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