contrib/less/command.c

   1 /* $FreeBSD$ */
   2 /*
   3  * Copyright (C) 1984-2011  Mark Nudelman
   4  *
   5  * You may distribute under the terms of either the GNU General Public
   6  * License or the Less License, as specified in the README file.
   7  *
   8  * For more information about less, or for information on how to
   9  * contact the author, see the README file.
  10  */
  11
  12
  13 /*
  14  * User-level command processor.
  15  */
  16
  17 #include "less.h"
  18 #if MSDOS_COMPILER==WIN32C
  19 #include <windows.h>
  20 #endif
  21 #include "position.h"
  22 #include "option.h"
  23 #include "cmd.h"
  24
  25 extern int erase_char, erase2_char, kill_char;
  26 extern int sigs;
  27 extern int quit_if_one_screen;
  28 extern int squished;
  29 extern int sc_width;
  30 extern int sc_height;
  31 extern int swindow;
  32 extern int jump_sline;
  33 extern int quitting;
  34 extern int wscroll;
  35 extern int top_scroll;
  36 extern int ignore_eoi;
  37 extern int secure;
  38 extern int hshift;
  39 extern int show_attn;
  40 extern int less_is_more;
  41 extern char *every_first_cmd;
  42 extern char *curr_altfilename;
  43 extern char version[];
  44 extern struct scrpos initial_scrpos;
  45 extern IFILE curr_ifile;
  46 extern void constant *ml_search;
  47 extern void constant *ml_examine;
  48 #if SHELL_ESCAPE || PIPEC
  49 extern void constant *ml_shell;
  50 #endif
  51 #if EDITOR
  52 extern char *editor;
  53 extern char *editproto;
  54 #endif
  55 extern int screen_trashed;      /* The screen has been overwritten */
  56 extern int shift_count;
  57 extern int oldbot;
  58 extern int forw_prompt;
  59
  60 #if SHELL_ESCAPE
  61 static char *shellcmd = NULL;   /* For holding last shell command for "!!" */
  62 #endif
  63 static int mca;                 /* The multicharacter command (action) */
  64 static int search_type;         /* The previous type of search */
  65 static LINENUM number;          /* The number typed by the user */
  66 static long fraction;           /* The fractional part of the number */
  67 static struct loption *curropt;
  68 static int opt_lower;
  69 static int optflag;
  70 static int optgetname;
  71 static POSITION bottompos;
  72 static int save_hshift;
  73 #if PIPEC
  74 static char pipec;
  75 #endif
  76
  77 struct ungot {
  78         struct ungot *ug_next;
  79         char ug_char;
  80 };
  81 static struct ungot* ungot = NULL;
  82 static int unget_end = 0;
  83
  84 static void multi_search();
  85
  86 /*
  87  * Move the cursor to start of prompt line before executing a command.
  88  * This looks nicer if the command takes a long time before
  89  * updating the screen.
  90  */
  91         static void
  92 cmd_exec()
  93 {
  94 #if HILITE_SEARCH
  95         clear_attn();
  96 #endif
  97         clear_bot();
  98         flush();
  99 }
 100
 101 /*
 102  * Set up the display to start a new multi-character command.
 103  */
 104         static void
 105 start_mca(action, prompt, mlist, cmdflags)
 106         int action;
 107         char *prompt;
 108         void *mlist;
 109         int cmdflags;
 110 {
 111         mca = action;
 112         clear_bot();
 113         clear_cmd();
 114         cmd_putstr(prompt);
 115         set_mlist(mlist, cmdflags);
 116 }
 117
 118         public int
 119 in_mca()
 120 {
 121         return (mca != 0 && mca != A_PREFIX);
 122 }
 123
 124 /*
 125  * Set up the display to start a new search command.
 126  */
 127         static void
 128 mca_search()
 129 {
 130 #if HILITE_SEARCH
 131         if (search_type & SRCH_FILTER)
 132                 mca = A_FILTER;
 133         else
 134 #endif
 135         if (search_type & SRCH_FORW)
 136                 mca = A_F_SEARCH;
 137         else
 138                 mca = A_B_SEARCH;
 139
 140         clear_bot();
 141         clear_cmd();
 142
 143         if (search_type & SRCH_NO_MATCH)
 144                 cmd_putstr("Non-match ");
 145         if (search_type & SRCH_FIRST_FILE)
 146                 cmd_putstr("First-file ");
 147         if (search_type & SRCH_PAST_EOF)
 148                 cmd_putstr("EOF-ignore ");
 149         if (search_type & SRCH_NO_MOVE)
 150                 cmd_putstr("Keep-pos ");
 151         if (search_type & SRCH_NO_REGEX)
 152                 cmd_putstr("Regex-off ");
 153
 154 #if HILITE_SEARCH
 155         if (search_type & SRCH_FILTER)
 156                 cmd_putstr("&/");
 157         else
 158 #endif
 159         if (search_type & SRCH_FORW)
 160                 cmd_putstr("/");
 161         else
 162                 cmd_putstr("?");
 163         set_mlist(ml_search, 0);
 164 }
 165
 166 /*
 167  * Set up the display to start a new toggle-option command.
 168  */
 169         static void
 170 mca_opt_toggle()
 171 {
 172         int no_prompt;
 173         int flag;
 174         char *dash;
 175
 176         no_prompt = (optflag & OPT_NO_PROMPT);
 177         flag = (optflag & ~OPT_NO_PROMPT);
 178         dash = (flag == OPT_NO_TOGGLE) ? "_" : "-";
 179
 180         mca = A_OPT_TOGGLE;
 181         clear_bot();
 182         clear_cmd();
 183         cmd_putstr(dash);
 184         if (optgetname)
 185                 cmd_putstr(dash);
 186         if (no_prompt)
 187                 cmd_putstr("(P)");
 188         switch (flag)
 189         {
 190         case OPT_UNSET:
 191                 cmd_putstr("+");
 192                 break;
 193         case OPT_SET:
 194                 cmd_putstr("!");
 195                 break;
 196         }
 197         set_mlist(NULL, 0);
 198 }
 199
 200 /*
 201  * Execute a multicharacter command.
 202  */
 203         static void
 204 exec_mca()
 205 {
 206         register char *cbuf;
 207
 208         cmd_exec();
 209         cbuf = get_cmdbuf();
 210
 211         switch (mca)
 212         {
 213         case A_F_SEARCH:
 214         case A_B_SEARCH:
 215                 multi_search(cbuf, (int) number);
 216                 break;
 217 #if HILITE_SEARCH
 218         case A_FILTER:
 219                 search_type ^= SRCH_NO_MATCH;
 220                 set_filter_pattern(cbuf, search_type);
 221                 break;
 222 #endif
 223         case A_FIRSTCMD:
 224                 /*
 225                  * Skip leading spaces or + signs in the string.
 226                  */
 227                 while (*cbuf == '+' || *cbuf == ' ')
 228                         cbuf++;
 229                 if (every_first_cmd != NULL)
 230                         free(every_first_cmd);
 231                 if (*cbuf == '\0')
 232                         every_first_cmd = NULL;
 233                 else
 234                         every_first_cmd = save(cbuf);
 235                 break;
 236         case A_OPT_TOGGLE:
 237                 toggle_option(curropt, opt_lower, cbuf, optflag);
 238                 curropt = NULL;
 239                 break;
 240         case A_F_BRACKET:
 241                 match_brac(cbuf[0], cbuf[1], 1, (int) number);
 242                 break;
 243         case A_B_BRACKET:
 244                 match_brac(cbuf[1], cbuf[0], 0, (int) number);
 245                 break;
 246 #if EXAMINE
 247         case A_EXAMINE:
 248                 if (secure)
 249                         break;
 250                 edit_list(cbuf);
 251 #if TAGS
 252                 /* If tag structure is loaded then clean it up. */
 253                 cleantags();
 254 #endif
 255                 break;
 256 #endif
 257 #if SHELL_ESCAPE
 258         case A_SHELL:
 259                 /*
 260                  * !! just uses whatever is in shellcmd.
 261                  * Otherwise, copy cmdbuf to shellcmd,
 262                  * expanding any special characters ("%" or "#").
 263                  */
 264                 if (*cbuf != '!')
 265                 {
 266                         if (shellcmd != NULL)
 267                                 free(shellcmd);
 268                         shellcmd = fexpand(cbuf);
 269                 }
 270
 271                 if (secure)
 272                         break;
 273                 if (shellcmd == NULL)
 274                         lsystem("", "!done");
 275                 else
 276                         lsystem(shellcmd, "!done");
 277                 break;
 278 #endif
 279 #if PIPEC
 280         case A_PIPE:
 281                 if (secure)
 282                         break;
 283                 (void) pipe_mark(pipec, cbuf);
 284                 error("|done", NULL_PARG);
 285                 break;
 286 #endif
 287         }
 288 }
 289
 290 /*
 291  * Is a character an erase or kill char?
 292  */
 293         static int
 294 is_erase_char(c)
 295         int c;
 296 {
 297         return (c == erase_char || c == erase2_char || c == kill_char);
 298 }
 299
 300 /*
 301  * Handle the first char of an option (after the initial dash).
 302  */
 303         static int
 304 mca_opt_first_char(c)
 305     int c;
 306 {
 307         int flag = (optflag & ~OPT_NO_PROMPT);
 308         if (flag == OPT_NO_TOGGLE)
 309         {
 310                 switch (c)
 311                 {
 312                 case '_':
 313                         /* "__" = long option name. */
 314                         optgetname = TRUE;
 315                         mca_opt_toggle();
 316                         return (MCA_MORE);
 317                 }
 318         } else
 319         {
 320                 switch (c)
 321                 {
 322                 case '+':
 323                         /* "-+" = UNSET. */
 324                         optflag = (flag == OPT_UNSET) ?
 325                                 OPT_TOGGLE : OPT_UNSET;
 326                         mca_opt_toggle();
 327                         return (MCA_MORE);
 328                 case '!':
 329                         /* "-!" = SET */
 330                         optflag = (flag == OPT_SET) ?
 331                                 OPT_TOGGLE : OPT_SET;
 332                         mca_opt_toggle();
 333                         return (MCA_MORE);
 334                 case CONTROL('P'):
 335                         optflag ^= OPT_NO_PROMPT;
 336                         mca_opt_toggle();
 337                         return (MCA_MORE);
 338                 case '-':
 339                         /* "--" = long option name. */
 340                         optgetname = TRUE;
 341                         mca_opt_toggle();
 342                         return (MCA_MORE);
 343                 }
 344         }
 345         /* Char was not handled here. */
 346         return (NO_MCA);
 347 }
 348
 349 /*
 350  * Add a char to a long option name.
 351  * See if we've got a match for an option name yet.
 352  * If so, display the complete name and stop
 353  * accepting chars until user hits RETURN.
 354  */
 355         static int
 356 mca_opt_nonfirst_char(c)
 357         int c;
 358 {
 359         char *p;
 360         char *oname;
 361
 362         if (curropt != NULL)
 363         {
 364                 /*
 365                  * Already have a match for the name.
 366                  * Don't accept anything but erase/kill.
 367                  */
 368                 if (is_erase_char(c))
 369                         return (MCA_DONE);
 370                 return (MCA_MORE);
 371         }
 372         /*
 373          * Add char to cmd buffer and try to match
 374          * the option name.
 375          */
 376         if (cmd_char(c) == CC_QUIT)
 377                 return (MCA_DONE);
 378         p = get_cmdbuf();
 379         opt_lower = ASCII_IS_LOWER(p[0]);
 380         curropt = findopt_name(&p, &oname, NULL);
 381         if (curropt != NULL)
 382         {
 383                 /*
 384                  * Got a match.
 385                  * Remember the option and
 386                  * display the full option name.
 387                  */
 388                 cmd_reset();
 389                 mca_opt_toggle();
 390                 for (p = oname;  *p != '\0';  p++)
 391                 {
 392                         c = *p;
 393                         if (!opt_lower && ASCII_IS_LOWER(c))
 394                                 c = ASCII_TO_UPPER(c);
 395                         if (cmd_char(c) != CC_OK)
 396                                 return (MCA_DONE);
 397                 }
 398         }
 399         return (MCA_MORE);
 400 }
 401
 402 /*
 403  * Handle a char of an option toggle command.
 404  */
 405         static int
 406 mca_opt_char(c)
 407         int c;
 408 {
 409         PARG parg;
 410
 411         /*
 412          * This may be a short option (single char),
 413          * or one char of a long option name,
 414          * or one char of the option parameter.
 415          */
 416         if (curropt == NULL && len_cmdbuf() == 0)
 417         {
 418                 int ret = mca_opt_first_char(c);
 419                 if (ret != NO_MCA)
 420                         return (ret);
 421         }
 422         if (optgetname)
 423         {
 424                 /* We're getting a long option name.  */
 425                 if (c != '\n' && c != '\r')
 426                         return (mca_opt_nonfirst_char(c));
 427                 if (curropt == NULL)
 428                 {
 429                         parg.p_string = get_cmdbuf();
 430                         error("There is no --%s option", &parg);
 431                         return (MCA_DONE);
 432                 }
 433                 optgetname = FALSE;
 434                 cmd_reset();
 435         } else
 436         {
 437                 if (is_erase_char(c))
 438                         return (NO_MCA);
 439                 if (curropt != NULL)
 440                         /* We're getting the option parameter. */
 441                         return (NO_MCA);
 442                 curropt = findopt(c);
 443                 if (curropt == NULL)
 444                 {
 445                         parg.p_string = propt(c);
 446                         error("There is no %s option", &parg);
 447                         return (MCA_DONE);
 448                 }
 449         }
 450         /*
 451          * If the option which was entered does not take a
 452          * parameter, toggle the option immediately,
 453          * so user doesn't have to hit RETURN.
 454          */
 455         if ((optflag & ~OPT_NO_PROMPT) != OPT_TOGGLE ||
 456             !opt_has_param(curropt))
 457         {
 458                 toggle_option(curropt, ASCII_IS_LOWER(c), "", optflag);
 459                 return (MCA_DONE);
 460         }
 461         /*
 462          * Display a prompt appropriate for the option parameter.
 463          */
 464         start_mca(A_OPT_TOGGLE, opt_prompt(curropt), (void*)NULL, 0);
 465         return (MCA_MORE);
 466 }
 467
 468 /*
 469  * Handle a char of a search command.
 470  */
 471         static int
 472 mca_search_char(c)
 473         int c;
 474 {
 475         int flag = 0;
 476
 477         /*
 478          * Certain characters as the first char of
 479          * the pattern have special meaning:
 480          *      !  Toggle the NO_MATCH flag
 481          *      *  Toggle the PAST_EOF flag
 482          *      @  Toggle the FIRST_FILE flag
 483          */
 484         if (len_cmdbuf() > 0)
 485                 return (NO_MCA);
 486
 487         switch (c)
 488         {
 489         case '*':
 490                 if (less_is_more)
 491                         break;
 492         case CONTROL('E'): /* ignore END of file */
 493                 if (mca != A_FILTER)
 494                         flag = SRCH_PAST_EOF;
 495                 break;
 496         case '@':
 497                 if (less_is_more)
 498                         break;
 499         case CONTROL('F'): /* FIRST file */
 500                 if (mca != A_FILTER)
 501                         flag = SRCH_FIRST_FILE;
 502                 break;
 503         case CONTROL('K'): /* KEEP position */
 504                 if (mca != A_FILTER)
 505                         flag = SRCH_NO_MOVE;
 506                 break;
 507         case CONTROL('R'): /* Don't use REGULAR EXPRESSIONS */
 508                 flag = SRCH_NO_REGEX;
 509                 break;
 510         case CONTROL('N'): /* NOT match */
 511         case '!':
 512                 flag = SRCH_NO_MATCH;
 513                 break;
 514         }
 515
 516         if (flag != 0)
 517         {
 518                 search_type ^= flag;
 519                 mca_search();
 520                 return (MCA_MORE);
 521         }
 522         return (NO_MCA);
 523 }
 524
 525 /*
 526  * Handle a character of a multi-character command.
 527  */
 528         static int
 529 mca_char(c)
 530         int c;
 531 {
 532         int ret;
 533
 534         switch (mca)
 535         {
 536         case 0:
 537                 /*
 538                  * We're not in a multicharacter command.
 539                  */
 540                 return (NO_MCA);
 541
 542         case A_PREFIX:
 543                 /*
 544                  * In the prefix of a command.
 545                  * This not considered a multichar command
 546                  * (even tho it uses cmdbuf, etc.).
 547                  * It is handled in the commands() switch.
 548                  */
 549                 return (NO_MCA);
 550
 551         case A_DIGIT:
 552                 /*
 553                  * Entering digits of a number.
 554                  * Terminated by a non-digit.
 555                  */
 556                 if (!((c >= '0' && c <= '9') || c == '.') &&
 557                   editchar(c, EC_PEEK|EC_NOHISTORY|EC_NOCOMPLETE|EC_NORIGHTLEFT) == A_INVALID)
 558                 {
 559                         /*
 560                          * Not part of the number.
 561                          * End the number and treat this char
 562                          * as a normal command character.
 563                          */
 564                         number = cmd_int(&fraction);
 565                         mca = 0;
 566                         cmd_accept();
 567                         return (NO_MCA);
 568                 }
 569                 break;
 570
 571         case A_OPT_TOGGLE:
 572                 ret = mca_opt_char(c);
 573                 if (ret != NO_MCA)
 574                         return (ret);
 575                 break;
 576
 577         case A_F_SEARCH:
 578         case A_B_SEARCH:
 579         case A_FILTER:
 580                 ret = mca_search_char(c);
 581                 if (ret != NO_MCA)
 582                         return (ret);
 583                 break;
 584
 585         default:
 586                 /* Other multicharacter command. */
 587                 break;
 588         }
 589
 590         /*
 591          * The multichar command is terminated by a newline.
 592          */
 593         if (c == '\n' || c == '\r')
 594         {
 595                 /*
 596                  * Execute the command.
 597                  */
 598                 exec_mca();
 599                 return (MCA_DONE);
 600         }
 601
 602         /*
 603          * Append the char to the command buffer.
 604          */
 605         if (cmd_char(c) == CC_QUIT)
 606                 /*
 607                  * Abort the multi-char command.
 608                  */
 609                 return (MCA_DONE);
 610
 611         if ((mca == A_F_BRACKET || mca == A_B_BRACKET) && len_cmdbuf() >= 2)
 612         {
 613                 /*
 614                  * Special case for the bracket-matching commands.
 615                  * Execute the command after getting exactly two
 616                  * characters from the user.
 617                  */
 618                 exec_mca();
 619                 return (MCA_DONE);
 620         }
 621
 622         /*
 623          * Need another character.
 624          */
 625         return (MCA_MORE);
 626 }
 627
 628 /*
 629  * Discard any buffered file data.
 630  */
 631         static void
 632 clear_buffers()
 633 {
 634         if (!(ch_getflags() & CH_CANSEEK))
 635                 return;
 636         ch_flush();
 637         clr_linenum();
 638 #if HILITE_SEARCH
 639         clr_hilite();
 640 #endif
 641 }
 642
 643 /*
 644  * Make sure the screen is displayed.
 645  */
 646         static void
 647 make_display()
 648 {
 649         /*
 650          * If nothing is displayed yet, display starting from initial_scrpos.
 651          */
 652         if (empty_screen())
 653         {
 654                 if (initial_scrpos.pos == NULL_POSITION)
 655                         /*
 656                          * {{ Maybe this should be:
 657                          *    jump_loc(ch_zero(), jump_sline);
 658                          *    but this behavior seems rather unexpected
 659                          *    on the first screen. }}
 660                          */
 661                         jump_loc(ch_zero(), 1);
 662                 else
 663                         jump_loc(initial_scrpos.pos, initial_scrpos.ln);
 664         } else if (screen_trashed)
 665         {
 666                 int save_top_scroll = top_scroll;
 667                 int save_ignore_eoi = ignore_eoi;
 668                 top_scroll = 1;
 669                 ignore_eoi = 0;
 670                 if (screen_trashed == 2)
 671                 {
 672                         /* Special case used by ignore_eoi: re-open the input file
 673                          * and jump to the end of the file. */
 674                         reopen_curr_ifile();
 675                         jump_forw();
 676                 }
 677                 repaint();
 678                 top_scroll = save_top_scroll;
 679                 ignore_eoi = save_ignore_eoi;
 680         }
 681 }
 682
 683 /*
 684  * Display the appropriate prompt.
 685  */
 686         static void
 687 prompt()
 688 {
 689         register char *p;
 690
 691         if (ungot != NULL)
 692         {
 693                 /*
 694                  * No prompt necessary if commands are from
 695                  * ungotten chars rather than from the user.
 696                  */
 697                 return;
 698         }
 699
 700         /*
 701          * Make sure the screen is displayed.
 702          */
 703         make_display();
 704         bottompos = position(BOTTOM_PLUS_ONE);
 705
 706         /*
 707          * If we've hit EOF on the last file and the -E flag is set, quit.
 708          */
 709         if (get_quit_at_eof() == OPT_ONPLUS &&
 710             eof_displayed() && !(ch_getflags() & CH_HELPFILE) &&
 711             next_ifile(curr_ifile) == NULL_IFILE)
 712                 quit(QUIT_OK);
 713
 714         /*
 715          * If the entire file is displayed and the -F flag is set, quit.
 716          */
 717         if (quit_if_one_screen &&
 718             entire_file_displayed() && !(ch_getflags() & CH_HELPFILE) &&
 719             next_ifile(curr_ifile) == NULL_IFILE)
 720                 quit(QUIT_OK);
 721
 722 #if MSDOS_COMPILER==WIN32C
 723         /*
 724          * In Win32, display the file name in the window title.
 725          */
 726         if (!(ch_getflags() & CH_HELPFILE))
 727                 SetConsoleTitle(pr_expand("Less?f - %f.", 0));
 728 #endif
 729         /*
 730          * Select the proper prompt and display it.
 731          */
 732         /*
 733          * If the previous action was a forward movement,
 734          * don't clear the bottom line of the display;
 735          * just print the prompt since the forward movement guarantees
 736          * that we're in the right position to display the prompt.
 737          * Clearing the line could cause a problem: for example, if the last
 738          * line displayed ended at the right screen edge without a newline,
 739          * then clearing would clear the last displayed line rather than
 740          * the prompt line.
 741          */
 742         if (!forw_prompt)
 743                 clear_bot();
 744         clear_cmd();
 745         forw_prompt = 0;
 746         p = pr_string();
 747         if (is_filtering())
 748                 putstr("& ");
 749         if (p == NULL || *p == '\0')
 750                 putchr(':');
 751         else
 752         {
 753                 at_enter(AT_STANDOUT);
 754                 putstr(p);
 755                 at_exit();
 756         }
 757         clear_eol();
 758 }
 759
 760 /*
 761  * Display the less version message.
 762  */
 763         public void
 764 dispversion()
 765 {
 766         PARG parg;
 767
 768         parg.p_string = version;
 769         error("less %s", &parg);
 770 }
 771
 772 /*
 773  * Get command character.
 774  * The character normally comes from the keyboard,
 775  * but may come from ungotten characters
 776  * (characters previously given to ungetcc or ungetsc).
 777  */
 778         public int
 779 getcc()
 780 {
 781         if (unget_end)
 782         {
 783                 /*
 784                  * We have just run out of ungotten chars.
 785                  */
 786                 unget_end = 0;
 787                 if (len_cmdbuf() == 0 || !empty_screen())
 788                         return (getchr());
 789                 /*
 790                  * Command is incomplete, so try to complete it.
 791                  */
 792                 switch (mca)
 793                 {
 794                 case A_DIGIT:
 795                         /*
 796                          * We have a number but no command.  Treat as #g.
 797                          */
 798                         return ('g');
 799
 800                 case A_F_SEARCH:
 801                 case A_B_SEARCH:
 802                         /*
 803                          * We have "/string" but no newline.  Add the \n.
 804                          */
 805                         return ('\n');
 806
 807                 default:
 808                         /*
 809                          * Some other incomplete command.  Let user complete it.
 810                          */
 811                         return (getchr());
 812                 }
 813         }
 814
 815         if (ungot == NULL)
 816         {
 817                 /*
 818                  * Normal case: no ungotten chars, so get one from the user.
 819                  */
 820                 return (getchr());
 821         }
 822
 823         /*
 824          * Return the next ungotten char.
 825          */
 826         {
 827                 struct ungot *ug = ungot;
 828                 char c = ug->ug_char;
 829                 ungot = ug->ug_next;
 830                 free(ug);
 831                 unget_end = (ungot == NULL);
 832                 return (c);
 833         }
 834 }
 835
 836 /*
 837  * "Unget" a command character.
 838  * The next getcc() will return this character.
 839  */
 840         public void
 841 ungetcc(c)
 842         int c;
 843 {
 844         struct ungot *ug = (struct ungot *) ecalloc(1, sizeof(struct ungot));
 845
 846         ug->ug_char = c;
 847         ug->ug_next = ungot;
 848         ungot = ug;
 849         unget_end = 0;
 850 }
 851
 852 /*
 853  * Unget a whole string of command characters.
 854  * The next sequence of getcc()'s will return this string.
 855  */
 856         public void
 857 ungetsc(s)
 858         char *s;
 859 {
 860         register char *p;
 861
 862         for (p = s + strlen(s) - 1;  p >= s;  p--)
 863                 ungetcc(*p);
 864 }
 865
 866 /*
 867  * Search for a pattern, possibly in multiple files.
 868  * If SRCH_FIRST_FILE is set, begin searching at the first file.
 869  * If SRCH_PAST_EOF is set, continue the search thru multiple files.
 870  */
 871         static void
 872 multi_search(pattern, n)
 873         char *pattern;
 874         int n;
 875 {
 876         register int nomore;
 877         IFILE save_ifile;
 878         int changed_file;
 879
 880         changed_file = 0;
 881         save_ifile = save_curr_ifile();
 882
 883         if (search_type & SRCH_FIRST_FILE)
 884         {
 885                 /*
 886                  * Start at the first (or last) file
 887                  * in the command line list.
 888                  */
 889                 if (search_type & SRCH_FORW)
 890                         nomore = edit_first();
 891                 else
 892                         nomore = edit_last();
 893                 if (nomore)
 894                 {
 895                         unsave_ifile(save_ifile);
 896                         return;
 897                 }
 898                 changed_file = 1;
 899                 search_type &= ~SRCH_FIRST_FILE;
 900         }
 901
 902         for (;;)
 903         {
 904                 n = search(search_type, pattern, n);
 905                 /*
 906                  * The SRCH_NO_MOVE flag doesn't "stick": it gets cleared
 907                  * after being used once.  This allows "n" to work after
 908                  * using a /@@ search.
 909                  */
 910                 search_type &= ~SRCH_NO_MOVE;
 911                 if (n == 0)
 912                 {
 913                         /*
 914                          * Found it.
 915                          */
 916                         unsave_ifile(save_ifile);
 917                         return;
 918                 }
 919
 920                 if (n < 0)
 921                         /*
 922                          * Some kind of error in the search.
 923                          * Error message has been printed by search().
 924                          */
 925                         break;
 926
 927                 if ((search_type & SRCH_PAST_EOF) == 0)
 928                         /*
 929                          * We didn't find a match, but we're
 930                          * supposed to search only one file.
 931                          */
 932                         break;
 933                 /*
 934                  * Move on to the next file.
 935                  */
 936                 if (search_type & SRCH_FORW)
 937                         nomore = edit_next(1);
 938                 else
 939                         nomore = edit_prev(1);
 940                 if (nomore)
 941                         break;
 942                 changed_file = 1;
 943         }
 944
 945         /*
 946          * Didn't find it.
 947          * Print an error message if we haven't already.
 948          */
 949         if (n > 0)
 950                 error("Pattern not found", NULL_PARG);
 951
 952         if (changed_file)
 953         {
 954                 /*
 955                  * Restore the file we were originally viewing.
 956                  */
 957                 reedit_ifile(save_ifile);
 958         } else
 959         {
 960                 unsave_ifile(save_ifile);
 961         }
 962 }
 963
 964 /*
 965  * Main command processor.
 966  * Accept and execute commands until a quit command.
 967  */
 968         public void
 969 commands()
 970 {
 971         register int c;
 972         register int action;
 973         register char *cbuf;
 974         int newaction;
 975         int save_search_type;
 976         char *extra;
 977         char tbuf[2];
 978         PARG parg;
 979         IFILE old_ifile;
 980         IFILE new_ifile;
 981         char *tagfile;
 982
 983         search_type = SRCH_FORW;
 984         wscroll = (sc_height + 1) / 2;
 985         newaction = A_NOACTION;
 986
 987         for (;;)
 988         {
 989                 mca = 0;
 990                 cmd_accept();
 991                 number = 0;
 992                 curropt = NULL;
 993
 994                 /*
 995                  * See if any signals need processing.
 996                  */
 997                 if (sigs)
 998                 {
 999                         psignals();
1000                         if (quitting)
1001                                 quit(QUIT_SAVED_STATUS);
1002                 }
1003
1004                 /*
1005                  * See if window size changed, for systems that don't
1006                  * generate SIGWINCH.
1007                  */
1008                 check_winch();
1009
1010                 /*
1011                  * Display prompt and accept a character.
1012                  */
1013                 cmd_reset();
1014                 prompt();
1015                 if (sigs)
1016                         continue;
1017                 if (newaction == A_NOACTION)
1018                         c = getcc();
1019
1020         again:
1021                 if (sigs)
1022                         continue;
1023
1024                 if (newaction != A_NOACTION)
1025                 {
1026                         action = newaction;
1027                         newaction = A_NOACTION;
1028                 } else
1029                 {
1030                         /*
1031                          * If we are in a multicharacter command, call mca_char.
1032                          * Otherwise we call fcmd_decode to determine the
1033                          * action to be performed.
1034                          */
1035                         if (mca)
1036                                 switch (mca_char(c))
1037                                 {
1038                                 case MCA_MORE:
1039                                         /*
1040                                          * Need another character.
1041                                          */
1042                                         c = getcc();
1043                                         goto again;
1044                                 case MCA_DONE:
1045                                         /*
1046                                          * Command has been handled by mca_char.
1047                                          * Start clean with a prompt.
1048                                          */
1049                                         continue;
1050                                 case NO_MCA:
1051                                         /*
1052                                          * Not a multi-char command
1053                                          * (at least, not anymore).
1054                                          */
1055                                         break;
1056                                 }
1057
1058                         /*
1059                          * Decode the command character and decide what to do.
1060                          */
1061                         if (mca)
1062                         {
1063                                 /*
1064                                  * We're in a multichar command.
1065                                  * Add the character to the command buffer
1066                                  * and display it on the screen.
1067                                  * If the user backspaces past the start
1068                                  * of the line, abort the command.
1069                                  */
1070                                 if (cmd_char(c) == CC_QUIT || len_cmdbuf() == 0)
1071                                         continue;
1072                                 cbuf = get_cmdbuf();
1073                         } else
1074                         {
1075                                 /*
1076                                  * Don't use cmd_char if we're starting fresh
1077                                  * at the beginning of a command, because we
1078                                  * don't want to echo the command until we know
1079                                  * it is a multichar command.  We also don't
1080                                  * want erase_char/kill_char to be treated
1081                                  * as line editing characters.
1082                                  */
1083                                 tbuf[0] = c;
1084                                 tbuf[1] = '\0';
1085                                 cbuf = tbuf;
1086                         }
1087                         extra = NULL;
1088                         action = fcmd_decode(cbuf, &extra);
1089                         /*
1090                          * If an "extra" string was returned,
1091                          * process it as a string of command characters.
1092                          */
1093                         if (extra != NULL)
1094                                 ungetsc(extra);
1095                 }
1096                 /*
1097                  * Clear the cmdbuf string.
1098                  * (But not if we're in the prefix of a command,
1099                  * because the partial command string is kept there.)
1100                  */
1101                 if (action != A_PREFIX)
1102                         cmd_reset();
1103
1104                 switch (action)
1105                 {
1106                 case A_DIGIT:
1107                         /*
1108                          * First digit of a number.
1109                          */
1110                         start_mca(A_DIGIT, ":", (void*)NULL, CF_QUIT_ON_ERASE);
1111                         goto again;
1112
1113                 case A_F_WINDOW:
1114                         /*
1115                          * Forward one window (and set the window size).
1116                          */
1117                         if (number > 0)
1118                                 swindow = (int) number;
1119                         /* FALLTHRU */
1120                 case A_F_SCREEN:
1121                         /*
1122                          * Forward one screen.
1123                          */
1124                         if (number <= 0)
1125                                 number = get_swindow();
1126                         cmd_exec();
1127                         if (show_attn)
1128                                 set_attnpos(bottompos);
1129                         forward((int) number, 0, 1);
1130                         break;
1131
1132                 case A_B_WINDOW:
1133                         /*
1134                          * Backward one window (and set the window size).
1135                          */
1136                         if (number > 0)
1137                                 swindow = (int) number;
1138                         /* FALLTHRU */
1139                 case A_B_SCREEN:
1140                         /*
1141                          * Backward one screen.
1142                          */
1143                         if (number <= 0)
1144                                 number = get_swindow();
1145                         cmd_exec();
1146                         backward((int) number, 0, 1);
1147                         break;
1148
1149                 case A_F_LINE:
1150                         /*
1151                          * Forward N (default 1) line.
1152                          */
1153                         if (number <= 0)
1154                                 number = 1;
1155                         cmd_exec();
1156                         if (show_attn == OPT_ONPLUS && number > 1)
1157                                 set_attnpos(bottompos);
1158                         forward((int) number, 0, 0);
1159                         break;
1160
1161                 case A_B_LINE:
1162                         /*
1163                          * Backward N (default 1) line.
1164                          */
1165                         if (number <= 0)
1166                                 number = 1;
1167                         cmd_exec();
1168                         backward((int) number, 0, 0);
1169                         break;
1170
1171                 case A_FF_LINE:
1172                         /*
1173                          * Force forward N (default 1) line.
1174                          */
1175                         if (number <= 0)
1176                                 number = 1;
1177                         cmd_exec();
1178                         if (show_attn == OPT_ONPLUS && number > 1)
1179                                 set_attnpos(bottompos);
1180                         forward((int) number, 1, 0);
1181                         break;
1182
1183                 case A_BF_LINE:
1184                         /*
1185                          * Force backward N (default 1) line.
1186                          */
1187                         if (number <= 0)
1188                                 number = 1;
1189                         cmd_exec();
1190                         backward((int) number, 1, 0);
1191                         break;
1192
1193                 case A_FF_SCREEN:
1194                         /*
1195                          * Force forward one screen.
1196                          */
1197                         if (number <= 0)
1198                                 number = get_swindow();
1199                         cmd_exec();
1200                         if (show_attn == OPT_ONPLUS)
1201                                 set_attnpos(bottompos);
1202                         forward((int) number, 1, 0);
1203                         break;
1204
1205                 case A_F_FOREVER:
1206                         /*
1207                          * Forward forever, ignoring EOF.
1208                          */
1209                         if (ch_getflags() & CH_HELPFILE)
1210                                 break;
1211                         cmd_exec();
1212                         jump_forw();
1213                         ignore_eoi = 1;
1214                         while (!sigs)
1215                         {
1216                                 make_display();
1217                                 forward(1, 0, 0);
1218                         }
1219                         ignore_eoi = 0;
1220                         /*
1221                          * This gets us back in "F mode" after processing
1222                          * a non-abort signal (e.g. window-change).
1223                          */
1224                         if (sigs && !ABORT_SIGS())
1225                                 newaction = A_F_FOREVER;
1226                         break;
1227
1228                 case A_F_SCROLL:
1229                         /*
1230                          * Forward N lines
1231                          * (default same as last 'd' or 'u' command).
1232                          */
1233                         if (number > 0)
1234                                 wscroll = (int) number;
1235                         cmd_exec();
1236                         if (show_attn == OPT_ONPLUS)
1237                                 set_attnpos(bottompos);
1238                         forward(wscroll, 0, 0);
1239                         break;
1240
1241                 case A_B_SCROLL:
1242                         /*
1243                          * Forward N lines
1244                          * (default same as last 'd' or 'u' command).
1245                          */
1246                         if (number > 0)
1247                                 wscroll = (int) number;
1248                         cmd_exec();
1249                         backward(wscroll, 0, 0);
1250                         break;
1251
1252                 case A_FREPAINT:
1253                         /*
1254                          * Flush buffers, then repaint screen.
1255                          * Don't flush the buffers on a pipe!
1256                          */
1257                         clear_buffers();
1258                         /* FALLTHRU */
1259                 case A_REPAINT:
1260                         /*
1261                          * Repaint screen.
1262                          */
1263                         cmd_exec();
1264                         repaint();
1265                         break;
1266
1267                 case A_GOLINE:
1268                         /*
1269                          * Go to line N, default beginning of file.
1270                          */
1271                         if (number <= 0)
1272                                 number = 1;
1273                         cmd_exec();
1274                         jump_back(number);
1275                         break;
1276
1277                 case A_PERCENT:
1278                         /*
1279                          * Go to a specified percentage into the file.
1280                          */
1281                         if (number < 0)
1282                         {
1283                                 number = 0;
1284                                 fraction = 0;
1285                         }
1286                         if (number > 100)
1287                         {
1288                                 number = 100;
1289                                 fraction = 0;
1290                         }
1291                         cmd_exec();
1292                         jump_percent((int) number, fraction);
1293                         break;
1294
1295                 case A_GOEND:
1296                         /*
1297                          * Go to line N, default end of file.
1298                          */
1299                         cmd_exec();
1300                         if (number <= 0)
1301                                 jump_forw();
1302                         else
1303                                 jump_back(number);
1304                         break;
1305
1306                 case A_GOPOS:
1307                         /*
1308                          * Go to a specified byte position in the file.
1309                          */
1310                         cmd_exec();
1311                         if (number < 0)
1312                                 number = 0;
1313                         jump_line_loc((POSITION) number, jump_sline);
1314                         break;
1315
1316                 case A_STAT:
1317                         /*
1318                          * Print file name, etc.
1319                          */
1320                         if (ch_getflags() & CH_HELPFILE)
1321                                 break;
1322                         cmd_exec();
1323                         parg.p_string = eq_message();
1324                         error("%s", &parg);
1325                         break;
1326
1327                 case A_VERSION:
1328                         /*
1329                          * Print version number, without the "@(#)".
1330                          */
1331                         cmd_exec();
1332                         dispversion();
1333                         break;
1334
1335                 case A_QUIT:
1336                         /*
1337                          * Exit.
1338                          */
1339                         if (curr_ifile != NULL_IFILE &&
1340                             ch_getflags() & CH_HELPFILE)
1341                         {
1342                                 /*
1343                                  * Quit while viewing the help file
1344                                  * just means return to viewing the
1345                                  * previous file.
1346                                  */
1347                                 hshift = save_hshift;
1348                                 if (edit_prev(1) == 0)
1349                                         break;
1350                         }
1351                         if (extra != NULL)
1352                                 quit(*extra);
1353                         quit(QUIT_OK);
1354                         break;
1355
1356 /*
1357  * Define abbreviation for a commonly used sequence below.
1358  */
1359 #define DO_SEARCH() \
1360                         if (number <= 0) number = 1;    \
1361                         mca_search();                   \
1362                         cmd_exec();                     \
1363                         multi_search((char *)NULL, (int) number);
1364
1365
1366                 case A_F_SEARCH:
1367                         /*
1368                          * Search forward for a pattern.
1369                          * Get the first char of the pattern.
1370                          */
1371                         search_type = SRCH_FORW;
1372                         if (number <= 0)
1373                                 number = 1;
1374                         mca_search();
1375                         c = getcc();
1376                         goto again;
1377
1378                 case A_B_SEARCH:
1379                         /*
1380                          * Search backward for a pattern.
1381                          * Get the first char of the pattern.
1382                          */
1383                         search_type = SRCH_BACK;
1384                         if (number <= 0)
1385                                 number = 1;
1386                         mca_search();
1387                         c = getcc();
1388                         goto again;
1389
1390                 case A_FILTER:
1391 #if HILITE_SEARCH
1392                         search_type = SRCH_FORW | SRCH_FILTER;
1393                         mca_search();
1394                         c = getcc();
1395                         goto again;
1396 #else
1397                         error("Command not available", NULL_PARG);
1398                         break;
1399 #endif
1400
1401                 case A_AGAIN_SEARCH:
1402                         /*
1403                          * Repeat previous search.
1404                          */
1405                         DO_SEARCH();
1406                         break;
1407
1408                 case A_T_AGAIN_SEARCH:
1409                         /*
1410                          * Repeat previous search, multiple files.
1411                          */
1412                         search_type |= SRCH_PAST_EOF;
1413                         DO_SEARCH();
1414                         break;
1415
1416                 case A_REVERSE_SEARCH:
1417                         /*
1418                          * Repeat previous search, in reverse direction.
1419                          */
1420                         save_search_type = search_type;
1421                         search_type = SRCH_REVERSE(search_type);
1422                         DO_SEARCH();
1423                         search_type = save_search_type;
1424                         break;
1425
1426                 case A_T_REVERSE_SEARCH:
1427                         /*
1428                          * Repeat previous search,
1429                          * multiple files in reverse direction.
1430                          */
1431                         save_search_type = search_type;
1432                         search_type = SRCH_REVERSE(search_type);
1433                         search_type |= SRCH_PAST_EOF;
1434                         DO_SEARCH();
1435                         search_type = save_search_type;
1436                         break;
1437
1438                 case A_UNDO_SEARCH:
1439                         undo_search();
1440                         break;
1441
1442                 case A_HELP:
1443                         /*
1444                          * Help.
1445                          */
1446                         if (ch_getflags() & CH_HELPFILE)
1447                                 break;
1448                         cmd_exec();
1449                         save_hshift = hshift;
1450                         hshift = 0;
1451                         (void) edit(FAKE_HELPFILE);
1452                         break;
1453
1454                 case A_EXAMINE:
1455 #if EXAMINE
1456                         /*
1457                          * Edit a new file.  Get the filename.
1458                          */
1459                         if (secure)
1460                         {
1461                                 error("Command not available", NULL_PARG);
1462                                 break;
1463                         }
1464                         start_mca(A_EXAMINE, "Examine: ", ml_examine, 0);
1465                         c = getcc();
1466                         goto again;
1467 #else
1468                         error("Command not available", NULL_PARG);
1469                         break;
1470 #endif
1471
1472                 case A_VISUAL:
1473                         /*
1474                          * Invoke an editor on the input file.
1475                          */
1476 #if EDITOR
1477                         if (secure)
1478                         {
1479                                 error("Command not available", NULL_PARG);
1480                                 break;
1481                         }
1482                         if (ch_getflags() & CH_HELPFILE)
1483                                 break;
1484                         if (strcmp(get_filename(curr_ifile), "-") == 0)
1485                         {
1486                                 error("Cannot edit standard input", NULL_PARG);
1487                                 break;
1488                         }
1489                         if (curr_altfilename != NULL)
1490                         {
1491                                 error("WARNING: This file was viewed via LESSOPEN",
1492                                         NULL_PARG);
1493                         }
1494                         start_mca(A_SHELL, "!", ml_shell, 0);
1495                         /*
1496                          * Expand the editor prototype string
1497                          * and pass it to the system to execute.
1498                          * (Make sure the screen is displayed so the
1499                          * expansion of "+%lm" works.)
1500                          */
1501                         make_display();
1502                         cmd_exec();
1503                         lsystem(pr_expand(editproto, 0), (char*)NULL);
1504                         break;
1505 #else
1506                         error("Command not available", NULL_PARG);
1507                         break;
1508 #endif
1509
1510                 case A_NEXT_FILE:
1511                         /*
1512                          * Examine next file.
1513                          */
1514 #if TAGS
1515                         if (ntags())
1516                         {
1517                                 error("No next file", NULL_PARG);
1518                                 break;
1519                         }
1520 #endif
1521                         if (number <= 0)
1522                                 number = 1;
1523                         if (edit_next((int) number))
1524                         {
1525                                 if (get_quit_at_eof() && eof_displayed() &&
1526                                     !(ch_getflags() & CH_HELPFILE))
1527                                         quit(QUIT_OK);
1528                                 parg.p_string = (number > 1) ? "(N-th) " : "";
1529                                 error("No %snext file", &parg);
1530                         }
1531                         break;
1532
1533                 case A_PREV_FILE:
1534                         /*
1535                          * Examine previous file.
1536                          */
1537 #if TAGS
1538                         if (ntags())
1539                         {
1540                                 error("No previous file", NULL_PARG);
1541                                 break;
1542                         }
1543 #endif
1544                         if (number <= 0)
1545                                 number = 1;
1546                         if (edit_prev((int) number))
1547                         {
1548                                 parg.p_string = (number > 1) ? "(N-th) " : "";
1549                                 error("No %sprevious file", &parg);
1550                         }
1551                         break;
1552
1553                 case A_NEXT_TAG:
1554 #if TAGS
1555                         if (number <= 0)
1556                                 number = 1;
1557                         tagfile = nexttag((int) number);
1558                         if (tagfile == NULL)
1559                         {
1560                                 error("No next tag", NULL_PARG);
1561                                 break;
1562                         }
1563                         if (edit(tagfile) == 0)
1564                         {
1565                                 POSITION pos = tagsearch();
1566                                 if (pos != NULL_POSITION)
1567                                         jump_loc(pos, jump_sline);
1568                         }
1569 #else
1570                         error("Command not available", NULL_PARG);
1571 #endif
1572                         break;
1573
1574                 case A_PREV_TAG:
1575 #if TAGS
1576                         if (number <= 0)
1577                                 number = 1;
1578                         tagfile = prevtag((int) number);
1579                         if (tagfile == NULL)
1580                         {
1581                                 error("No previous tag", NULL_PARG);
1582                                 break;
1583                         }
1584                         if (edit(tagfile) == 0)
1585                         {
1586                                 POSITION pos = tagsearch();
1587                                 if (pos != NULL_POSITION)
1588                                         jump_loc(pos, jump_sline);
1589                         }
1590 #else
1591                         error("Command not available", NULL_PARG);
1592 #endif
1593                         break;
1594
1595                 case A_INDEX_FILE:
1596                         /*
1597                          * Examine a particular file.
1598                          */
1599                         if (number <= 0)
1600                                 number = 1;
1601                         if (edit_index((int) number))
1602                                 error("No such file", NULL_PARG);
1603                         break;
1604
1605                 case A_REMOVE_FILE:
1606                         if (ch_getflags() & CH_HELPFILE)
1607                                 break;
1608                         old_ifile = curr_ifile;
1609                         new_ifile = getoff_ifile(curr_ifile);
1610                         if (new_ifile == NULL_IFILE)
1611                         {
1612                                 bell();
1613                                 break;
1614                         }
1615                         if (edit_ifile(new_ifile) != 0)
1616                         {
1617                                 reedit_ifile(old_ifile);
1618                                 break;
1619                         }
1620                         del_ifile(old_ifile);
1621                         break;
1622
1623                 case A_OPT_TOGGLE:
1624                         optflag = OPT_TOGGLE;
1625                         optgetname = FALSE;
1626                         mca_opt_toggle();
1627                         c = getcc();
1628                         goto again;
1629
1630                 case A_DISP_OPTION:
1631                         /*
1632                          * Report a flag setting.
1633                          */
1634                         optflag = OPT_NO_TOGGLE;
1635                         optgetname = FALSE;
1636                         mca_opt_toggle();
1637                         c = getcc();
1638                         goto again;
1639
1640                 case A_FIRSTCMD:
1641                         /*
1642                          * Set an initial command for new files.
1643                          */
1644                         start_mca(A_FIRSTCMD, "+", (void*)NULL, 0);
1645                         c = getcc();
1646                         goto again;
1647
1648                 case A_SHELL:
1649                         /*
1650                          * Shell escape.
1651                          */
1652 #if SHELL_ESCAPE
1653                         if (secure)
1654                         {
1655                                 error("Command not available", NULL_PARG);
1656                                 break;
1657                         }
1658                         start_mca(A_SHELL, "!", ml_shell, 0);
1659                         c = getcc();
1660                         goto again;
1661 #else
1662                         error("Command not available", NULL_PARG);
1663                         break;
1664 #endif
1665
1666                 case A_SETMARK:
1667                         /*
1668                          * Set a mark.
1669                          */
1670                         if (ch_getflags() & CH_HELPFILE)
1671                                 break;
1672                         start_mca(A_SETMARK, "mark: ", (void*)NULL, 0);
1673                         c = getcc();
1674                         if (c == erase_char || c == erase2_char ||
1675                             c == kill_char || c == '\n' || c == '\r')
1676                                 break;
1677                         setmark(c);
1678                         break;
1679
1680                 case A_GOMARK:
1681                         /*
1682                          * Go to a mark.
1683                          */
1684                         start_mca(A_GOMARK, "goto mark: ", (void*)NULL, 0);
1685                         c = getcc();
1686                         if (c == erase_char || c == erase2_char ||
1687                             c == kill_char || c == '\n' || c == '\r')
1688                                 break;
1689                         cmd_exec();
1690                         gomark(c);
1691                         break;
1692
1693                 case A_PIPE:
1694 #if PIPEC
1695                         if (secure)
1696                         {
1697                                 error("Command not available", NULL_PARG);
1698                                 break;
1699                         }
1700                         start_mca(A_PIPE, "|mark: ", (void*)NULL, 0);
1701                         c = getcc();
1702                         if (c == erase_char || c == erase2_char || c == kill_char)
1703                                 break;
1704                         if (c == '\n' || c == '\r')
1705                                 c = '.';
1706                         if (badmark(c))
1707                                 break;
1708                         pipec = c;
1709                         start_mca(A_PIPE, "!", ml_shell, 0);
1710                         c = getcc();
1711                         goto again;
1712 #else
1713                         error("Command not available", NULL_PARG);
1714                         break;
1715 #endif
1716
1717                 case A_B_BRACKET:
1718                 case A_F_BRACKET:
1719                         start_mca(action, "Brackets: ", (void*)NULL, 0);
1720                         c = getcc();
1721                         goto again;
1722
1723                 case A_LSHIFT:
1724                         if (number > 0)
1725                                 shift_count = number;
1726                         else
1727                                 number = (shift_count > 0) ?
1728                                         shift_count : sc_width / 2;
1729                         if (number > hshift)
1730                                 number = hshift;
1731                         hshift -= number;
1732                         screen_trashed = 1;
1733                         break;
1734
1735                 case A_RSHIFT:
1736                         if (number > 0)
1737                                 shift_count = number;
1738                         else
1739                                 number = (shift_count > 0) ?
1740                                         shift_count : sc_width / 2;
1741                         hshift += number;
1742                         screen_trashed = 1;
1743                         break;
1744
1745                 case A_PREFIX:
1746                         /*
1747                          * The command is incomplete (more chars are needed).
1748                          * Display the current char, so the user knows
1749                          * what's going on, and get another character.
1750                          */
1751                         if (mca != A_PREFIX)
1752                         {
1753                                 cmd_reset();
1754                                 start_mca(A_PREFIX, " ", (void*)NULL,
1755                                         CF_QUIT_ON_ERASE);
1756                                 (void) cmd_char(c);
1757                         }
1758                         c = getcc();
1759                         goto again;
1760
1761                 case A_NOACTION:
1762                         break;
1763
1764                 default:
1765                         bell();
1766                         break;
1767                 }
1768         }
1769 }