1: /* Keyboard input; editor command loop.
   2:    Copyright (C) 1985 Richard M. Stallman.
   3: 
   4: This file is part of GNU Emacs.
   5: 
   6: GNU Emacs is distributed in the hope that it will be useful,
   7: but WITHOUT ANY WARRANTY.  No author or distributor
   8: accepts responsibility to anyone for the consequences of using it
   9: or for whether it serves any particular purpose or works at all,
  10: unless he says so in writing.  Refer to the GNU Emacs General Public
  11: License for full details.
  12: 
  13: Everyone is granted permission to copy, modify and redistribute
  14: GNU Emacs, but only under the conditions described in the
  15: GNU Emacs General Public License.   A copy of this license is
  16: supposed to have been given to you along with GNU Emacs so you
  17: can know your rights and responsibilities.  It should be in a
  18: file named COPYING.  Among other things, the copyright notice
  19: and this notice must be preserved on all copies.  */
  20: 
  21: /* Allow config.h to undefine symbols found here.  */
  22: #include <signal.h>
  23: 
  24: #include "config.h"
  25: #include <stdio.h>
  26: #undef NULL
  27: #include "termchar.h"
  28: #include "termopts.h"
  29: #include "termhooks.h"
  30: #include "lisp.h"
  31: #include "macros.h"
  32: #include "window.h"
  33: #include "commands.h"
  34: #include "buffer.h"
  35: #include <setjmp.h>
  36: 
  37: /* Get FIONREAD, if it is available.  */
  38: #ifdef USG
  39: #include <termio.h>
  40: #include <fcntl.h>
  41: #else /* not USG */
  42: #include <sys/ioctl.h>
  43: #endif /* not USG */
  44: 
  45: /* Following definition copied from eval.c */
  46: 
  47: struct backtrace
  48:   {
  49:     struct backtrace *next;
  50:     Lisp_Object *function;
  51:     Lisp_Object *args;  /* Points to vector of args. */
  52:     int nargs;      /* length of vector */
  53:            /* if nargs is UNEVALLED, args points to slot holding list of unevalled args */
  54:     char evalargs;
  55:   };
  56: 
  57: /* Non-nil disable property on a command means
  58:  do not execute it; call disabled-command-hook's value instead. */
  59: Lisp_Object Qdisabled, Vdisabled_command_hook;
  60: 
  61: int recent_keys_index;  /* Index for storing next element into recent_keys */
  62: int total_keys;     /* Total number of elements stored into recent_keys */
  63: char recent_keys[100];  /* Holds last 100 keystrokes */
  64: 
  65: extern struct backtrace *backtrace_list;
  66: 
  67: static jmp_buf getcjmp; /* for longjmp to where kbd input is being done. */
  68: 
  69: int waiting_for_input;  /* True while doing kbd input */
  70: 
  71: static int echoing; /* True while inside EchoKeys.  Delays C-g throwing. */
  72: 
  73: int immediate_quit; /* Nonzero means C-G should cause immediate error-signal. */
  74: 
  75: int help_char;      /* Character to recognize as the help char.  */
  76: 
  77: Lisp_Object Vhelp_form; /* Form to execute when help char is typed.  */
  78: 
  79: extern struct Lisp_Vector *CurrentGlobalMap;
  80: 
  81: /* Total number of times get_char has returned.  */
  82: 
  83: int num_input_chars;
  84: 
  85: /* Last input character read as a command.  */
  86: 
  87: int last_command_char;
  88: 
  89: /* Last input character read for any purpose.  */
  90: 
  91: int last_input_char;
  92: 
  93: /* If not -1, a character to be read as the next command input */
  94: 
  95: int unread_command_char;
  96: 
  97: /* Char to use as prefix when a meta character is typed in.
  98:  This is bound on entry to minibuffer in case Esc is changed there.  */
  99: 
 100: int meta_prefix_char;
 101: 
 102: static auto_save_interval;  /* The number of keystrokes between
 103: 				   auto-saves. */
 104: static Keystrokes;      /* The number of keystrokes since the last
 105: 				   auto-save. */
 106: 
 107: Lisp_Object last_command;   /* Previous command, represented by a Lisp object.
 108: 				   Does not include prefix commands and arg setting commands */
 109: 
 110: Lisp_Object this_command;   /* If a command sets this,
 111: 				   the value goes into previous-command for the next command. */
 112: 
 113: Lisp_Object Qself_insert_command;
 114: Lisp_Object Qforward_char;
 115: Lisp_Object Qbackward_char;
 116: 
 117: /* read_key_sequence stores here the command definition of the
 118:  key sequence that it reads */
 119: Lisp_Object read_key_sequence_cmd;
 120: 
 121: /* Form to evaluate (if non-nil) when Emacs is started */
 122: Lisp_Object Vtop_level;
 123: 
 124: /* User-supplied string to translate input characters through */
 125: Lisp_Object Vkeyboard_translate_table;
 126: 
 127: FILE *dribble;          /* File in which we write all commands we read */
 128: 
 129: /* Nonzero if input is available */
 130: int input_pending;
 131: 
 132: /* Nonzero if should obey 0200 bit in input chars as "Meta" */
 133: int MetaFlag;
 134: 
 135: /* Buffer for pre-read keyboard input */
 136: unsigned char kbd_buffer [256];
 137: 
 138: /* Number of characters available in kbd_buffer.  */
 139: int kbd_count;
 140: 
 141: /* Pointer to next available character in kbd_buffer.  */
 142: unsigned char *kbd_ptr;
 143: 
 144: /* Address (if not 0) of word to zero out
 145:  if a SIGIO interrupt happens */
 146: long *input_available_clear_word;
 147: 
 148: /* Nonzero means use SIGIO interrupts; zero means use CBREAK mode.
 149:    Default is 1 if INTERRUPT_INPUT is defined.  */
 150: 
 151: int interrupt_input;
 152: 
 153: /* nonzero means use ^S/^Q for flow control.  */
 154: 
 155: int flow_control;
 156: 
 157: #ifndef BSD4_1
 158: #define sigfree() sigsetmask (0)
 159: #define sigholdx(sig) sigsetmask (1 << ((sig) - 1))
 160: #define sigblockx(sig) sigblock (1 << ((sig) - 1))
 161: #define sigunblockx(sig) sigblock (0)
 162: #define sigpausex(sig) sigpause (0)
 163: #endif /* not BSD4_1 */
 164: 
 165: #ifdef BSD4_1
 166: #define SIGIO SIGTINT
 167: /* sigfree and sigholdx are in sysdep.c */
 168: #define sigblockx(sig) sighold (sig)
 169: #define sigunblockx(sig) sigrelse (sig)
 170: #define sigpausex(sig) sigpause (sig)
 171: #endif /* BSD4_1 */
 172: 
 173: static char KeyBuf[10];     /* Buffer for keys from get_char () */
 174: static NextK;           /* Next index into KeyBuf */
 175: static echo_keystrokes;     /* True iff we are to echo keystrokes */
 176: static Echo1;           /* Stuff for final echo */
 177: unsigned char *keys_prompt; /* String to display in front of echoed keystrokes, or 0 */
 178: 
 179: #define min(a,b)    ((a)<(b)?(a):(b))
 180: 
 181: static char echobuf[100];
 182: 
 183: EchoThem (notfinal)
 184:      register notfinal;
 185: {
 186:   char *p;
 187:   int i;
 188: 
 189:   extern char *push_key_description ();
 190: 
 191:   if (!(keys_prompt || (echo_keystrokes && NextK)))
 192:     /* (!(echo_keystrokes && (NextK || keys_prompt)) */
 193:     return;
 194: 
 195:   echoing = 1;
 196:   p = echobuf;
 197:   if (keys_prompt)
 198:     {
 199:       strcpy (p, keys_prompt);
 200:       p += strlen (p);
 201:     }
 202:   for (i = 0; i < NextK; i++)
 203:     {
 204:       p = push_key_description (KeyBuf[i], p);
 205:       *p++ = ' ';
 206:       if (i == 0 && KeyBuf[0] == help_char)
 207:     {
 208:       strcpy (p, "(Type ? for further options) ");
 209:       p += strlen (p);
 210:     }
 211:     }
 212:   if (notfinal && NextK
 213:       && !(NextK == 1 && KeyBuf[0] == help_char))
 214:     p[-1] = '-';
 215:   *p = 0;
 216:   minibuf_message = echobuf;
 217: 
 218:   if (notfinal)
 219:     Echo1++;        /* set echoed-flag */
 220:   if (notfinal >= 0)
 221:     DoDsp (0);
 222: 
 223:   echoing = 0;
 224: 
 225:   if (waiting_for_input && !NULL (Vquit_flag))
 226:     quit_throw_to_get_char ();
 227: }
 228: 
 229: Lisp_Object recursive_edit_unwind (), command_loop ();
 230: Lisp_Object cmd_error ();
 231: Lisp_Object top_level_1 ();
 232: 
 233: DEFUN ("recursive-edit", Frecursive_edit, Srecursive_edit, 0, 0, "",
 234:   "Invoke the editor command loop recursively.\n\
 235: Do (throw 'exit nil) within the command loop to make this function return,\n\
 236: or (throw 'exit t) to make this function signal an error.\n\
 237: This function is called by the editor initialization\n\
 238: to begin editing.")
 239:   ()
 240: {
 241:   int count = specpdl_ptr - specpdl;
 242:   Lisp_Object val;
 243: 
 244:   RecurseDepth++;
 245:   RedoModes++;
 246: 
 247:   record_unwind_protect (recursive_edit_unwind,
 248:              (RecurseDepth &&
 249:               bf_cur != XBUFFER (XWINDOW (selected_window)->buffer))
 250:              ? Fcurrent_buffer ()
 251:              : Qnil);
 252: 
 253:   if (!RecurseDepth)
 254:     internal_condition_case (top_level_1, Qerror, cmd_error);
 255: 
 256:   while (1)
 257:     {
 258:       val = internal_condition_case (command_loop, Qerror, cmd_error);
 259:       /* Value is number if returned due to cmd_error.
 260: 	 In that case, just loop around.  */
 261:       if (NULL (val))
 262:     break;
 263:       if (EQ (val, Qt))
 264:     Fsignal (Qquit, Qnil);
 265:     }
 266: 
 267:   unbind_to (count);
 268:   return Qnil;
 269: }
 270: 
 271: Lisp_Object
 272: recursive_edit_unwind (buffer)
 273:      Lisp_Object buffer;
 274: {
 275:   if (!NULL (buffer))
 276:     Fset_buffer (buffer);
 277:   RecurseDepth--;
 278:   RedoModes++;
 279:   return Qnil;
 280: }
 281: 
 282: Lisp_Object
 283: cmd_error (data)
 284:      Lisp_Object data;
 285: {
 286:   Lisp_Object errmsg, tail, errname, file_error;
 287:   int i;
 288: 
 289:   Vquit_flag = Qnil;
 290:   Vinhibit_quit = Qt;
 291:   Vstandard_input = Qt;
 292:   Vstandard_output = Qt;
 293:   Vexecuting_macro = Qnil;
 294:   minibuf_message = 0;
 295: 
 296:   Fdiscard_input ();
 297:   Ding ();
 298: 
 299:   errname = Fcar (data);
 300: 
 301:   if (EQ (errname, Qerror))
 302:     {
 303:       data = Fcdr (data);
 304:       if (!LISTP (data)) data = Qnil;
 305:       errmsg = Fcar (data);
 306:       file_error = Qnil;
 307:     }
 308:   else
 309:     {
 310:       errmsg = Fget (errname, Qerror_message);
 311:       file_error = Fmemq (Qfile_error,
 312:               Fget (errname, Qerror_conditions));
 313:     }
 314: 
 315:   /* Print an error message including the data items.
 316:      This is done by printing it into a scratch buffer
 317:      and then making a copy of the text in the buffer. */
 318: 
 319:   if (!LISTP (data)) data = Qnil;
 320:   tail = Fcdr (data);
 321: 
 322:   /* For file-error, make error message by concatenating
 323:      all the data items.  They are all strings.  */
 324:   if (!NULL (file_error))
 325:     errmsg = XCONS (tail)->car, tail = XCONS (tail)->cdr;
 326: 
 327:   if (XTYPE (errmsg) == Lisp_String)
 328:     Fprinc (errmsg, Qt);
 329:   else
 330:     write_string_1 ("peculiar error", -1, Qt);
 331: 
 332:   for (i = 0; LISTP (tail); tail = Fcdr (tail), i++)
 333:     {
 334:       write_string_1 (i ? ", " : ": ", 2, Qt);
 335:       if (!NULL (file_error))
 336:     Fprinc (Fcar (tail), Qt);
 337:       else
 338:     Fprin1 (Fcar (tail), Qt);
 339:     }
 340: 
 341:   /* In -batch mode, force out the error message and newlines after it */
 342:   if (noninteractive)
 343:     message ("");
 344: 
 345:   Vquit_flag = Qnil;
 346: 
 347:   Vinhibit_quit = Qnil;
 348:   return make_number (0);
 349: }
 350: 
 351: void
 352: debugger (sig, data)
 353:      Lisp_Object sig, data;
 354: {
 355:   Fterpri (Qnil);
 356:   Fprinc (Fget (sig, Qerror_message), Qnil);
 357:   putchar (' ');
 358:   Fprin1 (data, Qnil);
 359:   Fterpri (Qnil);
 360:   abort ();
 361: }
 362: 
 363: Lisp_Object command_loop_1 ();
 364: 
 365: /* Entry to editor-command-loop.
 366:    This level has the catches for exiting/returning to editor command loop.
 367:    It returns nil to exit recursive edit, t to abort it.  */
 368: 
 369: Lisp_Object
 370: command_loop ()
 371: {
 372:   if (RecurseDepth)
 373:     {
 374:       return internal_catch (Qexit, command_loop_1, Qnil);
 375:     }
 376:   else
 377:     {
 378:       while (1)
 379:     {
 380:       internal_catch (Qtop_level, command_loop_1, Qnil);
 381:       top_level_1 ();
 382:     }
 383:     }
 384: }
 385: 
 386: Lisp_Object
 387: top_level_1 ()
 388: {
 389:   /* On entry to the outer level, run the startup file */
 390:   if (!NULL (Vtop_level))
 391:     Feval (Vtop_level);
 392:   else if (!NULL (Vpurify_flag))
 393:     message ("Bare impure Emacs (standard Lisp code not loaded)");
 394:   else
 395:     message ("Bare Emacs (standard Lisp code not loaded)");
 396:   return Qnil;
 397: }
 398: 
 399: DEFUN ("top-level", Ftop_level, Stop_level, 0, 0, "",
 400:   "Exit all recursive editing levels.")
 401:   ()
 402: {
 403:   Fthrow (Qtop_level, Qnil);
 404: }
 405: 
 406: DEFUN ("exit-recursive-edit", Fexit_recursive_edit, Sexit_recursive_edit, 0, 0, "",
 407:   "Exit from the innermost recursive edit or minibuffer.")
 408:   ()
 409: {
 410:   if (RecurseDepth)
 411:     Fthrow (Qexit, Qnil);
 412:   error ("No recursive edit is in progress");
 413: }
 414: 
 415: DEFUN ("abort-recursive-edit", Fabort_recursive_edit, Sabort_recursive_edit, 0, 0, "",
 416:   "Abort the command that requested this recursive edit or minibuffer input.")
 417:   ()
 418: {
 419:   if (RecurseDepth)
 420:     Fthrow (Qexit, Qt);
 421:   error ("No recursive edit is in progress");
 422: }
 423: 
 424: /* This is the actual command reading loop,
 425:  sans error-handling encapsulation */
 426: 
 427: Lisp_Object Fcommand_execute ();
 428: 
 429: Lisp_Object
 430: command_loop_1 ()
 431: {
 432:   Lisp_Object cmd;
 433:   int lose;
 434:   int nonundocount;
 435:   char keybuf[30];
 436:   int i;
 437: 
 438:   Vprefix_arg = Qnil;
 439:   waiting_for_input = 0;
 440:   Echo1 = 0;
 441:   NextK = 0;
 442:   Vstandard_input = Qt;
 443:   Vstandard_output = Qt;
 444:   last_command = Qt;
 445:   nonundocount = 0;
 446: 
 447:   while (1)
 448:     {
 449: #ifdef C_ALLOCA
 450:       alloca (0);       /* Cause a garbage collection now */
 451:                 /* Since we can free the most stuff here.  */
 452: #endif /* C_ALLOCA */
 453: 
 454:       /* Install chars successfully executed in kbd macro */
 455: 
 456:       if (defining_kbd_macro)
 457:     finalize_kbd_macro_chars ();
 458: 
 459:       /* Make sure current window's buffer is selected.  */
 460: 
 461:       if (XBUFFER (XWINDOW (selected_window)->buffer) != bf_cur)
 462:     SetBfp (XBUFFER (XWINDOW (selected_window)->buffer));
 463: 
 464:       /* If minibuffer on and echo area in use,
 465: 	 wait 2 sec and redraw minibufer.  */
 466: 
 467:       if (MinibufDepth && minibuf_message)
 468:     {
 469:       Fsit_for (make_number (2));
 470:       minibuf_message = 0;
 471:       if (!NULL (Vquit_flag))
 472:         {
 473:           Vquit_flag = Qnil;
 474:           unread_command_char = Ctl ('g');
 475:         }
 476:     }
 477: 
 478:       /* Read next key sequence; i gets its length.  */
 479: 
 480:       i = read_key_sequence (keybuf, sizeof keybuf, 0);
 481:       if (!i)           /* End of file -- happens only in */
 482:     return Qnil;        /* a kbd macro, at the end */
 483: 
 484:       last_command_char = keybuf[i - 1];
 485: 
 486:       cmd = read_key_sequence_cmd;
 487:       if (!NULL (Vexecuting_macro))
 488:     {
 489:       if (!NULL (Vquit_flag))
 490:         {
 491:           Vexecuting_macro = Qt;
 492:           QUIT;     /* Make some noise. */
 493:                 /* Will return since macro now empty. */
 494:         }
 495:     }
 496: 
 497:       if (NULL (cmd))
 498:     {
 499:       Ding ();
 500:       defining_kbd_macro = 0;
 501:       RedoModes++;
 502:       Vprefix_arg = Qnil;
 503:     }
 504:       else
 505:     {
 506:       this_command = cmd;
 507:       if (NULL (Vprefix_arg))
 508:         {
 509:           if (EQ (cmd, Qforward_char) && point <= NumCharacters)
 510:         {
 511:           lose = CharAt (point);
 512:           SetPoint (point + 1);
 513:           if (lose >= ' ' && lose < 0177
 514:               && (XFASTINT (XWINDOW (selected_window)->last_modified)
 515:               >= bf_modified)
 516:               && (XFASTINT (XWINDOW (selected_window)->last_point)
 517:               == point)
 518:               && !windows_or_buffers_changed
 519:               && !detect_input_pending ()
 520:               && NULL (Vexecuting_macro))
 521:             direct_output_forward_char (1);
 522:           goto directly_done;
 523:         }
 524:           else if (EQ (cmd, Qbackward_char) && point > FirstCharacter)
 525:         {
 526:           SetPoint (point - 1);
 527:           lose = CharAt (point);
 528:           if (lose >= ' ' && lose < 0177
 529:               && (XFASTINT (XWINDOW (selected_window)->last_modified)
 530:               >= bf_modified)
 531:               && (XFASTINT (XWINDOW (selected_window)->last_point)
 532:               == point)
 533:               && !windows_or_buffers_changed
 534:               && !detect_input_pending ()
 535:               && NULL (Vexecuting_macro))
 536:             direct_output_forward_char (-1);
 537:           goto directly_done;
 538:         }
 539:           else if (EQ (cmd, Qself_insert_command))
 540:         {
 541:           if (NULL (Vexecuting_macro) &&
 542:               !EQ (minibuf_window, selected_window))
 543:             {
 544:               if (!nonundocount || nonundocount >= 20)
 545:             {
 546:               Fundo_boundary ();
 547:               nonundocount = 0;
 548:             }
 549:               nonundocount++;
 550:             }
 551:           lose = (XFASTINT (XWINDOW (selected_window)->last_modified)
 552:               < bf_modified)
 553:             || (XFASTINT (XWINDOW (selected_window)->last_point)
 554:               != point)
 555:             || bf_modified <= bf_cur->save_modified
 556:             || windows_or_buffers_changed
 557:             || detect_input_pending ()
 558:             || !NULL (Vexecuting_macro);
 559:           if (SelfInsert (last_command_char))
 560:             {
 561:               lose = 1;
 562:               nonundocount = 0;
 563:             }
 564:           if (!lose
 565:               && (point == NumCharacters + 1 || CharAt (point) == '\n')
 566:               && last_command_char >= ' '
 567:               && last_command_char < 0177)
 568:             direct_output_for_insert (last_command_char);
 569:           goto directly_done;
 570:         }
 571:         }
 572: 
 573:       /* Here for a command that isn't executed directly */
 574: 
 575:       nonundocount = 0;
 576:       if (NULL (Vprefix_arg) && NULL (Vexecuting_macro) &&
 577:           !EQ (minibuf_window, selected_window))
 578:         Fundo_boundary ();
 579:       Fcommand_execute (cmd, Qnil);
 580: 
 581:     directly_done: ;
 582:     }
 583: 
 584:       if (NULL (Vprefix_arg))
 585:     {
 586:       last_command = this_command;
 587:       NextK = 0;
 588:       Echo1 = 0;
 589:     }
 590:     }
 591: }
 592: 
 593: /* Input of single characters from keyboard */
 594: 
 595: Lisp_Object print_help ();
 596: 
 597: int echo_flag;
 598: int echo_now;
 599: 
 600: /* Alarm interrupt calls this and requests echoing at earliest safe time. */
 601: request_echo ()
 602: {
 603:   /* Note: no need to reestablish handler on USG systems
 604:      because it is established, if approriate, each time an alarm is requested.  */
 605: #if defined(BSD4_1) && defined(subprocesses)
 606:   extern int select_alarmed;
 607:   if (select_alarmed == 0)
 608:     {
 609:       select_alarmed = 1;
 610:       sigrelse (SIGALRM);
 611:       return;
 612:     }
 613: #endif
 614: #ifdef BSD4_1
 615:   sigisheld (SIGALRM);
 616: #endif
 617: 
 618:   if (echo_now)
 619:     EchoThem (1);
 620:   else
 621:     echo_flag = 1;
 622: 
 623: #ifdef BSD4_1
 624:   sigunhold (SIGALRM);
 625: #endif
 626: }
 627: 
 628: /* read a character from the keyboard; call the redisplay if needed */
 629: /* commandflag nonzero means auto-saving may be considered */
 630: get_char (commandflag)
 631:      int commandflag;
 632: {
 633:   register int c;
 634:   register alarmtime = echo_keystrokes;
 635:   int count;
 636:   Lisp_Object tem;
 637:   extern request_echo ();
 638: 
 639:   if ((c = unread_command_char) >= 0)
 640:     {
 641:       unread_command_char = -1;
 642:       goto reread;
 643:     }
 644: 
 645:   if (!NULL (Vexecuting_macro))
 646:     {
 647:       if (XTYPE (Vexecuting_macro) != Lisp_String
 648:       || XSTRING (Vexecuting_macro)->size <= executing_macro_index)
 649:     return -1;
 650:       QUIT;
 651:       c = XSTRING (Vexecuting_macro)->data[executing_macro_index++];
 652:       goto from_macro;
 653:     }
 654: 
 655:   if (!input_pending && !detect_input_pending ())
 656:     {
 657:       DoDsp (0);
 658:       if (auto_save_interval > 0 && commandflag
 659:       && Keystrokes > auto_save_interval
 660:       && Keystrokes > 20)
 661:     {
 662:       Fdo_auto_save (Qnil);
 663:       Keystrokes = 0;
 664:     }
 665:     }
 666: 
 667:   Keystrokes++;
 668: 
 669:   if (_setjmp (getcjmp))
 670:     {
 671:       c = Ctl('g');
 672:       waiting_for_input = 0;
 673:       input_available_clear_word = 0;
 674: 
 675:       goto non_reread;
 676:     }
 677: 
 678:   /* If echoing already, we will echo without delay, so need no interrupt */
 679:   /* If no keys accumulated yet, need no interrupt. */
 680:   /* If minibuffer active, do not echo keystrokes. */
 681:   if (Echo1 || !NextK || MinibufDepth)
 682:     alarmtime = 0;
 683:     /* Message turns off echoing unless more keystrokes turn it on again. */
 684:   if (minibuf_message && minibuf_message != echobuf)
 685:     alarmtime = 0, Echo1 = 0, NextK = 0;
 686: 
 687:   if (Echo1)        /* If already echoing, put a dash at the end now */
 688:     EchoThem (1);
 689: 
 690:   /* Else start echoing if user waits more than `alarmtime' seconds. */
 691:   if (alarmtime > 0)
 692:     {
 693:       /* This interrupt either calls EchoThem right away
 694: 	 or sets echo_flag, which causes EchoThem to be called
 695: 	 by set_waiting_for_input's next invocation.  */
 696:       signal (SIGALRM, request_echo);
 697:       echo_flag = 0;
 698:       echo_now = 0;
 699:       alarm ((unsigned) alarmtime);
 700:     }
 701: 
 702: #ifdef DEBUG
 703:   /* This should be impossible, but I suspect it happens.  */
 704:   if (getcjmp[0] == 0)
 705:     abort ();
 706: #endif /* DEBUG */
 707: 
 708:   c = kbd_buffer_get_char ();
 709: 
 710:  non_reread:
 711: 
 712: #ifdef DEBUG
 713:   /* Cause immediate crash if anyone tries to throw back to this frame
 714:      beyond here.  */
 715:   getcjmp[0] = 0;
 716: #endif /* DEBUG */
 717: 
 718:   /* Cancel alarm if it was set and has not already gone off. */
 719:   if (alarmtime > 0) alarm (0);
 720: 
 721:   minibuf_message = 0;
 722: 
 723:   if (c < 0) return -1;
 724: 
 725:   c &= MetaFlag ? 0377 : 0177;
 726: 
 727:   if (XTYPE (Vkeyboard_translate_table) == Lisp_String
 728:       && XSTRING (Vkeyboard_translate_table)->size > c)
 729:     c = XSTRING (Vkeyboard_translate_table)->data[c];
 730: 
 731:   total_keys++;
 732:   recent_keys[recent_keys_index] = c;
 733:   recent_keys_index = (recent_keys_index + 1) % sizeof recent_keys;
 734: 
 735:   if (dribble)
 736:     {
 737:       putc (c, dribble);
 738:       fflush (dribble);
 739:     }
 740: 
 741:   store_kbd_macro_char (c);
 742: 
 743:  from_macro:
 744:   if (NextK < sizeof KeyBuf)
 745:     KeyBuf[NextK++] = c;
 746: 
 747:   /* If already echoing, echo right away. */
 748:   if (Echo1)
 749:     EchoThem (0);
 750: 
 751:  reread:
 752:   /* If the first character of a command is being reread,
 753:      store it in case a pause follows and it must be echoed later.
 754:      This has no effect on a non-reread character
 755:      since NextK is not zero here for them.  */
 756:   if (NextK == 0)
 757:     KeyBuf[NextK++] = c;
 758: 
 759:   last_input_char = c;
 760: 
 761:   num_input_chars++;
 762: 
 763:   /* Process the help character specially if enabled */
 764:   if (c == help_char && !NULL (Vhelp_form))
 765:     {
 766:       count = specpdl_ptr - specpdl;
 767: 
 768:       record_unwind_protect (save_window_restore, save_window_save ());
 769: 
 770:       tem = Feval (Vhelp_form);
 771:       if (XTYPE (tem) == Lisp_String)
 772:     internal_with_output_to_temp_buffer ("*Help*", print_help, tem);
 773: 
 774:       NextK = 0;
 775:       c = get_char (0);
 776:       /* Remove the help from the screen */
 777:       unbind_to (count);
 778:       DoDsp (0);
 779:       if (c == 040)
 780:     {
 781:       NextK = 0;
 782:       c = get_char (0);
 783:     }
 784:     }
 785: 
 786:   return c;
 787: }
 788: 
 789: Lisp_Object
 790: print_help (object)
 791:      Lisp_Object object;
 792: {
 793:   Fprinc (object, Qnil);
 794:   return Qnil;
 795: }
 796: 
 797: /* Low level keyboard input.
 798:  Read characters into kbd_buffer
 799:  from which they are obtained by kbd_buffer_get_char.  */
 800: 
 801: kbd_buffer_get_char ()
 802: {
 803:   register int c;
 804:   int nread;
 805: 
 806:   if (noninteractive)
 807:     {
 808:       c = getchar ();
 809:       if (c < 0)        /* In batch mode, die at input eof */
 810:     Fkill_emacs (Qt);
 811:       return c;
 812:     }
 813: 
 814:   /* Either ordinary input buffer or C-g buffered means we can return.  */
 815:   while (!kbd_count)
 816:     {
 817:       if (!NULL (Vquit_flag))
 818:     quit_throw_to_get_char ();
 819: 
 820: #ifdef SIGIO
 821:       gobble_input ();
 822: #endif /* SIGIO */
 823:       if (!kbd_count)
 824:     {
 825: #ifdef subprocesses
 826:       wait_reading_process_input (0, -1, 1);
 827: #else
 828: #ifdef SIGIO
 829:       if (interrupt_input)
 830:         {
 831:           sigblockx (SIGIO);
 832:           set_waiting_for_input (0);
 833:           while (!kbd_count)
 834:         sigpausex (SIGIO);
 835:           clear_waiting_for_input ();
 836:           sigunblockx (SIGIO);
 837:         }
 838: #else
 839:       interrupt_input = 0;
 840: #endif /* not SIGIO */
 841: #endif /* subprocesses */
 842: 
 843:       if (!interrupt_input && !kbd_count)
 844:         {
 845:           read_avail_input ();
 846:         }
 847:     }
 848:     }
 849: 
 850:   input_pending = --kbd_count > 0;
 851:   c = *kbd_ptr;         /* *kbd_ptr++ would have a timing error. */
 852:   kbd_ptr++;            /* See kbd_buffer_store_char. */
 853:   return c & 0377;      /* Clean up if sign was extended. */
 854: }
 855: 
 856: /* Store into *addr the number of terminal input chars available.
 857:    Equivalent to ioctl (0, FIONREAD, addr) but works
 858:    even if FIONREAD does not exist.  */
 859: 
 860: get_input_pending (addr)
 861:      int *addr;
 862: {
 863: #ifdef FIONREAD
 864:   if (ioctl (0, FIONREAD, addr) < 0)
 865:     *addr = 0;
 866: #else /* no FIONREAD */
 867:   read_avail_input ();
 868:   *addr = kbd_count;
 869: #endif /* no FIONREAD */
 870: }
 871: 
 872: /* Read any terminal input already buffered up by the system
 873:    into the kbd_buffer, assuming the buffer is currently empty.  */
 874: 
 875: read_avail_input ()
 876: {
 877: #ifdef FIONREAD
 878:   int nread;
 879:   get_input_pending (&nread);
 880:   if (nread > sizeof kbd_buffer)
 881:     nread = sizeof kbd_buffer;
 882:   if (!nread)
 883:     nread = 1;
 884:   set_waiting_for_input (0);
 885:   kbd_count = read (0, kbd_buffer, nread);
 886:   clear_waiting_for_input ();
 887:   kbd_ptr = kbd_buffer;
 888: #else /* no FIONREAD */
 889: #ifdef USG
 890:   /* Assume this is only done when the buffer is empty.
 891:      It's stupid to call this function without checking kbd_count.  */
 892:   if (kbd_count)
 893:     abort ();
 894: 
 895:   fcntl (fileno (stdin), F_SETFL, O_NDELAY);
 896:   kbd_ptr = kbd_buffer;
 897:   kbd_count = read (fileno (stdin), kbd_buffer, sizeof kbd_buffer);
 898:   fcntl (fileno (stdin), F_SETFL, 0);
 899: #else /* not USG */
 900:   you lose
 901: #endif /* not USG */
 902: #endif /* no FIONREAD */
 903: }
 904: 
 905: #ifdef SIGIO   /* for entire page */
 906: 
 907: gobble_input ()
 908: {
 909:   int nread;
 910:   if (interrupt_input)
 911:     {
 912:       get_input_pending (&nread);
 913:       if (nread)
 914:     {
 915:       sigholdx (SIGIO);
 916:       input_available_signal (SIGIO);
 917:       sigfree ();
 918:     }
 919:     }
 920: }
 921: 
 922: /* Set this for debugging, to have a way to get out */
 923: int stop_character;
 924: 
 925: /* Store a character obtained at interrupt level into kbd_buffer, fifo */
 926: kbd_buffer_store_char (c)
 927:      int c;
 928: {
 929:   if (!MetaFlag)
 930:     c &= 0177;
 931:   else
 932:     c &= 0377;
 933: 
 934:   if (c == 07)
 935:     {
 936:       interrupt_signal ();
 937:       return;
 938:     }
 939: 
 940:   if (c && c == stop_character)
 941:     {
 942: #ifdef SIGTSTP          /* Support possible in later USG versions */
 943:       kill (getpid (), SIGTSTP);
 944: #else
 945:       fake_suspend ();
 946: #endif /* not SIGTSTP */
 947:       return;
 948:     }
 949: 
 950:   if (kbd_ptr != kbd_buffer)
 951:     {
 952:       bcopy (kbd_ptr, kbd_buffer, kbd_count);
 953:       kbd_ptr = kbd_buffer;
 954:     }
 955: 
 956:   if (kbd_count < sizeof kbd_buffer)
 957:     {
 958:       kbd_buffer[kbd_count++] = c;
 959:     }
 960: }
 961: 
 962: input_available_signal (signo)
 963:      int signo;
 964: {
 965:   unsigned char buf[64];
 966:   int nread;
 967:   register int i;
 968: #ifdef BSD4_1
 969:   extern int select_alarmed;
 970: #endif
 971: 
 972: #ifdef USG
 973:   /* USG systems forget handlers when they are used;
 974:      must reestablish each time */
 975:   signal (signo, input_available_signal);
 976: #endif /* USG */
 977: 
 978: #ifdef BSD4_1
 979:   sigisheld (SIGIO);
 980: #endif
 981: 
 982:   if (input_available_clear_word)
 983:     *input_available_clear_word = 0;
 984: 
 985:   while (1)
 986:     {
 987:       get_input_pending (&nread);
 988:       if (nread <= 0)
 989:     break;
 990: #ifdef BSD4_1
 991:       select_alarmed = 1;  /* Force the select emulator back to life */
 992: #endif
 993:       if (read_socket_hook)
 994:     {
 995:       nread = (*read_socket_hook) (0, buf, sizeof buf);
 996:       if (!nread)
 997:         continue;
 998:     }
 999:       else
1000:     {
1001:       if (nread > sizeof buf)
1002:         nread = sizeof buf;
1003:       nread = read (0, buf, nread);
1004:     }
1005: 
1006:       for (i = 0; i < nread; i++)
1007:     {
1008:       kbd_buffer_store_char (buf[i]);
1009:       /* Don't look at input that follows a C-g too closely.
1010: 	     This reduces lossage due to autorepeat on C-g.  */
1011:       if (buf[i] == Ctl('G'))
1012:         break;
1013:     }
1014:     }
1015: #ifdef BSD4_1
1016:   sigfree ();
1017: #endif
1018: }
1019: #endif /* SIGIO */
1020: 
1021: /* Read a sequence of keys that ends with a non prefix character,
1022:  and store them in keybuf, a buffer of size bufsize.
1023:  Prompt with `prompt'.  Echo starting immediately unless `prompt' is 0.
1024:  Return the length of the key sequence stored.
1025: */
1026: 
1027: int
1028: read_key_sequence (keybuf, bufsize, prompt)
1029:      char *keybuf;
1030:      unsigned char *prompt;
1031: {
1032:   register int i;
1033:   Lisp_Object nextlocal, nextglobal;
1034:   register int c, nextc;
1035:   Lisp_Object local, global;
1036: 
1037:   keys_prompt = prompt;
1038: 
1039:   if (prompt)
1040:     NextK = 0;
1041:   if (prompt && INTERACTIVE)
1042:     EchoThem (1);
1043: 
1044:   nextlocal = bf_cur->keymap;
1045:   XSET (nextglobal, Lisp_Vector, CurrentGlobalMap);
1046: 
1047:   i = 0;
1048:   nextc = -1;
1049:   while (!NULL (nextlocal) || !NULL (nextglobal))
1050:     {
1051:       if (i == bufsize)
1052:     error ("key sequence too long");
1053: 
1054:       if (nextc >= 0)
1055:     {
1056:       c = nextc;
1057:       nextc = -1;
1058:     }
1059:       else
1060:     c = get_char (!prompt);
1061:       Vquit_flag = Qnil;
1062: 
1063:       if (c < 0)
1064:     return 0;
1065:       if (c >= 0200)
1066:     {
1067:       nextc = c & 0177;
1068:       c = meta_prefix_char;
1069:     }
1070: 
1071:       keybuf[i++] = c;
1072: 
1073:       global = !NULL (nextglobal)
1074:     ? get_keyelt (access_keymap (nextglobal, c))
1075:       : Qnil;
1076: 
1077:       local = !NULL (nextlocal)
1078:     ? get_keyelt (access_keymap (nextlocal, c))
1079:       : Qnil;
1080: 
1081:       nextlocal = Qnil;
1082:       nextglobal = Qnil;
1083: 
1084:       read_key_sequence_cmd = !NULL (local) ? local : global;
1085: 
1086:       /* trace symbols to their function definitions */
1087: 
1088:       while (XTYPE (global) == Lisp_Symbol && !NULL (global)
1089:          && !EQ (global, Qunbound))
1090:     global = XSYMBOL (global)->function;
1091:       while (XTYPE (local) == Lisp_Symbol && !NULL (local)
1092:          && !EQ (local, Qunbound))
1093:     local = XSYMBOL (local)->function;
1094: 
1095:       /* Are the definitions prefix characters? */
1096: 
1097:       if (XTYPE (local) == Lisp_Vector ||
1098:       (LISTP (local) && EQ (XCONS (local)->car, Qkeymap))
1099:       ||
1100:       /* If nextc is set, we are processing a prefix char
1101: 	     that represents a meta-bit.
1102: 	     Let a global prefix definition override a local non-prefix.
1103: 	     This is for minibuffers that redefine Escape for completion.
1104: 	     A real Escape gets completion, but Meta bits get ESC-prefix.  */
1105:       ((NULL (local) || nextc >= 0)
1106:        && (XTYPE (global) == Lisp_Vector ||
1107:            (LISTP (global) && EQ (XCONS (global)->car, Qkeymap)))))
1108:     {
1109:       if (XTYPE (local) == Lisp_Vector ||
1110:           (LISTP (local) && EQ (XCONS (local)->car, Qkeymap)))
1111:         nextlocal = local;
1112:       else
1113:         nextlocal = Qnil;
1114: 
1115:       if (XTYPE (global) == Lisp_Vector ||
1116:           (LISTP (global) && EQ (XCONS (global)->car, Qkeymap)))
1117:         nextglobal = global;
1118:       else
1119:         nextglobal = Qnil;
1120:     }
1121:     }
1122: 
1123:   keys_prompt = 0;
1124:   return i;
1125: }
1126: 
1127: DEFUN ("read-key-sequence", Fread_key_sequence, Sread_key_sequence, 1, 1, 0,
1128:   "Read a sequence of keystrokes and return as a string.\n\
1129: The sequence is sufficient to specify a non-prefix command\n\
1130: starting from the current local and global keymaps.\n\
1131: A C-g typed while in this function is treated like\n\
1132: any other character, and quit-flag is not set.\n\
1133: One arg, PROMPT, a prompt string or  nil, meaning do not prompt specially.")
1134:   (prompt)
1135:      Lisp_Object prompt;
1136: {
1137:   char keybuf[30];
1138:   register int i;
1139: 
1140:   if (!NULL (prompt))
1141:     CHECK_STRING (prompt, 0);
1142:   QUIT;
1143:   i = read_key_sequence (keybuf, sizeof keybuf,
1144:              (NULL (prompt)) ? 0 : XSTRING (prompt)->data);
1145:   return make_string (keybuf, i);
1146: }
1147: 
1148: DEFUN ("command-execute", Fcommand_execute, Scommand_execute, 1, 2, 0,
1149:  "Execute CMD as an editor command.\n\
1150: CMD must be a symbol with a function definition;\n\
1151: also, it must satisfy the commandp predicate.")
1152:      (cmd, record)
1153:      Lisp_Object cmd, record;
1154: {
1155:   Lisp_Object final;
1156:   Lisp_Object tem;
1157:   Lisp_Object prefixarg;
1158:   struct backtrace backtrace;
1159: 
1160:   prefixarg = Vprefix_arg, Vprefix_arg = Qnil;
1161:   Vcurrent_prefix_arg = prefixarg;
1162: 
1163:   if (XTYPE (cmd) == Lisp_Symbol)
1164:     {
1165:       tem = Fget (cmd, Qdisabled);
1166:       if (!NULL (tem))
1167:     return Fapply (Vdisabled_command_hook, Qnil);
1168:     }
1169: 
1170:   while (1)
1171:     {
1172:       final = cmd;
1173:       while (XTYPE (final) == Lisp_Symbol)
1174:     {
1175:       if (EQ (Qunbound, XSYMBOL (final)->function))
1176:         Fsymbol_function (final);    /* Get an error! */
1177:       final = XSYMBOL (final)->function;
1178:     }
1179: 
1180:       if (LISTP (final) && (tem = Fcar (final), EQ (tem, Qautoload)))
1181:     do_autoload (final, cmd);
1182:       else
1183:     break;
1184:     }
1185: 
1186:   if (LISTP (final) || XTYPE (final) == Lisp_Subr)
1187:     {
1188:       backtrace.next = backtrace_list;
1189:       backtrace_list = &backtrace;
1190:       backtrace.function = &Qcall_interactively;
1191:       backtrace.args = &cmd;
1192:       backtrace.nargs = 1;
1193:       backtrace.evalargs = 0;
1194: 
1195:       tem = Fcall_interactively (cmd, record);
1196: 
1197:       backtrace_list = backtrace.next;
1198:       return tem;
1199:     }
1200:   if (XTYPE (final) == Lisp_String)
1201:     {
1202:       return Fexecute_kbd_macro (final, prefixarg);
1203:     }
1204:   return Qnil;
1205: }
1206: 
1207: detect_input_pending ()
1208: {
1209:   if (!input_pending)
1210:     {
1211:       if (kbd_count)
1212:     input_pending = kbd_count;
1213:       else
1214:     get_input_pending (&input_pending);
1215:     }
1216:   return input_pending;
1217: }
1218: 
1219: DEFUN ("input-pending-p", Finput_pending_p, Sinput_pending_p, 0, 0, 0,
1220:   "T if command input is currently available with no waiting.\n\
1221: Actually, the value is NIL only if we can be sure that no input is available.")
1222:   ()
1223: {
1224:   if (unread_command_char >= 0) return Qt;
1225: 
1226:   return detect_input_pending () ? Qt : Qnil;
1227: }
1228: 
1229: DEFUN ("recent-keys", Frecent_keys, Srecent_keys, 0, 0, 0,
1230:   "Return string of last 100 chars read from terminal.")
1231:   ()
1232: {
1233:   Lisp_Object val;
1234:   if (total_keys < sizeof recent_keys)
1235:     return make_string (recent_keys, total_keys);
1236: 
1237:   val = make_string (recent_keys, sizeof recent_keys);
1238:   bcopy (recent_keys + recent_keys_index,
1239:      XSTRING (val)->data,
1240:      sizeof recent_keys - recent_keys_index);
1241:   bcopy (recent_keys,
1242:      XSTRING (val)->data + sizeof recent_keys - recent_keys_index,
1243:      recent_keys_index);
1244:   return val;
1245: }
1246: 
1247: DEFUN ("this-command-keys", Fthis_command_keys, Sthis_command_keys, 0, 0, 0,
1248:   "Return string of the keystrokes that invoked this command.")
1249:   ()
1250: {
1251:   return make_string (KeyBuf, NextK);
1252: }
1253: 
1254: DEFSIMPLE ("recursion-depth", Frecursion_depth, Srecursion_depth,
1255:        "Return the current depth in recursive edits.",
1256:        Lisp_Int, XSETINT, RecurseDepth)
1257: 
1258: DEFUN ("open-dribble-file", Fopen_dribble_file, Sopen_dribble_file, 1, 1,
1259:   "FOpen dribble file: ",
1260:   "Start writing all keyboard characters to FILE.")
1261:   (file)
1262:      Lisp_Object file;
1263: {
1264:   file = Fexpand_file_name (file, Qnil);
1265:   dribble = fopen (XSTRING (file)->data, "w");
1266:   return Qnil;
1267: }
1268: 
1269: DEFUN ("discard-input", Fdiscard_input, Sdiscard_input, 0, 0, 0,
1270:   "Discard the contents of the terminal input buffer.\n\
1271: Also flush any kbd macro definition in progress.")
1272:   ()
1273: {
1274:   defining_kbd_macro = 0;
1275:   RedoModes++;
1276: 
1277:   unread_command_char = -1;
1278:   discard_tty_input ();
1279: 
1280:   kbd_count = 0;
1281:   input_pending = 0;
1282: 
1283:   return Qnil;
1284: }
1285: 
1286: DEFUN ("suspend-emacs", Fsuspend_emacs, Ssuspend_emacs, 0, 1, "",
1287:   "Stop Emacs and return to superior process.  You can resume.\n\
1288: If optional arg STUFFSTRING is non-nil, its characters are stuffed\n\
1289: to be read as terminal input by Emacs's superior shell.")
1290:   (stuffstring)
1291:      Lisp_Object stuffstring;
1292: {
1293: #ifdef SIGTSTP          /* Support possible in later USG versions */
1294:   if (!NULL (stuffstring))
1295:     CHECK_STRING (stuffstring, 0);
1296: 
1297:   reset_sys_modes ();
1298:   stuff_buffered_input (stuffstring);
1299:   kill (0, SIGTSTP);
1300:   init_sys_modes ();
1301: #else
1302:   fake_suspend ();
1303: #endif
1304:   return Qnil;
1305: }
1306: 
1307: #ifndef SIGTSTP
1308: /* On a system where suspending is not implemented,
1309:    instead fork a subshell and let it talk directly to the terminal
1310:    while we wait.  */
1311: 
1312: fake_suspend ()
1313: {
1314:   int pid = fork ();
1315:   int spid;
1316:   int status;
1317:   char *sh;
1318:   int (*interrupt) ();
1319:   int (*quit) ();
1320:   int (*term) ();
1321:   unsigned char *temp;
1322:   int i;
1323: 
1324:   if (pid == -1)
1325:     error ("Can't spawn subshell");
1326:   if (pid == 0)
1327:     {
1328:       sh = (char *) getenv ("SHELL");
1329:       if (sh == 0)
1330:     sh = "sh";
1331:       /* Use our buffer's default directory for the subshell.  */
1332:       if (XTYPE (bf_cur->directory) == Lisp_String)
1333:     {
1334:       temp = (unsigned char *) alloca (XSTRING (bf_cur->directory)->size + 2);
1335:       bcopy (XSTRING (bf_cur->directory)->data, temp,
1336:          XSTRING (bf_cur->directory)->size);
1337:       i = XSTRING (bf_cur->directory)->size;
1338:       if (temp[i - 1] != '/') temp[i++] = '/';
1339:       temp[i] = 0;
1340:       chdir (temp);
1341:     }
1342:       execlp (sh, sh, 0);
1343:       write (1, "Can't execute subshell", 22);
1344:       _exit (1);
1345:     }
1346:   interrupt = signal (SIGINT, SIG_IGN);
1347:   quit = signal (SIGQUIT, SIG_IGN);
1348:   term = signal (SIGTERM, SIG_IGN);
1349:   reset_sys_modes ();
1350:   wait_for_termination (pid);
1351:   init_sys_modes ();
1352:   signal (SIGINT, interrupt);
1353:   signal (SIGQUIT, quit);
1354:   signal (SIGTERM, term);
1355: }
1356: #endif /* no SIGTSTP */
1357: 
1358: /* If STUFFSTRING is a string, stuff its contents as pending terminal input.
1359:    Then in any case stuff anthing Emacs has read ahead and not used.  */
1360: 
1361: stuff_buffered_input (stuffstring)
1362:      Lisp_Object stuffstring;
1363: {
1364:   register unsigned char *p;
1365:   register int count;
1366: 
1367: /* stuff_char works only in BSD, versions 4.2 and up.  */
1368: #if defined (BSD) && ~defined (BSD4_1)
1369:   if (XTYPE (stuffstring) == Lisp_String)
1370:     {
1371:       p = XSTRING (stuffstring)->data;
1372:       count = XSTRING (stuffstring)->size;
1373:       while (count-- > 0)
1374:     stuff_char (*p++);
1375:       stuff_char ('\n');
1376:     }
1377:   /* Anything we have read ahead, put back for the shell to read.  */
1378:   while (kbd_count)
1379:     {
1380:       stuff_char (*kbd_ptr++);
1381:       kbd_count--;
1382:     }
1383:   input_pending = 0;
1384: #endif /* BSD and not BSD4_1 */
1385: }
1386: 
1387: set_waiting_for_input (word_to_clear)
1388:      long *word_to_clear;
1389: {
1390:   input_available_clear_word = word_to_clear;
1391: 
1392:   /* Tell interrupt_signal to throw back to get_char,  */
1393:   waiting_for_input = 1;
1394: 
1395:   /* If interrupt_signal was called before and buffered a C-g,
1396:      make it run again now, to avoid timing error.  */
1397:   if (!NULL (Vquit_flag))
1398:     quit_throw_to_get_char ();
1399: 
1400:   /* Tell alarm signal to echo right away */
1401:   echo_now = 1;
1402: 
1403:   /* If alarm has gone off already, echo now.  */
1404:   if (echo_flag)
1405:     {
1406:       EchoThem (1);
1407:       echo_flag = 0;
1408:     }
1409: }
1410: 
1411: clear_waiting_for_input ()
1412: {
1413:   /* Tell interrupt_signal not to throw back to get_char,  */
1414:   waiting_for_input = 0;
1415:   echo_now = 0;
1416:   input_available_clear_word = 0;
1417: }
1418: 
1419: /* This routine is called at interrupt level in response to C-G.
1420:  If interrupt_input, this is the handler for SIGINT.
1421:  Otherwise, it is called from kbd_buffer_store_char,
1422:  in handling SIGIO or SIGTINT.
1423: 
1424:  If `waiting_for_input' is non zero, then unless `echoing' is nonzero,
1425:  immediately throw back to get_char.
1426: 
1427:  Otherwise it sets the Lisp variable  quit-flag  not-nil.
1428:  This causes  eval  to throw, when it gets a chance.
1429:  If  quit-flag  is already non-nil, it stops the job right away.  */
1430: 
1431: interrupt_signal ()
1432: {
1433:   char c;
1434: 
1435: #ifdef USG
1436:   /* USG systems forget handlers when they are used;
1437:      must reestablish each time */
1438:   signal (SIGINT, interrupt_signal);
1439:   signal (SIGQUIT, interrupt_signal);
1440: #endif /* USG */
1441: 
1442:   Echo1 = 0;
1443: 
1444:   if (!NULL (Vquit_flag))
1445:     {
1446:       fflush (stdout);
1447:       reset_sys_modes ();
1448:       sigfree ();
1449: #ifdef SIGTSTP          /* Support possible in later USG versions */
1450: /*
1451:  * On systems which can suspend the current process and return to the original
1452:  * shell, this command causes the user to end up back at the shell.
1453:  * The "Auto-save" and "Abort" questions are not asked until
1454:  * the user elects to return to emacs, at which point he can save the current
1455:  * job and either dump core or continue.
1456:  */
1457:       kill (0, SIGTSTP);
1458: #else
1459:       /* Perhaps should really fork an inferior shell?
1460: 	 But that would not provide any way to get back
1461: 	 to the original shell, ever.  */
1462:       printf ("No support for stopping a process in this Unix version;\n");
1463:       printf ("you can continue or abort.\n");
1464: #endif /* not SIGTSTP */
1465:       printf ("Auto-save? (y or n) ");
1466:       fflush (stdout);
1467:       if (((c = getchar ()) & ~040) == 'Y')
1468:     Fdo_auto_save (Qnil);
1469:       while (c != '\n') c = getchar ();
1470:       printf ("Abort (and dump core)? (y or n) ");
1471:       fflush (stdout);
1472:       if (((c = getchar ()) & ~040) == 'Y')
1473:     abort ();
1474:       while (c != '\n') c = getchar ();
1475:       printf ("Continuing...\n");
1476:       fflush (stdout);
1477:       init_sys_modes ();
1478:     }
1479:   else
1480:     {
1481:       /* If executing a function that wants to be interrupted out of
1482: 	     and the user has not deferred quitting by binding `inhibit-quit'
1483: 	     then quit right away.  */
1484:       if (immediate_quit && NULL (Vinhibit_quit))
1485:     {
1486:       immediate_quit = 0;
1487:           sigfree ();
1488:       Fsignal (Qquit, Qnil);
1489:     }
1490:       else
1491:     /* Else request quit when it's safe */
1492:     Vquit_flag = Qt;
1493:     }
1494: 
1495:   if (waiting_for_input && !echoing)
1496:     quit_throw_to_get_char ();
1497: }
1498: 
1499: /* Handle a C-g by making get_char return C-g.  */
1500: 
1501: quit_throw_to_get_char ()
1502: {
1503:   sigfree ();
1504:   /* Prevent another signal from doing this before we finish.  */
1505:   waiting_for_input = 0;
1506:   input_pending = 0;
1507:   unread_command_char = -1;
1508:   _longjmp (getcjmp, 1);
1509: }
1510: 
1511: DEFUN ("set-input-mode", Fset_input_mode, Sset_input_mode, 2, 2, 0,
1512:   "Set mode of reading keyboard input.\n\
1513: First arg non-nil means use input interrupts; nil means use CBREAK mode.\n\
1514: Second arg non-nil means use ^S/^Q flow control\n\
1515:  (no effect except in CBREAK mode).")
1516:   (interrupt, flow)
1517:      Lisp_Object interrupt, flow;
1518: {
1519:   reset_sys_modes ();
1520: #ifdef SIGIO
1521:   interrupt_input = !NULL (interrupt);
1522: #else /* not SIGIO */
1523:   interrupt_input = 0;
1524: #endif /* not SIGIO */
1525:   flow_control = !NULL (flow);
1526:   init_sys_modes ();
1527:   return Qnil;
1528: }
1529: 
1530: init_keyboard ()
1531: {
1532:   RecurseDepth = -1;    /* Correct, before outermost invocation of editor loop */
1533:   keys_prompt = 0;
1534:   immediate_quit = 0;
1535:   unread_command_char = -1;
1536:   recent_keys_index = 0;
1537:   total_keys = 0;
1538:   kbd_count = 0;
1539:   kbd_ptr = kbd_buffer;
1540:   input_pending = 0;
1541:   if (!noninteractive)
1542:     {
1543:       signal (SIGINT, interrupt_signal);
1544: #ifdef USG
1545:       /* On USG systems, C-g is set up for both SIGINT and SIGQUIT
1546: 	 and we can't tell which one it will give us.  */
1547:       signal (SIGQUIT, interrupt_signal);
1548: #endif /* USG */
1549:     }
1550: #ifdef SIGIO
1551:   signal (SIGIO, input_available_signal);
1552: #endif SIGIO
1553: 
1554: /* Use interrupt input by default, if it works and noninterrupt input
1555:    has deficiencies.  */
1556: 
1557: #ifdef INTERRUPT_INPUT
1558:   interrupt_input = 1;
1559: #else
1560:   interrupt_input = 0;
1561: #endif
1562: 
1563:   sigfree ();
1564:   dribble = 0;
1565: }
1566: 
1567: syms_of_keyboard ()
1568: {
1569:   Qself_insert_command = intern ("self-insert-command");
1570:   staticpro (&Qself_insert_command);
1571: 
1572:   Qforward_char = intern ("forward-char");
1573:   staticpro (&Qforward_char);
1574: 
1575:   Qbackward_char = intern ("backward-char");
1576:   staticpro (&Qbackward_char);
1577: 
1578:   Qtop_level = intern ("top-level");
1579:   staticpro (&Qtop_level);
1580: 
1581:   Qdisabled = intern ("disabled");
1582:   staticpro (&Qdisabled);
1583: 
1584:   defsubr (&Sread_key_sequence);
1585:   defsubr (&Srecursive_edit);
1586:   defsubr (&Sinput_pending_p);
1587:   defsubr (&Scommand_execute);
1588:   defsubr (&Srecent_keys);
1589:   defsubr (&Sthis_command_keys);
1590:   defsubr (&Ssuspend_emacs);
1591:   defsubr (&Sabort_recursive_edit);
1592:   defsubr (&Sexit_recursive_edit);
1593:   defsubr (&Srecursion_depth);
1594:   defsubr (&Stop_level);
1595:   defsubr (&Sdiscard_input);
1596:   defsubr (&Sopen_dribble_file);
1597:   defsubr (&Sset_input_mode);
1598: 
1599:   DefLispVar ("disabled-command-hook", &Vdisabled_command_hook,
1600:     "Value is called instead of any command that is disabled\n\
1601: \(has a non-nil  disabled  property).");
1602: 
1603:   DefBoolVar ("meta-flag", &MetaFlag,
1604:     "*Non-nil means treat 0200 bit in terminal input as Meta bit.");
1605: 
1606:   DefIntVar ("last-command-char", &last_command_char,
1607:     "Last terminal input character that was part of a command, as an integer.");
1608: 
1609:   DefIntVar ("last-input-char", &last_input_char,
1610:     "Last terminal input character, as an integer.");
1611: 
1612:   DefIntVar ("unread-command-char", &unread_command_char,
1613:     "Character to be read as next input from command input stream, or -1 if none.");
1614: 
1615:   DefIntVar ("meta-prefix-char", &meta_prefix_char,
1616:     "Meta-prefix character code.  Meta-foo as command input\n\
1617: turns into this character followed by foo.");
1618:   meta_prefix_char = 033;
1619: 
1620:   DefLispVar ("last-command", &last_command,
1621:     "The last command executed.  Normally a symbol with a function definition,\n\
1622: but can be whatever was found in the keymap, or whatever that command left in this-command.");
1623:   last_command = Qnil;
1624: 
1625:   DefLispVar ("this-command", &this_command,
1626:     "The command now being executed.\n\
1627: The command can set this variable; whatever is put here\n\
1628: will be in  last-command  during the following command.");
1629:   this_command = Qnil;
1630: 
1631:   DefIntVar ("auto-save-interval", &auto_save_interval,
1632:     "*Number of keyboard input characters between auto-saves.");
1633:   auto_save_interval = 300;
1634: 
1635:   DefIntVar ("echo-keystrokes", &echo_keystrokes,
1636:     "*Nonzero means echo unfinished commands after this many seconds of pause.");
1637:   echo_keystrokes = 1;
1638: 
1639:   DefIntVar ("help-char", &help_char,
1640:     "Character to recognize as meaning Help.\n\
1641: When it is read, do (eval help-form), and display result if it's a string.\n\
1642: If help-form's value is nil, this char can be read normally.");
1643:   help_char = Ctl ('H');
1644: 
1645:   DefLispVar ("help-form", &Vhelp_form,
1646:     "Form to execute when character help-char is read.\n\
1647: If the form returns a string, that string is displayed.\n\
1648: If help-form is nil, the help char is not recognized.");
1649:   Vhelp_form = Qnil;
1650: 
1651:   DefLispVar ("top-level", &Vtop_level,
1652:     "Form to evaluate when Emacs starts up.\n\
1653: Useful to set before you dump a modified Emacs.");
1654:   Vtop_level = Qnil;
1655: 
1656:   DefLispVar ("keyboard-translate-table", &Vkeyboard_translate_table,
1657:     "String used as translate table for keyboard input, or nil.\n\
1658: Each character is looked up in this string and the contents used instead.\n\
1659: If string is of length N, character codes N and up are untranslated.");
1660:   Vkeyboard_translate_table = Qnil;
1661: }
1662: 
1663: keys_of_keyboard ()
1664: {
1665:   defkey (GlobalMap, Ctl ('Z'), "suspend-emacs");
1666:   defkey (CtlXmap, Ctl ('Z'), "suspend-emacs");
1667:   defkey (ESCmap, Ctl ('C'), "exit-recursive-edit");
1668:   defkey (GlobalMap, Ctl (']'), "abort-recursive-edit");
1669: }

Defined functions

DEFSIMPLE defined in line 1254; never used
DEFUN defined in line 1511; never used
EchoThem defined in line 183; used 5 times
clear_waiting_for_input defined in line 1411; used 3 times
cmd_error defined in line 282; used 3 times
command_loop defined in line 369; used 2 times
command_loop_1 defined in line 429; used 4 times
debugger defined in line 351; used 2 times
fake_suspend defined in line 1312; used 2 times
get_char defined in line 630; used 5 times
get_input_pending defined in line 860; used 4 times
gobble_input defined in line 907; used 2 times
init_keyboard defined in line 1530; used 1 times
input_available_signal defined in line 962; used 3 times
interrupt_signal defined in line 1431; used 5 times
kbd_buffer_get_char defined in line 801; used 1 times
kbd_buffer_store_char defined in line 926; used 1 times
keys_of_keyboard defined in line 1663; used 1 times
print_help defined in line 789; used 2 times
quit_throw_to_get_char defined in line 1501; used 4 times
read_avail_input defined in line 875; used 2 times
read_key_sequence defined in line 1027; used 2 times
recursive_edit_unwind defined in line 271; used 2 times
request_echo defined in line 601; used 2 times
set_waiting_for_input defined in line 1387; used 3 times
stuff_buffered_input defined in line 1361; used 2 times
syms_of_keyboard defined in line 1567; used 1 times
top_level_1 defined in line 386; used 3 times

Defined variables

KeyBuf defined in line 173; used 7 times
MetaFlag defined in line 133; used 4 times
Qbackward_char defined in line 115; used 3 times
Qdisabled defined in line 59; used 3 times
Qforward_char defined in line 114; used 3 times
Qself_insert_command defined in line 113; used 3 times
Vdisabled_command_hook defined in line 59; used 2 times
Vhelp_form defined in line 77; used 4 times
Vkeyboard_translate_table defined in line 125; used 5 times
Vtop_level defined in line 122; used 4 times
echo_flag defined in line 597; used 4 times
echo_now defined in line 598; used 4 times
echobuf defined in line 181; used 3 times
echoing defined in line 71; used 3 times
flow_control defined in line 155; used 1 times
getcjmp defined in line 67; used 4 times
help_char defined in line 75; used 5 times
input_available_clear_word defined in line 146; used 5 times
input_pending defined in line 130; used 10 times
interrupt_input defined in line 151; used 13 times
kbd_buffer defined in line 136; used 13 times
kbd_count defined in line 139; used 18 times
kbd_ptr defined in line 142; used 9 times
keys_prompt defined in line 177; used 6 times
last_command defined in line 107; used 4 times
last_command_char defined in line 87; used 13 times
last_input_char defined in line 91; used 2 times
meta_prefix_char defined in line 100; used 3 times
num_input_chars defined in line 83; used 3 times
read_key_sequence_cmd defined in line 119; used 2 times
recent_keys defined in line 63; used 10 times
recent_keys_index defined in line 61; used 8 times
stop_character defined in line 923; used 1 times
this_command defined in line 110; used 4 times
total_keys defined in line 62; used 4 times
waiting_for_input defined in line 69; used 7 times

Defined struct's

backtrace defined in line 47; used 6 times

Defined macros

SIGIO defined in line 166; used 12 times
min defined in line 179; never used
sigblockx defined in line 168; used 1 times
sigfree defined in line 158; used 6 times
sigholdx defined in line 159; used 1 times
sigpausex defined in line 170; used 1 times
sigunblockx defined in line 169; used 1 times
Last modified: 1986-03-25
Generated: 2016-12-26
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