shell/cmdedit.c

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