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