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 <termio.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 static struct termio old_term, new_term;        /* Current termio and the previous termio before starting ash */
  57
  58 static int cmdedit_termw = 80;  /* actual terminal width */
  59 static int cmdedit_scroll = 27; /* width of EOL scrolling region */
  60 static int history_counter = 0; /* Number of commands in history list */
  61 static int reset_term = 0;              /* Set to true if the terminal needs to be reset upon exit */
  62
  63 struct history {
  64         char *s;
  65         struct history *p;
  66         struct history *n;
  67 };
  68
  69 #define xwrite write
  70
  71 void
  72 cmdedit_setwidth(int w)
  73 {
  74         if (w > 20) {
  75                 cmdedit_termw = w;
  76                 cmdedit_scroll = w / 3;
  77         } else {
  78                 errorMsg("\n*** Error: minimum screen width is 21\n");
  79         }
  80 }
  81
  82
  83 void cmdedit_reset_term(void)
  84 {
  85         if (reset_term)
  86                 ioctl(fileno(stdin), TCSETA, (void *) &old_term);
  87 }
  88
  89 void clean_up_and_die(int sig)
  90 {
  91         cmdedit_reset_term();
  92         fprintf(stdout, "\n");
  93         exit(TRUE);
  94 }
  95
  96 /* Go to HOME position */
  97 void input_home(int outputFd, int *cursor)
  98 {
  99         while (*cursor > 0) {
 100                 xwrite(outputFd, "\b", 1);
 101                 --*cursor;
 102         }
 103 }
 104
 105 /* Go to END position */
 106 void input_end(int outputFd, int *cursor, int len)
 107 {
 108         while (*cursor < len) {
 109                 xwrite(outputFd, "\033[C", 3);
 110                 ++*cursor;
 111         }
 112 }
 113
 114 /* Delete the char in back of the cursor */
 115 void input_backspace(char* command, int outputFd, int *cursor, int *len)
 116 {
 117         int j = 0;
 118
 119         if (*cursor > 0) {
 120                 xwrite(outputFd, "\b \b", 3);
 121                 --*cursor;
 122                 memmove(command + *cursor, command + *cursor + 1,
 123                                 BUFSIZ - *cursor + 1);
 124
 125                 for (j = *cursor; j < (BUFSIZ - 1); j++) {
 126                         if (!*(command + j))
 127                                 break;
 128                         else
 129                                 xwrite(outputFd, (command + j), 1);
 130                 }
 131
 132                 xwrite(outputFd, " \b", 2);
 133
 134                 while (j-- > *cursor)
 135                         xwrite(outputFd, "\b", 1);
 136
 137                 --*len;
 138         }
 139 }
 140
 141 /* Delete the char in front of the cursor */
 142 void input_delete(char* command, int outputFd, int cursor, int *len)
 143 {
 144         int j = 0;
 145
 146         if (cursor == *len)
 147                 return;
 148
 149         memmove(command + cursor, command + cursor + 1,
 150                         BUFSIZ - cursor - 1);
 151         for (j = cursor; j < (BUFSIZ - 1); j++) {
 152                 if (!*(command + j))
 153                         break;
 154                 else
 155                         xwrite(outputFd, (command + j), 1);
 156         }
 157
 158         xwrite(outputFd, " \b", 2);
 159
 160         while (j-- > cursor)
 161                 xwrite(outputFd, "\b", 1);
 162         --*len;
 163 }
 164
 165 /* Move forward one charactor */
 166 void input_forward(int outputFd, int *cursor, int len)
 167 {
 168         if (*cursor < len) {
 169                 xwrite(outputFd, "\033[C", 3);
 170                 ++*cursor;
 171         }
 172 }
 173
 174 /* Move back one charactor */
 175 void input_backward(int outputFd, int *cursor)
 176 {
 177         if (*cursor > 0) {
 178                 xwrite(outputFd, "\033[D", 3);
 179                 --*cursor;
 180         }
 181 }
 182
 183
 184
 185 #ifdef BB_FEATURE_SH_TAB_COMPLETION
 186 char** username_tab_completion(char* command, int *num_matches)
 187 {
 188         char **matches = (char **) NULL;
 189         *num_matches=0;
 190         fprintf(stderr, "\nin username_tab_completion\n");
 191         return (matches);
 192 }
 193
 194 #include <dirent.h>
 195 char** exe_n_cwd_tab_completion(char* command, int *num_matches)
 196 {
 197         char *dirName;
 198         char **matches = (char **) NULL;
 199         DIR *dir;
 200         struct dirent *next;
 201
 202         matches = malloc( sizeof(char*)*50);
 203
 204         /* Stick a wildcard onto the command, for later use */
 205         strcat( command, "*");
 206
 207         /* Now wall the current directory */
 208         dirName = get_current_dir_name();
 209         dir = opendir(dirName);
 210         if (!dir) {
 211                 /* Don't print an error, just shut up and return */
 212                 *num_matches=0;
 213                 return (matches);
 214         }
 215         while ((next = readdir(dir)) != NULL) {
 216
 217                 /* Some quick sanity checks */
 218                 if ((strcmp(next->d_name, "..") == 0)
 219                         || (strcmp(next->d_name, ".") == 0)) {
 220                         continue;
 221                 }
 222                 /* See if this matches */
 223                 if (check_wildcard_match(next->d_name, command) == TRUE) {
 224                         /* Cool, found a match.  Add it to the list */
 225                         matches[*num_matches] = malloc(strlen(next->d_name)+1);
 226                         strcpy( matches[*num_matches], next->d_name);
 227                         ++*num_matches;
 228                         //matches = realloc( matches, sizeof(char*)*(*num_matches));
 229                 }
 230         }
 231
 232         return (matches);
 233 }
 234
 235 void input_tab(char* command, int outputFd, int *cursor, int *len)
 236 {
 237         /* Do TAB completion */
 238         static int num_matches=0;
 239         static char **matches = (char **) NULL;
 240         int pos = cursor;
 241
 242
 243         if (lastWasTab == FALSE) {
 244                 char *tmp, *tmp1, *matchBuf;
 245
 246                 /* For now, we will not bother with trying to distinguish
 247                  * whether the cursor is in/at a command extression -- we
 248                  * will always try all possable matches.  If you don't like
 249                  * that then feel free to fix it.
 250                  */
 251
 252                 /* Make a local copy of the string -- up
 253                  * to the position of the cursor */
 254                 matchBuf = (char *) calloc(BUFSIZ, sizeof(char));
 255                 strncpy(matchBuf, command, cursor);
 256                 tmp=matchBuf;
 257
 258                 /* skip past any command seperator tokens */
 259                 while (*tmp && (tmp1=strpbrk(tmp, ";|&{(`")) != NULL) {
 260                         tmp=++tmp1;
 261                         /* skip any leading white space */
 262                         while (*tmp && isspace(*tmp))
 263                                 ++tmp;
 264                 }
 265
 266                 /* skip any leading white space */
 267                 while (*tmp && isspace(*tmp))
 268                         ++tmp;
 269
 270                 /* Free up any memory already allocated */
 271                 if (matches) {
 272                         free(matches);
 273                         matches = (char **) NULL;
 274                 }
 275
 276                 /* If the word starts with `~' and there is no slash in the word,
 277                  * then try completing this word as a username. */
 278
 279                 /* FIXME -- this check is broken! */
 280                 if (*tmp == '~' && !strchr(tmp, '/'))
 281                         matches = username_tab_completion(tmp, &num_matches);
 282
 283                 /* Try to match any executable in our path and everything
 284                  * in the current working directory that matches.  */
 285                 if (!matches)
 286                         matches = exe_n_cwd_tab_completion(tmp, &num_matches);
 287
 288                 /* Don't leak memory */
 289                 free( matchBuf);
 290
 291                 /* Did we find exactly one match? */
 292                 if (matches && num_matches==1) {
 293                         /* write out the matched command */
 294                         strncpy(command+pos, matches[0]+pos, strlen(matches[0])-pos);
 295                         len=strlen(command);
 296                         cursor=len;
 297                         xwrite(outputFd, matches[0]+pos, strlen(matches[0])-pos);
 298                         break;
 299                 }
 300         } else {
 301                 /* Ok -- the last char was a TAB.  Since they
 302                  * just hit TAB again, print a list of all the
 303                  * available choices... */
 304                 if ( matches && num_matches>0 ) {
 305                         int i, col;
 306
 307                         /* Go to the next line */
 308                         xwrite(outputFd, "\n", 1);
 309                         /* Print the list of matches */
 310                         for (i=0,col=0; i<num_matches; i++) {
 311                                 char foo[17];
 312                                 sprintf(foo, "%-14s  ", matches[i]);
 313                                 col += xwrite(outputFd, foo, strlen(foo));
 314                                 if (col > 60 && matches[i+1] != NULL) {
 315                                         xwrite(outputFd, "\n", 1);
 316                                         col = 0;
 317                                 }
 318                         }
 319                         /* Go to the next line */
 320                         xwrite(outputFd, "\n", 1);
 321                         /* Rewrite the prompt */
 322                         xwrite(outputFd, prompt, strlen(prompt));
 323                         /* Rewrite the command */
 324                         xwrite(outputFd, command, len);
 325                         /* Put the cursor back to where it used to be */
 326                         for (cursor=len; cursor > pos; cursor--)
 327                                 xwrite(outputFd, "\b", 1);
 328                 }
 329         }
 330 }
 331 #endif
 332
 333 void get_previous_history(struct history **hp, char* command)
 334 {
 335         free((*hp)->s);
 336         (*hp)->s = strdup(command);
 337         *hp = (*hp)->p;
 338 }
 339
 340 void get_next_history(struct history **hp, char* command)
 341 {
 342         free((*hp)->s);
 343         (*hp)->s = strdup(command);
 344         *hp = (*hp)->n;
 345 }
 346
 347 /*
 348  * This function is used to grab a character buffer
 349  * from the input file descriptor and allows you to
 350  * a string with full command editing (sortof like
 351  * a mini readline).
 352  *
 353  * The following standard commands are not implemented:
 354  * ESC-b -- Move back one word
 355  * ESC-f -- Move forward one word
 356  * ESC-d -- Delete back one word
 357  * ESC-h -- Delete forward one word
 358  * CTL-t -- Transpose two characters
 359  *
 360  * Furthermore, the "vi" command editing keys are not implemented.
 361  *
 362  * TODO: implement TAB command completion. :)
 363  */
 364 extern void cmdedit_read_input(char* prompt, char command[BUFSIZ])
 365 {
 366
 367         int inputFd=fileno(stdin);
 368         int outputFd=fileno(stdout);
 369         int nr = 0;
 370         int len = 0;
 371         int j = 0;
 372         int cursor = 0;
 373         int break_out = 0;
 374         int ret = 0;
 375         int lastWasTab = FALSE;
 376         char c = 0;
 377         struct history *hp = his_end;
 378
 379         memset(command, 0, sizeof(command));
 380         if (!reset_term) {
 381                 ioctl(inputFd, TCGETA, (void *) &old_term);
 382                 memcpy(&new_term, &old_term, sizeof(struct termio));
 383
 384                 new_term.c_cc[VMIN] = 1;
 385                 new_term.c_cc[VTIME] = 0;
 386                 new_term.c_lflag &= ~ICANON;    /* unbuffered input */
 387                 new_term.c_lflag &= ~ECHO;
 388                 reset_term = 1;
 389                 ioctl(inputFd, TCSETA, (void *) &new_term);
 390         } else {
 391                 ioctl(inputFd, TCSETA, (void *) &new_term);
 392         }
 393
 394         memset(command, 0, BUFSIZ);
 395
 396         while (1) {
 397
 398                 if ((ret = read(inputFd, &c, 1)) < 1)
 399                         return;
 400
 401                 switch (c) {
 402                 case '\n':
 403                 case '\r':
 404                         /* Enter */
 405                         *(command + len++ + 1) = c;
 406                         xwrite(outputFd, &c, 1);
 407                         break_out = 1;
 408                         break;
 409                 case 1:
 410                         /* Control-a -- Beginning of line */
 411                         input_home(outputFd, &cursor);
 412                 case 2:
 413                         /* Control-b -- Move back one character */
 414                         input_backward(outputFd, &cursor);
 415                         break;
 416                 case 4:
 417                         /* Control-d -- Delete one character, or exit
 418                          * if the len=0 and no chars to delete */
 419                         if (len == 0) {
 420                                 xwrite(outputFd, "exit", 4);
 421                                 clean_up_and_die(0);
 422                         } else {
 423                                 input_delete(command, outputFd, cursor, &len);
 424                         }
 425                         break;
 426                 case 5:
 427                         /* Control-e -- End of line */
 428                         input_end(outputFd, &cursor, len);
 429                         break;
 430                 case 6:
 431                         /* Control-f -- Move forward one character */
 432                         input_forward(outputFd, &cursor, len);
 433                         break;
 434                 case '\b':
 435                 case DEL:
 436                         /* control-h and DEL */
 437                         input_backspace(command, outputFd, &cursor, &len);
 438                         break;
 439                 case '\t':
 440 #ifdef BB_FEATURE_SH_TAB_COMPLETION
 441                         input_tab(command, outputFd, &cursor, &len);
 442 #endif
 443                         break;
 444                 case 14:
 445                         /* Control-n -- Get next command in history */
 446                         if (hp && hp->n && hp->n->s) {
 447                                 get_next_history(&hp, command);
 448                                 goto rewrite_line;
 449                         } else {
 450                                 xwrite(outputFd, "\007", 1);
 451                         }
 452                         break;
 453                 case 16:
 454                         /* Control-p -- Get previous command from history */
 455                         if (hp && hp->p) {
 456                                 get_previous_history(&hp, command);
 457                                 goto rewrite_line;
 458                         } else {
 459                                 xwrite(outputFd, "\007", 1);
 460                         }
 461                         break;
 462                 case ESC:{
 463                                 /* escape sequence follows */
 464                                 if ((ret = read(inputFd, &c, 1)) < 1)
 465                                         return;
 466
 467                                 if (c == '[') { /* 91 */
 468                                         if ((ret = read(inputFd, &c, 1)) < 1)
 469                                                 return;
 470
 471                                         switch (c) {
 472                                         case 'A':
 473                                                 /* Up Arrow -- Get previous command from history */
 474                                                 if (hp && hp->p) {
 475                                                         get_previous_history(&hp, command);
 476                                                         goto rewrite_line;
 477                                                 } else {
 478                                                         xwrite(outputFd, "\007", 1);
 479                                                 }
 480                                                 break;
 481                                         case 'B':
 482                                                 /* Down Arrow -- Get next command in history */
 483                                                 if (hp && hp->n && hp->n->s) {
 484                                                         get_next_history(&hp, command);
 485                                                         goto rewrite_line;
 486                                                 } else {
 487                                                         xwrite(outputFd, "\007", 1);
 488                                                 }
 489                                                 break;
 490
 491                                                 /* Rewrite the line with the selected history item */
 492                                           rewrite_line:
 493                                                 /* erase old command from command line */
 494                                                 len = strlen(command)-strlen(hp->s);
 495                                                 while (len>0)
 496                                                         input_backspace(command, outputFd, &cursor, &len);
 497                                                 input_home(outputFd, &cursor);
 498
 499                                                 /* write new command */
 500                                                 strcpy(command, hp->s);
 501                                                 len = strlen(hp->s);
 502                                                 xwrite(outputFd, command, len);
 503                                                 cursor = len;
 504                                                 break;
 505                                         case 'C':
 506                                                 /* Right Arrow -- Move forward one character */
 507                                                 input_forward(outputFd, &cursor, len);
 508                                                 break;
 509                                         case 'D':
 510                                                 /* Left Arrow -- Move back one character */
 511                                                 input_backward(outputFd, &cursor);
 512                                                 break;
 513                                         case '3':
 514                                                 /* Delete */
 515                                                 input_delete(command, outputFd, cursor, &len);
 516                                                 break;
 517                                         case '1':
 518                                                 /* Home (Ctrl-A) */
 519                                                 input_home(outputFd, &cursor);
 520                                                 break;
 521                                         case '4':
 522                                                 /* End (Ctrl-E) */
 523                                                 input_end(outputFd, &cursor, len);
 524                                                 break;
 525                                         default:
 526                                                 xwrite(outputFd, "\007", 1);
 527                                         }
 528                                         if (c == '1' || c == '3' || c == '4')
 529                                                 if ((ret = read(inputFd, &c, 1)) < 1)
 530                                                         return; /* read 126 (~) */
 531                                 }
 532                                 if (c == 'O') {
 533                                         /* 79 */
 534                                         if ((ret = read(inputFd, &c, 1)) < 1)
 535                                                 return;
 536                                         switch (c) {
 537                                         case 'H':
 538                                                 /* Home (xterm) */
 539                                                 input_home(outputFd, &cursor);
 540                                                 break;
 541                                         case 'F':
 542                                                 /* End (xterm) */
 543                                                 input_end(outputFd, &cursor, len);
 544                                                 break;
 545                                         default:
 546                                                 xwrite(outputFd, "\007", 1);
 547                                         }
 548                                 }
 549                                 c = 0;
 550                                 break;
 551                         }
 552
 553                 default:                                /* If it's regular input, do the normal thing */
 554
 555                         if (!isprint(c)) {      /* Skip non-printable characters */
 556                                 break;
 557                         }
 558
 559                         if (len >= (BUFSIZ - 2))        /* Need to leave space for enter */
 560                                 break;
 561
 562                         len++;
 563
 564                         if (cursor == (len - 1)) {      /* Append if at the end of the line */
 565                                 *(command + cursor) = c;
 566                         } else {                        /* Insert otherwise */
 567                                 memmove(command + cursor + 1, command + cursor,
 568                                                 len - cursor - 1);
 569
 570                                 *(command + cursor) = c;
 571
 572                                 for (j = cursor; j < len; j++)
 573                                         xwrite(outputFd, command + j, 1);
 574                                 for (; j > cursor; j--)
 575                                         xwrite(outputFd, "\033[D", 3);
 576                         }
 577
 578                         cursor++;
 579                         xwrite(outputFd, &c, 1);
 580                         break;
 581                 }
 582                 if (c == '\t')
 583                         lastWasTab = TRUE;
 584                 else
 585                         lastWasTab = FALSE;
 586
 587                 if (break_out)                  /* Enter is the command terminator, no more input. */
 588                         break;
 589         }
 590
 591         nr = len + 1;
 592         ioctl(inputFd, TCSETA, (void *) &old_term);
 593         reset_term = 0;
 594
 595
 596         /* Handle command history log */
 597         if (*(command)) {
 598
 599                 struct history *h = his_end;
 600
 601                 if (!h) {
 602                         /* No previous history */
 603                         h = his_front = malloc(sizeof(struct history));
 604                         h->n = malloc(sizeof(struct history));
 605
 606                         h->p = NULL;
 607                         h->s = strdup(command);
 608                         h->n->p = h;
 609                         h->n->n = NULL;
 610                         h->n->s = NULL;
 611                         his_end = h->n;
 612                         history_counter++;
 613                 } else {
 614                         /* Add a new history command */
 615                         h->n = malloc(sizeof(struct history));
 616
 617                         h->n->p = h;
 618                         h->n->n = NULL;
 619                         h->n->s = NULL;
 620                         h->s = strdup(command);
 621                         his_end = h->n;
 622
 623                         /* After max history, remove the oldest command */
 624                         if (history_counter >= MAX_HISTORY) {
 625
 626                                 struct history *p = his_front->n;
 627
 628                                 p->p = NULL;
 629                                 free(his_front->s);
 630                                 free(his_front);
 631                                 his_front = p;
 632                         } else {
 633                                 history_counter++;
 634                         }
 635                 }
 636         }
 637
 638         return;
 639 }
 640
 641 extern void cmdedit_init(void)
 642 {
 643         atexit(cmdedit_reset_term);
 644         signal(SIGINT, clean_up_and_die);
 645         signal(SIGQUIT, clean_up_and_die);
 646         signal(SIGTERM, clean_up_and_die);
 647 }
 648 #endif                                                  /* BB_FEATURE_SH_COMMAND_EDITING */