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 }
 119
 120 void clean_up_and_die(int sig)
 121 {
 122         cmdedit_reset_term();
 123         fprintf(stdout, "\n");
 124         if (sig!=SIGINT)
 125                 exit(TRUE);
 126 }
 127
 128 /* Go to HOME position */
 129 void input_home(int outputFd, int *cursor)
 130 {
 131         while (*cursor > 0) {
 132                 xwrite(outputFd, "\b", 1);
 133                 --*cursor;
 134         }
 135 }
 136
 137 /* Go to END position */
 138 void input_end(int outputFd, int *cursor, int len)
 139 {
 140         while (*cursor < len) {
 141                 xwrite(outputFd, "\033[C", 3);
 142                 ++*cursor;
 143         }
 144 }
 145
 146 /* Delete the char in back of the cursor */
 147 void input_backspace(char* command, int outputFd, int *cursor, int *len)
 148 {
 149         int j = 0;
 150
 151 /* Debug crap */
 152 //fprintf(stderr, "\nerik: len=%d, cursor=%d, strlen(command)='%d'\n", *len, *cursor, strlen(command));
 153 //xwrite(outputFd, command, *len);
 154 //*cursor = *len;
 155
 156
 157         if (*cursor > 0) {
 158                 xwrite(outputFd, "\b \b", 3);
 159                 --*cursor;
 160                 memmove(command + *cursor, command + *cursor + 1,
 161                                 BUFSIZ - *cursor + 1);
 162
 163                 for (j = *cursor; j < (BUFSIZ - 1); j++) {
 164                         if (!*(command + j))
 165                                 break;
 166                         else
 167                                 xwrite(outputFd, (command + j), 1);
 168                 }
 169
 170                 xwrite(outputFd, " \b", 2);
 171
 172                 while (j-- > *cursor)
 173                         xwrite(outputFd, "\b", 1);
 174
 175                 --*len;
 176         }
 177 }
 178
 179 /* Delete the char in front of the cursor */
 180 void input_delete(char* command, int outputFd, int cursor, int *len)
 181 {
 182         int j = 0;
 183
 184         if (cursor == *len)
 185                 return;
 186
 187         memmove(command + cursor, command + cursor + 1,
 188                         BUFSIZ - cursor - 1);
 189         for (j = cursor; j < (BUFSIZ - 1); j++) {
 190                 if (!*(command + j))
 191                         break;
 192                 else
 193                         xwrite(outputFd, (command + j), 1);
 194         }
 195
 196         xwrite(outputFd, " \b", 2);
 197
 198         while (j-- > cursor)
 199                 xwrite(outputFd, "\b", 1);
 200         --*len;
 201 }
 202
 203 /* Move forward one charactor */
 204 void input_forward(int outputFd, int *cursor, int len)
 205 {
 206         if (*cursor < len) {
 207                 xwrite(outputFd, "\033[C", 3);
 208                 ++*cursor;
 209         }
 210 }
 211
 212 /* Move back one charactor */
 213 void input_backward(int outputFd, int *cursor)
 214 {
 215         if (*cursor > 0) {
 216                 xwrite(outputFd, "\033[D", 3);
 217                 --*cursor;
 218         }
 219 }
 220
 221
 222
 223 #ifdef BB_FEATURE_SH_TAB_COMPLETION
 224 char** username_tab_completion(char* command, int *num_matches)
 225 {
 226         char **matches = (char **) NULL;
 227         *num_matches=0;
 228         fprintf(stderr, "\nin username_tab_completion\n");
 229         return (matches);
 230 }
 231
 232 #include <dirent.h>
 233 char** exe_n_cwd_tab_completion(char* command, int *num_matches)
 234 {
 235         char *dirName;
 236         char **matches = (char **) NULL;
 237         DIR *dir;
 238         struct dirent *next;
 239
 240         matches = malloc( sizeof(char*)*50);
 241
 242         /* Stick a wildcard onto the command, for later use */
 243         strcat( command, "*");
 244
 245         /* Now wall the current directory */
 246         dirName = get_current_dir_name();
 247         dir = opendir(dirName);
 248         if (!dir) {
 249                 /* Don't print an error, just shut up and return */
 250                 *num_matches=0;
 251                 return (matches);
 252         }
 253         while ((next = readdir(dir)) != NULL) {
 254
 255                 /* Some quick sanity checks */
 256                 if ((strcmp(next->d_name, "..") == 0)
 257                         || (strcmp(next->d_name, ".") == 0)) {
 258                         continue;
 259                 }
 260                 /* See if this matches */
 261                 if (check_wildcard_match(next->d_name, command) == TRUE) {
 262                         /* Cool, found a match.  Add it to the list */
 263                         matches[*num_matches] = malloc(strlen(next->d_name)+1);
 264                         strcpy( matches[*num_matches], next->d_name);
 265                         ++*num_matches;
 266                         //matches = realloc( matches, sizeof(char*)*(*num_matches));
 267                 }
 268         }
 269
 270         return (matches);
 271 }
 272
 273 void input_tab(char* command, char* prompt, int outputFd, int *cursor, int *len)
 274 {
 275         /* Do TAB completion */
 276         static int num_matches=0;
 277         static char **matches = (char **) NULL;
 278         int pos = cursor;
 279
 280
 281         if (lastWasTab == FALSE) {
 282                 char *tmp, *tmp1, *matchBuf;
 283
 284                 /* For now, we will not bother with trying to distinguish
 285                  * whether the cursor is in/at a command extression -- we
 286                  * will always try all possible matches.  If you don't like
 287                  * that then feel free to fix it.
 288                  */
 289
 290                 /* Make a local copy of the string -- up
 291                  * to the position of the cursor */
 292                 matchBuf = (char *) calloc(BUFSIZ, sizeof(char));
 293                 strncpy(matchBuf, command, cursor);
 294                 tmp=matchBuf;
 295
 296                 /* skip past any command seperator tokens */
 297                 while (*tmp && (tmp1=strpbrk(tmp, ";|&{(`")) != NULL) {
 298                         tmp=++tmp1;
 299                         /* skip any leading white space */
 300                         while (*tmp && isspace(*tmp))
 301                                 ++tmp;
 302                 }
 303
 304                 /* skip any leading white space */
 305                 while (*tmp && isspace(*tmp))
 306                         ++tmp;
 307
 308                 /* Free up any memory already allocated */
 309                 if (matches) {
 310                         free(matches);
 311                         matches = (char **) NULL;
 312                 }
 313
 314                 /* If the word starts with `~' and there is no slash in the word,
 315                  * then try completing this word as a username. */
 316
 317                 /* FIXME -- this check is broken! */
 318                 if (*tmp == '~' && !strchr(tmp, '/'))
 319                         matches = username_tab_completion(tmp, &num_matches);
 320
 321                 /* Try to match any executable in our path and everything
 322                  * in the current working directory that matches.  */
 323                 if (!matches)
 324                         matches = exe_n_cwd_tab_completion(tmp, &num_matches);
 325
 326                 /* Don't leak memory */
 327                 free( matchBuf);
 328
 329                 /* Did we find exactly one match? */
 330                 if (matches && num_matches==1) {
 331                         /* write out the matched command */
 332                         strncpy(command+pos, matches[0]+pos, strlen(matches[0])-pos);
 333                         len=strlen(command);
 334                         cursor=len;
 335                         xwrite(outputFd, matches[0]+pos, strlen(matches[0])-pos);
 336                         break;
 337                 }
 338         } else {
 339                 /* Ok -- the last char was a TAB.  Since they
 340                  * just hit TAB again, print a list of all the
 341                  * available choices... */
 342                 if ( matches && num_matches>0 ) {
 343                         int i, col;
 344
 345                         /* Go to the next line */
 346                         xwrite(outputFd, "\n", 1);
 347                         /* Print the list of matches */
 348                         for (i=0,col=0; i<num_matches; i++) {
 349                                 char foo[17];
 350                                 sprintf(foo, "%-14s  ", matches[i]);
 351                                 col += xwrite(outputFd, foo, strlen(foo));
 352                                 if (col > 60 && matches[i+1] != NULL) {
 353                                         xwrite(outputFd, "\n", 1);
 354                                         col = 0;
 355                                 }
 356                         }
 357                         /* Go to the next line */
 358                         xwrite(outputFd, "\n", 1);
 359                         /* Rewrite the prompt */
 360                         xwrite(outputFd, prompt, strlen(prompt));
 361                         /* Rewrite the command */
 362                         xwrite(outputFd, command, len);
 363                         /* Put the cursor back to where it used to be */
 364                         for (cursor=len; cursor > pos; cursor--)
 365                                 xwrite(outputFd, "\b", 1);
 366                 }
 367         }
 368 }
 369 #endif
 370
 371 void get_previous_history(struct history **hp, char* command)
 372 {
 373         free((*hp)->s);
 374         (*hp)->s = strdup(command);
 375         *hp = (*hp)->p;
 376 }
 377
 378 void get_next_history(struct history **hp, char* command)
 379 {
 380         free((*hp)->s);
 381         (*hp)->s = strdup(command);
 382         *hp = (*hp)->n;
 383 }
 384
 385 /*
 386  * This function is used to grab a character buffer
 387  * from the input file descriptor and allows you to
 388  * a string with full command editing (sortof like
 389  * a mini readline).
 390  *
 391  * The following standard commands are not implemented:
 392  * ESC-b -- Move back one word
 393  * ESC-f -- Move forward one word
 394  * ESC-d -- Delete back one word
 395  * ESC-h -- Delete forward one word
 396  * CTL-t -- Transpose two characters
 397  *
 398  * Furthermore, the "vi" command editing keys are not implemented.
 399  *
 400  * TODO: implement TAB command completion. :)
 401  */
 402 extern void cmdedit_read_input(char* prompt, char command[BUFSIZ])
 403 {
 404
 405         int inputFd=fileno(stdin);
 406         int outputFd=fileno(stdout);
 407         int nr = 0;
 408         int len = 0;
 409         int j = 0;
 410         int cursor = 0;
 411         int break_out = 0;
 412         int ret = 0;
 413         int lastWasTab = FALSE;
 414         char c = 0;
 415         struct history *hp = his_end;
 416
 417         memset(command, 0, sizeof(command));
 418         if (!reset_term) {
 419
 420                 getTermSettings(inputFd, (void*) &initial_settings);
 421                 memcpy(&new_settings, &initial_settings, sizeof(struct termios));
 422                 new_settings.c_cc[VMIN] = 1;
 423                 new_settings.c_cc[VTIME] = 0;
 424                 new_settings.c_cc[VINTR] = _POSIX_VDISABLE; /* Turn off CTRL-C, so we can trap it */
 425                 new_settings.c_lflag &= ~ICANON;        /* unbuffered input */
 426                 new_settings.c_lflag &= ~(ECHO|ECHOCTL|ECHONL); /* Turn off echoing */
 427                 reset_term = 1;
 428         }
 429         setTermSettings(inputFd, (void*) &new_settings);
 430
 431         memset(command, 0, BUFSIZ);
 432
 433         while (1) {
 434
 435                 if ((ret = read(inputFd, &c, 1)) < 1)
 436                         return;
 437                 //fprintf(stderr, "got a '%c' (%d)\n", c, c);
 438
 439                 switch (c) {
 440                 case '\n':
 441                 case '\r':
 442                         /* Enter */
 443                         *(command + len++ + 1) = c;
 444                         xwrite(outputFd, &c, 1);
 445                         break_out = 1;
 446                         break;
 447                 case 1:
 448                         /* Control-a -- Beginning of line */
 449                         input_home(outputFd, &cursor);
 450                 case 2:
 451                         /* Control-b -- Move back one character */
 452                         input_backward(outputFd, &cursor);
 453                         break;
 454                 case 3:
 455                         /* Control-c -- leave the current line,
 456                          * and start over on the next line */
 457
 458                         /* Go to the next line */
 459                         xwrite(outputFd, "\n", 1);
 460
 461                         /* Rewrite the prompt */
 462                         xwrite(outputFd, prompt, strlen(prompt));
 463
 464                         /* Reset the command string */
 465                         memset(command, 0, sizeof(command));
 466                         len = cursor = 0;
 467
 468                         break;
 469                 case 4:
 470                         /* Control-d -- Delete one character, or exit
 471                          * if the len=0 and no chars to delete */
 472                         if (len == 0) {
 473                                 xwrite(outputFd, "exit", 4);
 474                                 clean_up_and_die(0);
 475                         } else {
 476                                 input_delete(command, outputFd, cursor, &len);
 477                         }
 478                         break;
 479                 case 5:
 480                         /* Control-e -- End of line */
 481                         input_end(outputFd, &cursor, len);
 482                         break;
 483                 case 6:
 484                         /* Control-f -- Move forward one character */
 485                         input_forward(outputFd, &cursor, len);
 486                         break;
 487                 case '\b':
 488                 case DEL:
 489                         /* Control-h and DEL */
 490                         input_backspace(command, outputFd, &cursor, &len);
 491                         break;
 492                 case '\t':
 493 #ifdef BB_FEATURE_SH_TAB_COMPLETION
 494                         input_tab(command, prompt, outputFd, &cursor, &len);
 495 #endif
 496                         break;
 497                 case 14:
 498                         /* Control-n -- Get next command in history */
 499                         if (hp && hp->n && hp->n->s) {
 500                                 get_next_history(&hp, command);
 501                                 goto rewrite_line;
 502                         } else {
 503                                 xwrite(outputFd, "\007", 1);
 504                         }
 505                         break;
 506                 case 16:
 507                         /* Control-p -- Get previous command from history */
 508                         if (hp && hp->p) {
 509                                 get_previous_history(&hp, command);
 510                                 goto rewrite_line;
 511                         } else {
 512                                 xwrite(outputFd, "\007", 1);
 513                         }
 514                         break;
 515                 case ESC:{
 516                                 /* escape sequence follows */
 517                                 if ((ret = read(inputFd, &c, 1)) < 1)
 518                                         return;
 519
 520                                 if (c == '[') { /* 91 */
 521                                         if ((ret = read(inputFd, &c, 1)) < 1)
 522                                                 return;
 523
 524                                         switch (c) {
 525                                         case 'A':
 526                                                 /* Up Arrow -- Get previous command from history */
 527                                                 if (hp && hp->p) {
 528                                                         get_previous_history(&hp, command);
 529                                                         goto rewrite_line;
 530                                                 } else {
 531                                                         xwrite(outputFd, "\007", 1);
 532                                                 }
 533                                                 break;
 534                                         case 'B':
 535                                                 /* Down Arrow -- Get next command in history */
 536                                                 if (hp && hp->n && hp->n->s) {
 537                                                         get_next_history(&hp, command);
 538                                                         goto rewrite_line;
 539                                                 } else {
 540                                                         xwrite(outputFd, "\007", 1);
 541                                                 }
 542                                                 break;
 543
 544                                                 /* Rewrite the line with the selected history item */
 545                                           rewrite_line:
 546                                                 /* erase old command from command line */
 547                                                 len = strlen(command)-strlen(hp->s);
 548
 549                                                 while (len>cursor)
 550                                                         input_delete(command, outputFd, cursor, &len);
 551                                                 while (cursor>0)
 552                                                         input_backspace(command, outputFd, &cursor, &len);
 553                                                 input_home(outputFd, &cursor);
 554
 555                                                 /* write new command */
 556                                                 strcpy(command, hp->s);
 557                                                 len = strlen(hp->s);
 558                                                 xwrite(outputFd, command, len);
 559                                                 cursor = len;
 560                                                 break;
 561                                         case 'C':
 562                                                 /* Right Arrow -- Move forward one character */
 563                                                 input_forward(outputFd, &cursor, len);
 564                                                 break;
 565                                         case 'D':
 566                                                 /* Left Arrow -- Move back one character */
 567                                                 input_backward(outputFd, &cursor);
 568                                                 break;
 569                                         case '3':
 570                                                 /* Delete */
 571                                                 input_delete(command, outputFd, cursor, &len);
 572                                                 break;
 573                                         case '1':
 574                                                 /* Home (Ctrl-A) */
 575                                                 input_home(outputFd, &cursor);
 576                                                 break;
 577                                         case '4':
 578                                                 /* End (Ctrl-E) */
 579                                                 input_end(outputFd, &cursor, len);
 580                                                 break;
 581                                         default:
 582                                                 xwrite(outputFd, "\007", 1);
 583                                         }
 584                                         if (c == '1' || c == '3' || c == '4')
 585                                                 if ((ret = read(inputFd, &c, 1)) < 1)
 586                                                         return; /* read 126 (~) */
 587                                 }
 588                                 if (c == 'O') {
 589                                         /* 79 */
 590                                         if ((ret = read(inputFd, &c, 1)) < 1)
 591                                                 return;
 592                                         switch (c) {
 593                                         case 'H':
 594                                                 /* Home (xterm) */
 595                                                 input_home(outputFd, &cursor);
 596                                                 break;
 597                                         case 'F':
 598                                                 /* End (xterm) */
 599                                                 input_end(outputFd, &cursor, len);
 600                                                 break;
 601                                         default:
 602                                                 xwrite(outputFd, "\007", 1);
 603                                         }
 604                                 }
 605                                 c = 0;
 606                                 break;
 607                         }
 608
 609                 default:                                /* If it's regular input, do the normal thing */
 610
 611                         if (!isprint(c)) {      /* Skip non-printable characters */
 612                                 break;
 613                         }
 614
 615                         if (len >= (BUFSIZ - 2))        /* Need to leave space for enter */
 616                                 break;
 617
 618                         len++;
 619
 620                         if (cursor == (len - 1)) {      /* Append if at the end of the line */
 621                                 *(command + cursor) = c;
 622                         } else {                        /* Insert otherwise */
 623                                 memmove(command + cursor + 1, command + cursor,
 624                                                 len - cursor - 1);
 625
 626                                 *(command + cursor) = c;
 627
 628                                 for (j = cursor; j < len; j++)
 629                                         xwrite(outputFd, command + j, 1);
 630                                 for (; j > cursor; j--)
 631                                         xwrite(outputFd, "\033[D", 3);
 632                         }
 633
 634                         cursor++;
 635                         xwrite(outputFd, &c, 1);
 636                         break;
 637                 }
 638                 if (c == '\t')
 639                         lastWasTab = TRUE;
 640                 else
 641                         lastWasTab = FALSE;
 642
 643                 if (break_out)                  /* Enter is the command terminator, no more input. */
 644                         break;
 645         }
 646
 647         nr = len + 1;
 648         setTermSettings(inputFd, (void *) &initial_settings);
 649         reset_term = 0;
 650
 651
 652         /* Handle command history log */
 653         if (*(command)) {
 654
 655                 struct history *h = his_end;
 656
 657                 if (!h) {
 658                         /* No previous history */
 659                         h = his_front = malloc(sizeof(struct history));
 660                         h->n = malloc(sizeof(struct history));
 661
 662                         h->p = NULL;
 663                         h->s = strdup(command);
 664                         h->n->p = h;
 665                         h->n->n = NULL;
 666                         h->n->s = NULL;
 667                         his_end = h->n;
 668                         history_counter++;
 669                 } else {
 670                         /* Add a new history command */
 671                         h->n = malloc(sizeof(struct history));
 672
 673                         h->n->p = h;
 674                         h->n->n = NULL;
 675                         h->n->s = NULL;
 676                         h->s = strdup(command);
 677                         his_end = h->n;
 678
 679                         /* After max history, remove the oldest command */
 680                         if (history_counter >= MAX_HISTORY) {
 681
 682                                 struct history *p = his_front->n;
 683
 684                                 p->p = NULL;
 685                                 free(his_front->s);
 686                                 free(his_front);
 687                                 his_front = p;
 688                         } else {
 689                                 history_counter++;
 690                         }
 691                 }
 692         }
 693
 694         return;
 695 }
 696
 697 extern void cmdedit_init(void)
 698 {
 699         atexit(cmdedit_reset_term);
 700         signal(SIGKILL, clean_up_and_die);
 701         signal(SIGINT, clean_up_and_die);
 702         signal(SIGQUIT, clean_up_and_die);
 703         signal(SIGTERM, clean_up_and_die);
 704 }
 705 #endif                                                  /* BB_FEATURE_SH_COMMAND_EDITING */