                         matches = username_tab_completion(tmp, &num_matches);
 332
 333                 /* Try to match any executable in our path and everything
 334                  * in the current working directory that matches.  */
 335                 if (!matches)
 336                         matches = exe_n_cwd_tab_completion(tmp, &num_matches);
 337
 338                 /* Don't leak memory */
 339                 free( matchBuf);
 340
 341                 /* Did we find exactly one match? */
 342                 if (matches && num_matches==1) {
 343                         /* write out the matched command */
 344                         strncpy(command+pos, matches[0]+pos, strlen(matches[0])-pos);
 345                         len=strlen(command);
 346                         cursor=len;
 347                         xwrite(outputFd, matches[0]+pos, strlen(matches[0])-pos);
 348                         break;
 349                 }
 350         } else {
 351                 /* Ok -- the last char was a TAB.  Since they
 352                  * just hit TAB again, print a list of all the
 353                  * available choices... */
 354                 if ( matches && num_matches>0 ) {
 355                         int i, col;
 356
 357                         /* Go to the next line */
 358                         xwrite(outputFd, "\n", 1);
 359                         /* Print the list of matches */
 360                         for (i=0,col=0; i<num_matches; i++) {
 361                                 char foo[17];
 362                                 sprintf(foo, "%-14s  ", matches[i]);
 363                                 col += xwrite(outputFd, foo, strlen(foo));
 364                                 if (col > 60 && matches[i+1] != NULL) {
 365                                         xwrite(outputFd, "\n", 1);
 366                                         col = 0;
 367                                 }
 368                         }
 369                         /* Go to the next line */
 370                         xwrite(outputFd, "\n", 1);
 371                         /* Rewrite the prompt */
 372                         xwrite(outputFd, prompt, strlen(prompt));
 373                         /* Rewrite the command */
 374                         xwrite(outputFd, command, len);
 375                         /* Put the cursor back to where it used to be */
 376                         for (cursor=len; cursor > pos; cursor--)
 377                                 xwrite(outputFd, "\b", 1);
 378                 }
 379         }
 380 }
 381 #endif
 382
 383 void get_previous_history(struct history **hp, char* command)
 384 {
 385         if ((*hp)->s)
 386                 free((*hp)->s);
 387         (*hp)->s = strdup(command);
 388         *hp = (*hp)->p;
 389 }
 390
 391 void get_next_history(struct history **hp, char* command)
 392 {
 393         if ((*hp)->s)
 394                 free((*hp)->s);
 395         (*hp)->s = strdup(command);
 396         *hp = (*hp)->n;
 397 }
 398
 399 /*
 400  * This function is used to grab a character buffer
 401  * from the input file descriptor and allows you to
 402  * a string with full command editing (sortof like
 403  * a mini readline).
 404  *
 405  * The following standard commands are not implemented:
 406  * ESC-b -- Move back one word
 407  * ESC-f -- Move forward one word
 408  * ESC-d -- Delete back one word
 409  * ESC-h -- Delete forward one word
 410  * CTL-t -- Transpose two characters
 411  *
 412  * Furthermore, the "vi" command editing keys are not implemented.
 413  *
 414  * TODO: implement TAB command completion. :)
 415  */
 416 extern void cmdedit_read_input(char* prompt, char command[BUFSIZ])
 417 {
 418
 419         int inputFd=fileno(stdin);
 420         int outputFd=fileno(stdout);
 421         int nr = 0;
 422         int len = 0;
 423         int j = 0;
 424         int cursor = 0;
 425         int break_out = 0;
 426         int ret = 0;
 427         int lastWasTab = FALSE;
 428         char c = 0;
 429         struct history *hp = his_end;
 430
 431         if (!reset_term) {
 432
 433                 getTermSettings(inputFd, (void*) &initial_settings);
 434                 memcpy(&new_settings, &initial_settings, sizeof(struct termios));
 435                 new_settings.c_cc[VMIN] = 1;
 436                 new_settings.c_cc[VTIME] = 0;
 437                 new_settings.c_cc[VINTR] = _POSIX_VDISABLE; /* Turn off CTRL-C, so we can trap it */
 438                 new_settings.c_lflag &= ~ICANON;        /* unbuffered input */
 439                 new_settings.c_lflag &= ~(ECHO|ECHOCTL|ECHONL); /* Turn off echoing */
 440                 reset_term = 1;
 441         }
 442         setTermSettings(inputFd, (void*) &new_settings);
 443
 444         memset(command, 0, BUFSIZ);
 445
 446         while (1) {
 447
 448                 if ((ret = read(inputFd, &c, 1)) < 1)
 449                         return;
 450                 //fprintf(stderr, "got a '%c' (%d)\n", c, c);
 451
 452                 switch (c) {
 453                 case '\n':
 454                 case '\r':
 455                         /* Enter */
 456                         *(command + len++ + 1) = c;
 457                         xwrite(outputFd, &c, 1);
 458                         break_out = 1;
 459                         break;
 460                 case 1:
 461                         /* Control-a -- Beginning of line */
 462                         input_home(outputFd, &cursor);
 463                 case 2:
 464                         /* Control-b -- Move back one character */
 465                         input_backward(outputFd, &cursor);
 466                         break;
 467                 case 3:
 468                         /* Control-c -- leave the current line,
 469                          * and start over on the next line */
 470
 471                         /* Go to the next line */
 472                         xwrite(outputFd, "\n", 1);
 473
 474                         /* Rewrite the prompt */
 475                         xwrite(outputFd, prompt, strlen(prompt));
 476
 477                         /* Reset the command string */
 478                         memset(command, 0, BUFSIZ);
 479                         len = cursor = 0;
 480
 481                         break;
 482                 case 4:
 483                         /* Control-d -- Delete one character, or exit
 484                          * if the len=0 and no chars to delete */
 485                         if (len == 0) {
 486                                 xwrite(outputFd, "exit", 4);
 487                                 clean_up_and_die(0);
 488                         } else {
 489                                 input_delete(command, outputFd, cursor, &len);
 490                         }
 491                         break;
 492                 case 5:
 493                         /* Control-e -- End of line */
 494                         input_end(outputFd, &cursor, len);
 495                         break;
 496                 case 6:
 497                         /* Control-f -- Move forward one character */
 498                         input_forward(outputFd, &cursor, len);
 499                         break;
 500                 case '\b':
 501                 case DEL:
 502                         /* Control-h and DEL */
 503                         input_backspace(command, outputFd, &cursor, &len);
 504                         break;
 505                 case '\t':
 506 #ifdef BB_FEATURE_SH_TAB_COMPLETION
 507                         input_tab(command, prompt, outputFd, &cursor, &len);
 508 #endif
 509                         break;
 510                 case 14:
 511                         /* Control-n -- Get next command in history */
 512                         if (hp && hp->n && hp->n->s) {
 513                                 get_next_history(&hp, command);
 514                                 goto rewrite_line;
 515                         } else {
 516                                 xwrite(outputFd, "\007", 1);
 517                         }
 518                         break;
 519                 case 16:
 520                         /* Control-p -- Get previous command from history */
 521                         if (hp && hp->p) {
 522                                 get_previous_history(&hp, command);
 523                                 goto rewrite_line;
 524                         } else {
 525                                 xwrite(outputFd, "\007", 1);
 526                         }
 527                         break;
 528                 case ESC:{
 529                                 /* escape sequence follows */
 530                                 if ((ret = read(inputFd, &c, 1)) < 1)
 531                                         return;
 532
 533                                 if (c == '[') { /* 91 */
 534                                         if ((ret = read(inputFd, &c, 1)) < 1)
 535                                                 return;
 536
 537                                         switch (c) {
 538                                         case 'A':
 539                                                 /* Up Arrow -- Get previous command from history */
 540                                                 if (hp && hp->p) {
 541                                                         get_previous_history(&hp, command);
 542                                                         goto rewrite_line;
 543                                                 } else {
 544                                                         xwrite(outputFd, "\007", 1);
 545                                                 }
 546                                                 break;
 547                                         case 'B':
 548                                                 /* Down Arrow -- Get next command in history */
 549                                                 if (hp && hp->n && hp->n->s) {
 550                                                         get_next_history(&hp, command);
 551                                                         goto rewrite_line;
 552                                                 } else {
 553                                                         xwrite(outputFd, "\007", 1);
 554                                                 }
 555                                                 break;
 556
 557                                                 /* Rewrite the line with the selected history item */
 558                                           rewrite_line:
 559                                                 /* erase old command from command line */
 560                                                 len = strlen(command)-strlen(hp->s);
 561
 562                                                 while (len>cursor)
 563                                                         input_delete(command, outputFd, cursor, &len);
 564                                                 while (cursor>0)
 565                                                         input_backspace(command, outputFd, &cursor, &len);
 566                                                 input_home(outputFd, &cursor);
 567
 568                                                 /* write new command */
 569                                                 strcpy(command, hp->s);
 570                                                 len = strlen(hp->s);
 571                                                 xwrite(outputFd, command, len);
 572                                                 cursor = len;
 573                                                 break;
 574                                         case 'C':
 575                                                 /* Right Arrow -- Move forward one character */
 576                                                 input_forward(outputFd, &cursor, len);
 577                                                 break;
 578                                         case 'D':
 579                                                 /* Left Arrow -- Move back one character */
 580                                                 input_backward(outputFd, &cursor);
 581                                                 break;
 582                                         case '3':
 583                                                 /* Delete */
 584                                                 input_delete(command, outputFd, cursor, &len);
 585                                                 break;
 586                                         case '1':
 587                                                 /* Home (Ctrl-A) */
 588                                                 input_home(outputFd, &cursor);
 589                                                 break;
 590                                         case '4':
 591                                                 /* End (Ctrl-E) */
 592                                                 input_end(outputFd, &cursor, len);
 593                                                 break;
 594                                         default:
 595                                                 xwrite(outputFd, "\007", 1);
 596                                         }
 597                                         if (c == '1' || c == '3' || c == '4')
 598                                                 if ((ret = read(inputFd, &c, 1)) < 1)
 599                                                         return; /* read 126 (~) */
 600                                 }
 601                                 if (c == 'O') {
 602                                         /* 79 */
 603                                         if ((ret = read(inputFd, &c, 1)) < 1)
 604                                                 return;
 605                                         switch (c) {
 606                                         case 'H':
 607                                                 /* Home (xterm) */
 608                                                 input_home(outputFd, &cursor);
 609                                                 break;
 610                                         case 'F':
 611                                                 /* End (xterm) */
 612                                                 input_end(outputFd, &cursor, len);
 613                                                 break;
 614                                         default:
 615                                                 xwrite(outputFd, "\007", 1);
 616                                         }
 617                                 }
 618                                 c = 0;
 619                                 break;
 620                         }
 621
 622                 default:                                /* If it's regular input, do the normal thing */
 623
 624                         if (!isprint(c)) {      /* Skip non-printable characters */
 625                                 break;
 626                         }
 627
 628                         if (len >= (BUFSIZ - 2))        /* Need to leave space for enter */
 629                                 break;
 630
 631                         len++;
 632
 633                         if (cursor == (len - 1)) {      /* Append if at the end of the line */
 634                                 *(command + cursor) = c;
 635                         } else {                        /* Insert otherwise */
 636                                 memmove(command + cursor + 1, command + cursor,
 637                                                 len - cursor - 1);
 638
 639                                 *(command + cursor) = c;
 640
 641                                 for (j = cursor; j < len; j++)
 642                                         xwrite(outputFd, command + j, 1);
 643                                 for (; j > cursor; j--)
 644                                         xwrite(outputFd, "\033[D", 3);
 645                         }
 646
 647                         cursor++;
 648                         xwrite(outputFd, &c, 1);
 649                         break;
 650                 }
 651                 if (c == '\t')
 652                         lastWasTab = TRUE;
 653                 else
 654                         lastWasTab = FALSE;
 655
 656                 if (break_out)                  /* Enter is the command terminator, no more input. */
 657                         break;
 658         }
 659
 660         nr = len + 1;
 661         setTermSettings(inputFd, (void *) &initial_settings);
 662         reset_term = 0;
 663
 664
 665         /* Handle command history log */
 666         if (*(command)) {
 667
 668                 struct history *h = his_end;
 669
 670                 if (!h) {
 671                         /* No previous history -- this memory is never freed */
 672                         h = his_front = malloc(sizeof(struct history));
 673                         h->n = malloc(sizeof(struct history));
 674
 675                         h->p = NULL;
 676                         h->s = strdup(command);
 677                         h->n->p = h;
 678                         h->n->n = NULL;
 679                         h->n->s = NULL;
 680                         his_end = h->n;
 681                         history_counter++;
 682                 } else {
 683                         /* Add a new history command -- this memory is never freed */
 684                         h->n = malloc(sizeof(struct history));
 685
 686                         h->n->p = h;
 687                         h->n->n = NULL;
 688                         h->n->s = NULL;
 689                         h->s = strdup(command);
 690                         his_end = h->n;
 691
 692                         /* After max history, remove the oldest command */
 693                         if (history_counter >= MAX_HISTORY) {
 694
 695                                 struct history *p = his_front->n;
 696
 697                                 p->p = NULL;
 698                                 free(his_front->s);
 699                                 free(his_front);
 700                                 his_front = p;
 701                         } else {
 702                                 history_counter++;
 703                         }
 704                 }
 705         }
 706
 707         return;
 708 }
 709
 710 extern void cmdedit_init(void)
 711 {
 712         atexit(cmdedit_reset_term);
 713         signal(SIGKILL, clean_up_and_die);
 714         signal(SIGINT, clean_up_and_die);
 715         signal(SIGQUIT, clean_up_and_die);
 716         signal(SIGTERM, clean_up_and_die);
 717 }
 718 #endif                                                  /* BB_FEATURE_SH_COMMAND_EDITING */