Annotation of 43BSDReno/contrib/emacs-18.55/src/keyboard.c, revision 1.1

1.1     ! root        1: /* Keyboard input; editor command loop.
        !             2:    Copyright (C) 1985, 1986, 1987, 1988 Free Software Foundation, Inc.
        !             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: /*** For version 19, can simplify this by making interrupt_input 1 on VMS.  */
        !            22: 
        !            23: /* Allow config.h to undefine symbols found here.  */
        !            24: #include <signal.h>
        !            25: 
        !            26: #include "config.h"
        !            27: #include <stdio.h>
        !            28: #undef NULL
        !            29: #include "termchar.h"
        !            30: #include "termopts.h"
        !            31: #include "termhooks.h"
        !            32: #include "lisp.h"
        !            33: #include "macros.h"
        !            34: #include "window.h"
        !            35: #include "commands.h"
        !            36: #include "buffer.h"
        !            37: #include <setjmp.h>
        !            38: #include <errno.h>
        !            39: 
        !            40: extern int errno;
        !            41: 
        !            42: /* Get FIONREAD, if it is available.  */
        !            43: #ifdef USG
        !            44: #include <termio.h>
        !            45: #include <fcntl.h>
        !            46: #else /* not USG */
        !            47: #ifndef VMS
        !            48: #include <sys/ioctl.h>
        !            49: #endif /* not VMS */
        !            50: #endif /* not USG */
        !            51: 
        !            52: /* Allow m- file to inhibit use of FIONREAD.  */
        !            53: #ifdef BROKEN_FIONREAD
        !            54: #undef FIONREAD
        !            55: #endif
        !            56: 
        !            57: /* Make all keyboard buffers much bigger when using X windows.  */
        !            58: #ifdef HAVE_X_WINDOWS
        !            59: #define BUFFER_SIZE_FACTOR 16
        !            60: #else
        !            61: #define BUFFER_SIZE_FACTOR 1
        !            62: #endif
        !            63: 
        !            64: /* Following definition copied from eval.c */
        !            65: 
        !            66: struct backtrace
        !            67:   {
        !            68:     struct backtrace *next;
        !            69:     Lisp_Object *function;
        !            70:     Lisp_Object *args; /* Points to vector of args. */
        !            71:     int nargs;         /* length of vector */
        !            72:               /* if nargs is UNEVALLED, args points to slot holding list of unevalled args */
        !            73:     char evalargs;
        !            74:   };
        !            75: 
        !            76: /* Non-nil disable property on a command means
        !            77:  do not execute it; call disabled-command-hook's value instead. */
        !            78: Lisp_Object Qdisabled, Vdisabled_command_hook;
        !            79: 
        !            80: int recent_keys_index; /* Index for storing next element into recent_keys */
        !            81: int total_keys;                /* Total number of elements stored into recent_keys */
        !            82: char recent_keys[100]; /* Holds last 100 keystrokes */
        !            83: 
        !            84: extern struct backtrace *backtrace_list;
        !            85: 
        !            86: static jmp_buf getcjmp;        /* for longjmp to where kbd input is being done. */
        !            87: 
        !            88: int waiting_for_input; /* True while doing kbd input */
        !            89: 
        !            90: static int echoing;    /* True while inside EchoKeys.  Delays C-g throwing. */
        !            91: 
        !            92: int immediate_quit;    /* Nonzero means C-G should cause immediate error-signal. */
        !            93: 
        !            94: int help_char;         /* Character to recognize as the help char.  */
        !            95: 
        !            96: Lisp_Object Vhelp_form;        /* Form to execute when help char is typed.  */
        !            97: 
        !            98: extern struct Lisp_Vector *CurrentGlobalMap;
        !            99: 
        !           100: /* Total number of times get_char has returned.  */
        !           101: 
        !           102: int num_input_chars;
        !           103: 
        !           104: /* Last input character read as a command.  */
        !           105: 
        !           106: int last_command_char;
        !           107: 
        !           108: /* Last input character read for any purpose.  */
        !           109: 
        !           110: int last_input_char;
        !           111: 
        !           112: /* If not -1, a character to be read as the next command input */
        !           113: 
        !           114: int unread_command_char;
        !           115: 
        !           116: /* Char to use as prefix when a meta character is typed in.
        !           117:  This is bound on entry to minibuffer in case Esc is changed there.  */
        !           118: 
        !           119: int meta_prefix_char;
        !           120: 
        !           121: static int auto_save_interval; /* The number of keystrokes between
        !           122:                                   auto-saves. */
        !           123: static int Keystrokes;         /* The number of keystrokes since the last
        !           124:                                   auto-save. */
        !           125: 
        !           126: Lisp_Object last_command;      /* Previous command, represented by a Lisp object.
        !           127:                                   Does not include prefix commands and arg setting commands */
        !           128: 
        !           129: Lisp_Object this_command;      /* If a command sets this,
        !           130:                                   the value goes into previous-command for the next command. */
        !           131: 
        !           132: Lisp_Object Qself_insert_command;
        !           133: Lisp_Object Qforward_char;
        !           134: Lisp_Object Qbackward_char;
        !           135: 
        !           136: /* read_key_sequence stores here the command definition of the
        !           137:  key sequence that it reads */
        !           138: Lisp_Object read_key_sequence_cmd;
        !           139: 
        !           140: /* Form to evaluate (if non-nil) when Emacs is started */
        !           141: Lisp_Object Vtop_level;
        !           142: 
        !           143: /* User-supplied string to translate input characters through */
        !           144: Lisp_Object Vkeyboard_translate_table;
        !           145: 
        !           146: FILE *dribble;                 /* File in which we write all commands we read */
        !           147: 
        !           148: /* Nonzero if input is available */
        !           149: int input_pending;
        !           150: 
        !           151: /* Nonzero if should obey 0200 bit in input chars as "Meta" */
        !           152: int MetaFlag;
        !           153: 
        !           154: /* Buffer for pre-read keyboard input */
        !           155: unsigned char kbd_buffer [256 * BUFFER_SIZE_FACTOR];
        !           156: 
        !           157: /* Number of characters available in kbd_buffer.  */
        !           158: int kbd_count;
        !           159: 
        !           160: /* Pointer to next available character in kbd_buffer.  */
        !           161: unsigned char *kbd_ptr;
        !           162: 
        !           163: /* Address (if not 0) of word to zero out
        !           164:  if a SIGIO interrupt happens */
        !           165: long *input_available_clear_word;
        !           166: 
        !           167: /* Nonzero means use SIGIO interrupts; zero means use CBREAK mode.
        !           168:    Default is 1 if INTERRUPT_INPUT is defined.  */
        !           169: 
        !           170: int interrupt_input;
        !           171: 
        !           172: /* Nonzero while interrupts are temporarily deferred during redisplay.  */
        !           173: 
        !           174: int interrupts_deferred;
        !           175: 
        !           176: /* nonzero means use ^S/^Q for flow control.  */
        !           177: 
        !           178: int flow_control;
        !           179: 
        !           180: #ifndef BSD4_1
        !           181: #define sigfree() sigsetmask (0)
        !           182: #define sigholdx(sig) sigsetmask (1 << ((sig) - 1))
        !           183: #define sigblockx(sig) sigblock (1 << ((sig) - 1))
        !           184: #define sigunblockx(sig) sigblock (0)
        !           185: #define sigpausex(sig) sigpause (0)
        !           186: #endif /* not BSD4_1 */
        !           187: 
        !           188: #ifdef BSD4_1
        !           189: #define SIGIO SIGTINT
        !           190: /* sigfree and sigholdx are in sysdep.c */
        !           191: #define sigblockx(sig) sighold (sig)
        !           192: #define sigunblockx(sig) sigrelse (sig)
        !           193: #define sigpausex(sig) sigpause (sig)
        !           194: #endif /* BSD4_1 */
        !           195: 
        !           196: #ifndef sigmask
        !           197: #define sigmask(no) (1L << ((no) - 1))
        !           198: #endif
        !           199: 
        !           200: /* We are unable to use interrupts if FIONREAD is not available,
        !           201:    so flush SIGIO so we won't try. */
        !           202: #ifndef FIONREAD
        !           203: #ifdef SIGIO
        !           204: #undef SIGIO
        !           205: #endif
        !           206: #endif
        !           207: 
        !           208: /* Function for init_keyboard to call with no args (if nonzero).  */
        !           209: void (*keyboard_init_hook) ();
        !           210: 
        !           211: static void read_avail_input ();
        !           212: static void get_input_pending ();
        !           213: 
        !           214: /* Non-zero tells input_available_signal to call read_socket_hook
        !           215:    even if FIONREAD returns zero.  */
        !           216: static int force_input;
        !           217: 
        !           218: static char KeyBuf[40];                /* Buffer for keys from get_char () */
        !           219: static int NextK;              /* Next index into KeyBuf */
        !           220: static int echo_keystrokes;    /* > 0 if we are to echo keystrokes */
        !           221: static int Echo1;              /* Stuff for final echo */
        !           222: unsigned char *keys_prompt;    /* String to display in front of echoed keystrokes, or 0 */
        !           223: 
        !           224: #define        min(a,b)        ((a)<(b)?(a):(b))
        !           225: 
        !           226: static char echobuf[100];
        !           227: 
        !           228: EchoThem (notfinal)
        !           229:      register notfinal;
        !           230: {
        !           231:   char *p;
        !           232:   int i;
        !           233: 
        !           234:   extern char *push_key_description ();
        !           235: 
        !           236:   if (!(keys_prompt || (echo_keystrokes > 0 && NextK)))
        !           237:     return;
        !           238: 
        !           239:   echoing = 1;
        !           240:   p = echobuf;
        !           241:   if (keys_prompt)
        !           242:     {
        !           243:       strcpy (p, keys_prompt);
        !           244:       p += strlen (p);
        !           245:     }
        !           246:   for (i = 0; i < NextK; i++)
        !           247:     {
        !           248:       p = push_key_description (KeyBuf[i], p);
        !           249:       *p++ = ' ';
        !           250:       if (i == 0 && KeyBuf[0] == help_char)
        !           251:        {
        !           252:          strcpy (p, "(Type ? for further options) ");
        !           253:          p += strlen (p);
        !           254:        }
        !           255:     }
        !           256:   if (notfinal && NextK
        !           257:       && !(NextK == 1 && KeyBuf[0] == help_char))
        !           258:     p[-1] = '-';
        !           259:   *p = 0;
        !           260:   minibuf_message = echobuf;
        !           261: 
        !           262:   if (notfinal)
        !           263:     Echo1++;           /* set echoed-flag */
        !           264:   if (notfinal >= 0)
        !           265:     DoDsp (0);
        !           266: 
        !           267:   echoing = 0;
        !           268: 
        !           269:   if (waiting_for_input && !NULL (Vquit_flag))
        !           270:     quit_throw_to_get_char ();
        !           271: }
        !           272: 
        !           273: Lisp_Object recursive_edit_unwind (), command_loop ();
        !           274: 
        !           275: DEFUN ("recursive-edit", Frecursive_edit, Srecursive_edit, 0, 0, "",
        !           276:   "Invoke the editor command loop recursively.\n\
        !           277: Do (throw 'exit nil) within the command loop to make this function return,\n\
        !           278: or (throw 'exit t) to make this function signal an error.\n\
        !           279: This function is called by the editor initialization\n\
        !           280: to begin editing.")
        !           281:   ()
        !           282: {
        !           283:   int count = specpdl_ptr - specpdl;
        !           284:   Lisp_Object val;
        !           285: 
        !           286:   RecurseDepth++;
        !           287:   RedoModes++;
        !           288: 
        !           289:   if (RecurseDepth)
        !           290:     {
        !           291:       specbind (Qstandard_output, Qt);
        !           292:       specbind (Qstandard_input, Qt);
        !           293:     }
        !           294: 
        !           295:   record_unwind_protect (recursive_edit_unwind,
        !           296:                         (RecurseDepth &&
        !           297:                          bf_cur != XBUFFER (XWINDOW (selected_window)->buffer))
        !           298:                         ? Fcurrent_buffer ()
        !           299:                         : Qnil);
        !           300: 
        !           301:   val = command_loop ();
        !           302:   if (EQ (val, Qt))
        !           303:     Fsignal (Qquit, Qnil);
        !           304: 
        !           305:   unbind_to (count);
        !           306:   return Qnil;
        !           307: }
        !           308: 
        !           309: Lisp_Object
        !           310: recursive_edit_unwind (buffer)
        !           311:      Lisp_Object buffer;
        !           312: {
        !           313:   if (!NULL (buffer))
        !           314:     Fset_buffer (buffer);
        !           315:   RecurseDepth--;
        !           316:   RedoModes++;
        !           317:   return Qnil;
        !           318: }
        !           319: 
        !           320: Lisp_Object
        !           321: cmd_error (data)
        !           322:      Lisp_Object data;
        !           323: {
        !           324:   Lisp_Object errmsg, tail, errname, file_error;
        !           325:   int i;
        !           326: 
        !           327:   Vquit_flag = Qnil;
        !           328:   Vinhibit_quit = Qt;
        !           329:   Vstandard_output = Qt;
        !           330:   Vstandard_input = Qt;
        !           331:   Vexecuting_macro = Qnil;
        !           332:   minibuf_message = 0;
        !           333: 
        !           334:   Fdiscard_input ();
        !           335:   Ding ();
        !           336: 
        !           337:   errname = Fcar (data);
        !           338: 
        !           339:   if (EQ (errname, Qerror))
        !           340:     {
        !           341:       data = Fcdr (data);
        !           342:       if (!CONSP (data)) data = Qnil;
        !           343:       errmsg = Fcar (data);
        !           344:       file_error = Qnil;
        !           345:     }
        !           346:   else
        !           347:     {
        !           348:       errmsg = Fget (errname, Qerror_message);
        !           349:       file_error = Fmemq (Qfile_error,
        !           350:                          Fget (errname, Qerror_conditions));
        !           351:     }
        !           352: 
        !           353:   /* Print an error message including the data items.
        !           354:      This is done by printing it into a scratch buffer
        !           355:      and then making a copy of the text in the buffer. */
        !           356:   
        !           357:   if (!CONSP (data)) data = Qnil;
        !           358:   tail = Fcdr (data);
        !           359: 
        !           360:   /* For file-error, make error message by concatenating
        !           361:      all the data items.  They are all strings.  */
        !           362:   if (!NULL (file_error))
        !           363:     errmsg = XCONS (tail)->car, tail = XCONS (tail)->cdr;
        !           364: 
        !           365:   if (XTYPE (errmsg) == Lisp_String)
        !           366:     Fprinc (errmsg, Qt);
        !           367:   else
        !           368:     write_string_1 ("peculiar error", -1, Qt);
        !           369: 
        !           370:   for (i = 0; CONSP (tail); tail = Fcdr (tail), i++)
        !           371:     {
        !           372:       write_string_1 (i ? ", " : ": ", 2, Qt);
        !           373:       if (!NULL (file_error))
        !           374:        Fprinc (Fcar (tail), Qt);
        !           375:       else
        !           376:        Fprin1 (Fcar (tail), Qt);
        !           377:     }
        !           378: 
        !           379:   /* In -batch mode, force out the error message and newlines after it
        !           380:      and then die.  */
        !           381:   if (noninteractive)
        !           382:     {
        !           383:       message ("");
        !           384:       Fkill_emacs (make_number (-1));
        !           385:     }
        !           386: 
        !           387:   Vquit_flag = Qnil;
        !           388: 
        !           389:   Vinhibit_quit = Qnil;
        !           390:   return make_number (0);
        !           391: }
        !           392: 
        !           393: Lisp_Object command_loop_1 ();
        !           394: Lisp_Object command_loop_2 ();
        !           395: Lisp_Object cmd_error ();
        !           396: Lisp_Object top_level_1 ();
        !           397: 
        !           398: /* Entry to editor-command-loop.
        !           399:    This level has the catches for exiting/returning to editor command loop.
        !           400:    It returns nil to exit recursive edit, t to abort it.  */
        !           401: 
        !           402: Lisp_Object
        !           403: command_loop ()
        !           404: {
        !           405:   if (RecurseDepth)
        !           406:     {
        !           407:       return internal_catch (Qexit, command_loop_2, Qnil);
        !           408:     }
        !           409:   else
        !           410:     while (1)
        !           411:       {
        !           412:        internal_catch (Qtop_level, top_level_1, Qnil);
        !           413:        internal_catch (Qtop_level, command_loop_2, Qnil);
        !           414:        /* End of file in -batch run causes exit here.  */
        !           415:        if (noninteractive)
        !           416:          Fkill_emacs (Qt);
        !           417:       }
        !           418: }
        !           419: 
        !           420: /* Here we catch errors in execution of commands within the
        !           421:    editing loop, and reenter the editing loop.
        !           422:    When there is an error, cmd_error runs and returns a non-nil
        !           423:    value to us.  A value of nil means that cmd_loop_1 itself
        !           424:    returned due to end of file (or end of kbd macro).  */
        !           425: 
        !           426: Lisp_Object
        !           427: command_loop_2 ()
        !           428: {
        !           429:   register Lisp_Object val;
        !           430:   do
        !           431:     val = internal_condition_case (command_loop_1, Qerror, cmd_error);
        !           432:   while (!NULL (val));
        !           433:   return Qnil;
        !           434: }
        !           435: 
        !           436: Lisp_Object
        !           437: top_level_2 ()
        !           438: {
        !           439:   return Feval (Vtop_level);
        !           440: }
        !           441: 
        !           442: Lisp_Object
        !           443: top_level_1 ()
        !           444: {
        !           445:   /* On entry to the outer level, run the startup file */
        !           446:   if (!NULL (Vtop_level))
        !           447:     internal_condition_case (top_level_2, Qerror, cmd_error);
        !           448:   else if (!NULL (Vpurify_flag))
        !           449:     message ("Bare impure Emacs (standard Lisp code not loaded)");
        !           450:   else
        !           451:     message ("Bare Emacs (standard Lisp code not loaded)");
        !           452:   return Qnil;
        !           453: }
        !           454: 
        !           455: DEFUN ("top-level", Ftop_level, Stop_level, 0, 0, "",
        !           456:   "Exit all recursive editing levels.")
        !           457:   ()
        !           458: {
        !           459:   Fthrow (Qtop_level, Qnil);
        !           460: }
        !           461: 
        !           462: DEFUN ("exit-recursive-edit", Fexit_recursive_edit, Sexit_recursive_edit, 0, 0, "",
        !           463:   "Exit from the innermost recursive edit or minibuffer.")
        !           464:   ()
        !           465: {
        !           466:   if (RecurseDepth)
        !           467:     Fthrow (Qexit, Qnil);
        !           468:   error ("No recursive edit is in progress");
        !           469: }
        !           470: 
        !           471: DEFUN ("abort-recursive-edit", Fabort_recursive_edit, Sabort_recursive_edit, 0, 0, "",
        !           472:   "Abort the command that requested this recursive edit or minibuffer input.")
        !           473:   ()
        !           474: {
        !           475:   if (RecurseDepth)
        !           476:     Fthrow (Qexit, Qt);
        !           477:   error ("No recursive edit is in progress");
        !           478: }
        !           479: 
        !           480: /* This is the actual command reading loop,
        !           481:  sans error-handling encapsulation */
        !           482: 
        !           483: Lisp_Object Fcommand_execute ();
        !           484: 
        !           485: Lisp_Object
        !           486: command_loop_1 ()
        !           487: {
        !           488:   Lisp_Object cmd;
        !           489:   int lose;
        !           490:   int nonundocount;
        !           491:   char keybuf[30];
        !           492:   int i;
        !           493:   int no_redisplay;
        !           494:   int no_direct;
        !           495: 
        !           496:   Vprefix_arg = Qnil;
        !           497:   waiting_for_input = 0;
        !           498:   Echo1 = 0;
        !           499:   NextK = 0;
        !           500:   last_command = Qt;
        !           501:   nonundocount = 0;
        !           502:   no_redisplay = 0;
        !           503:   
        !           504:   while (1)
        !           505:     {
        !           506:       /* Install chars successfully executed in kbd macro */
        !           507:       if (defining_kbd_macro && NULL (Vprefix_arg))
        !           508:        finalize_kbd_macro_chars ();
        !           509: 
        !           510:       /* Make sure current window's buffer is selected.  */
        !           511: 
        !           512:       if (XBUFFER (XWINDOW (selected_window)->buffer) != bf_cur)
        !           513:        SetBfp (XBUFFER (XWINDOW (selected_window)->buffer));
        !           514: 
        !           515:       no_direct = 0;
        !           516: 
        !           517:       /* If minibuffer on and echo area in use,
        !           518:         wait 2 sec and redraw minibufer.  */
        !           519: 
        !           520:       if (MinibufDepth && minibuf_message)
        !           521:        {
        !           522:          Fsit_for (make_number (2), Qnil);
        !           523:          minibuf_message = 0;
        !           524:          no_direct = 1;
        !           525:          if (!NULL (Vquit_flag))
        !           526:            {
        !           527:              Vquit_flag = Qnil;
        !           528:              unread_command_char = Ctl ('g');
        !           529:            }
        !           530:        }
        !           531: 
        !           532:       i = 0;
        !           533: #if 0
        !           534:       /* If prev. command was directly displayed, we don't need
        !           535:         redisplay.  Try shortcut for reading single-char key sequence.  */
        !           536:       if (no_redisplay)
        !           537:        i = fast_read_one_key (keybuf);
        !           538: #endif /* 0 */
        !           539:       /* Shortcut not applicable or found a prefix key.
        !           540:         Take full precautions and read key sequence the hard way.  */
        !           541:       if (i == 0)
        !           542:        {
        !           543: #ifdef C_ALLOCA
        !           544:          alloca (0);           /* Cause a garbage collection now */
        !           545:                                /* Since we can free the most stuff here.  */
        !           546: #endif /* C_ALLOCA */
        !           547: 
        !           548:          /* Read next key sequence; i gets its length.  */
        !           549: 
        !           550:          i = read_key_sequence (keybuf, sizeof keybuf, 0,
        !           551:                                 no_redisplay && buffer_shared <= 1);
        !           552:        }
        !           553: 
        !           554:       /* Now we have read a key sequence of length I,
        !           555:         or else I is 0 and we found end of file.  */
        !           556: 
        !           557:       if (i == 0)              /* End of file -- happens only in */
        !           558:        return Qnil;            /* a kbd macro, at the end */
        !           559: 
        !           560:       last_command_char = keybuf[i - 1];
        !           561:       
        !           562:       cmd = read_key_sequence_cmd;
        !           563:       if (!NULL (Vexecuting_macro))
        !           564:        {
        !           565:          if (!NULL (Vquit_flag))
        !           566:            {
        !           567:              Vexecuting_macro = Qt;
        !           568:              QUIT;             /* Make some noise. */
        !           569:                                /* Will return since macro now empty. */
        !           570:            }
        !           571:        }
        !           572: 
        !           573:       /* Do redisplay processing after this command except in special
        !           574:         cases identified below that set no_redisplay to 1.  */
        !           575:       no_redisplay = 0;
        !           576: 
        !           577:       /* Execute the command.  */
        !           578: 
        !           579:       if (NULL (cmd))
        !           580:        {
        !           581:          /* nil means key is undefined.  */
        !           582:          Ding ();
        !           583:          defining_kbd_macro = 0;
        !           584:          RedoModes++;
        !           585:          Vprefix_arg = Qnil;
        !           586:        }
        !           587:       else
        !           588:        {
        !           589:          this_command = cmd;
        !           590:          if (NULL (Vprefix_arg) && ! no_direct)
        !           591:            {
        !           592:              if (EQ (cmd, Qforward_char) && point <= NumCharacters)
        !           593:                {
        !           594:                  lose = CharAt (point);
        !           595:                  SetPoint (point + 1);
        !           596:                  if (lose >= ' ' && lose < 0177
        !           597:                      && (XFASTINT (XWINDOW (selected_window)->last_modified)
        !           598:                          >= bf_modified)
        !           599:                      && (XFASTINT (XWINDOW (selected_window)->last_point)
        !           600:                          == point)
        !           601:                      && !windows_or_buffers_changed
        !           602:                      && EQ (bf_cur->selective_display, Qnil)
        !           603:                      && !detect_input_pending ()
        !           604:                      && NULL (Vexecuting_macro))
        !           605:                    no_redisplay = direct_output_forward_char (1);
        !           606:                  goto directly_done;
        !           607:                }
        !           608:              else if (EQ (cmd, Qbackward_char) && point > FirstCharacter)
        !           609:                {
        !           610:                  SetPoint (point - 1);
        !           611:                  lose = CharAt (point);
        !           612:                  if (lose >= ' ' && lose < 0177
        !           613:                      && (XFASTINT (XWINDOW (selected_window)->last_modified)
        !           614:                          >= bf_modified)
        !           615:                      && (XFASTINT (XWINDOW (selected_window)->last_point)
        !           616:                          == point)
        !           617:                      && !windows_or_buffers_changed
        !           618:                      && EQ (bf_cur->selective_display, Qnil)
        !           619:                      && !detect_input_pending ()
        !           620:                      && NULL (Vexecuting_macro))
        !           621:                    no_redisplay = direct_output_forward_char (-1);
        !           622:                  goto directly_done;
        !           623:                }
        !           624:              else if (EQ (cmd, Qself_insert_command))
        !           625:                {
        !           626:                  if (NULL (Vexecuting_macro) &&
        !           627:                      !EQ (minibuf_window, selected_window))
        !           628:                    {
        !           629:                      if (!nonundocount || nonundocount >= 20)
        !           630:                        {
        !           631:                          Fundo_boundary ();
        !           632:                          nonundocount = 0;
        !           633:                        }
        !           634:                      nonundocount++;
        !           635:                    }
        !           636:                  lose = (XFASTINT (XWINDOW (selected_window)->last_modified)
        !           637:                          < bf_modified)
        !           638:                    || (XFASTINT (XWINDOW (selected_window)->last_point)
        !           639:                          != point)
        !           640:                    || bf_modified <= bf_cur->save_modified
        !           641:                    || windows_or_buffers_changed
        !           642:                    || !EQ (bf_cur->selective_display, Qnil)
        !           643:                    || detect_input_pending ()
        !           644:                    || !NULL (Vexecuting_macro);
        !           645:                  if (SelfInsert (last_command_char, 0))
        !           646:                    {
        !           647:                      lose = 1;
        !           648:                      nonundocount = 0;
        !           649:                    }
        !           650:                  if (!lose
        !           651:                      && (point == NumCharacters + 1 || CharAt (point) == '\n')
        !           652:                      && last_command_char >= ' '
        !           653:                      && last_command_char < 0177)
        !           654:                    no_redisplay
        !           655:                      = direct_output_for_insert (last_command_char);
        !           656:                  goto directly_done;
        !           657:                }
        !           658:            }
        !           659: 
        !           660:          /* Here for a command that isn't executed directly */
        !           661: 
        !           662:          nonundocount = 0;
        !           663:          if (NULL (Vprefix_arg) && NULL (Vexecuting_macro) &&
        !           664:              !EQ (minibuf_window, selected_window))
        !           665:            Fundo_boundary ();
        !           666:          Fcommand_execute (cmd, Qnil);
        !           667: 
        !           668:        directly_done: ;
        !           669:        }
        !           670: 
        !           671:       if (NULL (Vprefix_arg))
        !           672:        {
        !           673:          last_command = this_command;
        !           674:          NextK = 0;
        !           675:          Echo1 = 0;
        !           676:        }
        !           677:     }
        !           678: }
        !           679: 
        !           680: /* Input of single characters from keyboard */
        !           681: 
        !           682: Lisp_Object print_help ();
        !           683: 
        !           684: int echo_flag;
        !           685: int echo_now;
        !           686: 
        !           687: /* Alarm interrupt calls this and requests echoing at earliest safe time. */
        !           688: request_echo ()
        !           689: {
        !           690:   int old_errno = errno;
        !           691: 
        !           692:   /* Note: no need to reestablish handler on USG systems
        !           693:      because it is established, if approriate, each time an alarm is requested.  */
        !           694: #ifdef subprocesses
        !           695: #ifdef BSD4_1
        !           696:   extern int select_alarmed;
        !           697:   if (select_alarmed == 0)
        !           698:     {
        !           699:       select_alarmed = 1;
        !           700:       sigrelse (SIGALRM);
        !           701:       return;
        !           702:     }
        !           703: #endif
        !           704: #endif
        !           705: 
        !           706: #ifdef BSD4_1
        !           707:   sigisheld (SIGALRM);
        !           708: #endif
        !           709: 
        !           710:   if (echo_now)
        !           711:     EchoThem (1);
        !           712:   else
        !           713:     echo_flag = 1;
        !           714: 
        !           715: #ifdef BSD4_1
        !           716:   sigunhold (SIGALRM);
        !           717: #endif
        !           718: 
        !           719:   errno = old_errno;
        !           720: }
        !           721: 
        !           722: /* read a character from the keyboard; call the redisplay if needed */
        !           723: /* commandflag 0 means do not do auto-saving, but do do redisplay.
        !           724:    -1 means do not do redisplay, but do do autosaving.
        !           725:    1 means do both.  */
        !           726: 
        !           727: get_char (commandflag)
        !           728:      int commandflag;
        !           729: {
        !           730:   register int c;
        !           731:   int alarmtime;
        !           732:   int count;
        !           733:   Lisp_Object tem;
        !           734:   extern request_echo ();
        !           735: 
        !           736:   if ((c = unread_command_char) >= 0)
        !           737:     {
        !           738:       unread_command_char = -1;
        !           739:       goto reread;
        !           740:     }
        !           741: 
        !           742:   if (!NULL (Vexecuting_macro))
        !           743:     {
        !           744:       if (XTYPE (Vexecuting_macro) != Lisp_String
        !           745:          || XSTRING (Vexecuting_macro)->size <= executing_macro_index)
        !           746:        return -1;
        !           747:       QUIT;
        !           748:       c = XSTRING (Vexecuting_macro)->data[executing_macro_index++];
        !           749:       goto from_macro;
        !           750:     }
        !           751: 
        !           752:   if (commandflag >= 0 && !input_pending && !detect_input_pending ())
        !           753:     DoDsp (0);
        !           754: 
        !           755:   if (commandflag != 0
        !           756:       && auto_save_interval > 0
        !           757:       && Keystrokes > auto_save_interval
        !           758:       && Keystrokes > 20
        !           759:       && !input_pending && !detect_input_pending ())
        !           760:     {
        !           761:       Fdo_auto_save (Qnil);
        !           762:       Keystrokes = 0;
        !           763:     }
        !           764: 
        !           765:   Keystrokes++;
        !           766: 
        !           767:   if (_setjmp (getcjmp))
        !           768:     {
        !           769:       c = Ctl('g');
        !           770:       waiting_for_input = 0;
        !           771:       input_available_clear_word = 0;
        !           772: 
        !           773:       goto non_reread;
        !           774:     }
        !           775: 
        !           776:   /* Message turns off echoing unless more keystrokes turn it on again. */
        !           777:   if (minibuf_message && *minibuf_message && minibuf_message != echobuf)
        !           778:     Echo1 = 0, NextK = 0;
        !           779: 
        !           780:   /* If already echoing, continue.  */
        !           781:   else if (Echo1 != 0 /*|| cursor_in_echo_area*/ )
        !           782:     EchoThem (1);
        !           783: 
        !           784:   /* If in middle of key sequence and minibuffer not active,
        !           785:      start echoing if enough time elapses.  */
        !           786:   else if (MinibufDepth == 0 && NextK != 0 && echo_keystrokes > 0)
        !           787:     {
        !           788:       /* Else start echoing if user waits more than `alarmtime' seconds. */
        !           789:       /* This interrupt either calls EchoThem right away
        !           790:         or sets echo_flag, which causes EchoThem to be called
        !           791:         by set_waiting_for_input's next invocation.  */
        !           792:       signal (SIGALRM, request_echo);
        !           793:       echo_flag = 0;
        !           794:       echo_now = 0;
        !           795:       alarmtime = echo_keystrokes;
        !           796:       alarm ((unsigned) alarmtime);
        !           797:     }
        !           798: 
        !           799:   c = kbd_buffer_get_char ();
        !           800: 
        !           801:  non_reread:
        !           802: 
        !           803:   /* Cancel alarm if it was set and has not already gone off. */
        !           804:   if (alarmtime > 0) alarm (0);
        !           805: 
        !           806:   minibuf_message = 0;
        !           807: 
        !           808:   if (c < 0) return -1;
        !           809: 
        !           810:   c &= MetaFlag ? 0377 : 0177;
        !           811: 
        !           812:   if (XTYPE (Vkeyboard_translate_table) == Lisp_String
        !           813:       && XSTRING (Vkeyboard_translate_table)->size > c)
        !           814:     c = XSTRING (Vkeyboard_translate_table)->data[c];
        !           815: 
        !           816:   total_keys++;
        !           817:   recent_keys[recent_keys_index] = c;
        !           818:   recent_keys_index = (recent_keys_index + 1) % sizeof recent_keys;
        !           819: 
        !           820:   if (dribble)
        !           821:     {
        !           822:       putc (c, dribble);
        !           823:       fflush (dribble);
        !           824:     }
        !           825: 
        !           826:   store_kbd_macro_char (c);
        !           827: 
        !           828:  from_macro:
        !           829:   if (NextK < sizeof KeyBuf)
        !           830:     KeyBuf[NextK++] = c;
        !           831: 
        !           832:   /* If already echoing, echo right away. */
        !           833:   if (Echo1 /*|| cursor_in_echo_area*/ )
        !           834:     EchoThem (0);
        !           835: 
        !           836:  reread:
        !           837:   /* If the first character of a command is being reread,
        !           838:      store it in case a pause follows and it must be echoed later.
        !           839:      This has no effect on a non-reread character
        !           840:      since NextK is not zero here for them.  */
        !           841:   if (NextK == 0)
        !           842:     KeyBuf[NextK++] = c;
        !           843: 
        !           844:   last_input_char = c;
        !           845: 
        !           846:   num_input_chars++;
        !           847: 
        !           848:   /* Process the help character specially if enabled */
        !           849:   if (c == help_char && !NULL (Vhelp_form))
        !           850:     {
        !           851:       count = specpdl_ptr - specpdl;
        !           852: 
        !           853:       record_unwind_protect (Fset_window_configuration,
        !           854:                             Fcurrent_window_configuration ());
        !           855: 
        !           856:       tem = Feval (Vhelp_form);
        !           857:       if (XTYPE (tem) == Lisp_String)
        !           858:        internal_with_output_to_temp_buffer ("*Help*", print_help, tem);
        !           859: 
        !           860:       NextK = 0;
        !           861:       c = get_char (0);
        !           862:       /* Remove the help from the screen */
        !           863:       unbind_to (count);
        !           864:       DoDsp (0);
        !           865:       if (c == 040)
        !           866:        {
        !           867:          NextK = 0;
        !           868:          c = get_char (0);
        !           869:        }
        !           870:     }
        !           871: 
        !           872:   return c;
        !           873: }
        !           874: 
        !           875: Lisp_Object
        !           876: print_help (object)
        !           877:      Lisp_Object object;
        !           878: {
        !           879:   Fprinc (object, Qnil);
        !           880:   return Qnil;
        !           881: }
        !           882: 
        !           883: /* Low level keyboard input.
        !           884:  Read characters into kbd_buffer
        !           885:  from which they are obtained by kbd_buffer_get_char.  */
        !           886: 
        !           887: /* Set this for debugging, to have a way to get out */
        !           888: int stop_character;
        !           889: 
        !           890: /* Store a character obtained at interrupt level into kbd_buffer, fifo */
        !           891: kbd_buffer_store_char (c)
        !           892:      register int c;
        !           893: {
        !           894:   c &= 0377;
        !           895: 
        !           896:   if (c == Ctl ('g')
        !           897:       || ((c == (0200 | Ctl ('g'))) && !MetaFlag))
        !           898:     {
        !           899:       interrupt_signal ();
        !           900:       return;
        !           901:     }
        !           902: 
        !           903:   if (c && c == stop_character)
        !           904:     {
        !           905:       sys_suspend ();
        !           906:       return;
        !           907:     }
        !           908: 
        !           909:   if (kbd_ptr != kbd_buffer)
        !           910:     {
        !           911:       bcopy (kbd_ptr, kbd_buffer, kbd_count);
        !           912:       kbd_ptr = kbd_buffer;
        !           913:     }
        !           914: 
        !           915:   if (kbd_count < sizeof kbd_buffer)
        !           916:     {
        !           917:       kbd_buffer[kbd_count++] = c;
        !           918:     }
        !           919: }
        !           920: 
        !           921: kbd_buffer_get_char ()
        !           922: {
        !           923:   register int c;
        !           924: 
        !           925:   if (noninteractive)
        !           926:     {
        !           927:       c = getchar ();
        !           928:       return c;
        !           929:     }
        !           930: 
        !           931:   /* Either ordinary input buffer or C-g buffered means we can return.  */
        !           932:   while (!kbd_count)
        !           933:     {
        !           934:       if (!NULL (Vquit_flag))
        !           935:        quit_throw_to_get_char ();
        !           936: 
        !           937:       /* One way or another, wait until input is available; then, if
        !           938:         interrupt handlers have not read it, read it now.  */
        !           939: 
        !           940: #ifdef VMS
        !           941:       set_waiting_for_input (0);
        !           942:       wait_for_kbd_input ();
        !           943:       clear_waiting_for_input (0);
        !           944: #else
        !           945: /* Note SIGIO has been undef'd if FIONREAD is missing.  */
        !           946: #ifdef SIGIO
        !           947:       gobble_input ();
        !           948: #endif /* SIGIO */
        !           949:       if (!kbd_count)
        !           950:        {
        !           951: #ifdef subprocesses
        !           952:          wait_reading_process_input (0, -1, 1);
        !           953: #else
        !           954: /* Note SIGIO has been undef'd if FIONREAD is missing.  */
        !           955: #ifdef SIGIO
        !           956:          if (interrupt_input)
        !           957:            {
        !           958:              sigblockx (SIGIO);
        !           959:              set_waiting_for_input (0);
        !           960:              while (!kbd_count)
        !           961:                sigpausex (SIGIO);
        !           962:              clear_waiting_for_input ();
        !           963:              sigunblockx (SIGIO);
        !           964:            }
        !           965: #else
        !           966:          interrupt_input = 0;
        !           967: #endif /* not SIGIO */
        !           968: #endif /* subprocesses */
        !           969: 
        !           970:          if (!interrupt_input && !kbd_count)
        !           971:            {
        !           972:              read_avail_input (0);
        !           973:            }
        !           974:        }
        !           975: #endif /* not VMS */
        !           976:     }
        !           977: 
        !           978:   input_pending = --kbd_count > 0;
        !           979:   c = *kbd_ptr;                        /* *kbd_ptr++ would have a timing error. */
        !           980:   kbd_ptr++;                   /* See kbd_buffer_store_char. */
        !           981:   return (c & (MetaFlag ? 0377 : 0177)); /* Clean up if sign was extended. */
        !           982: }
        !           983: 
        !           984: /* Force an attempt to read input regardless of what FIONREAD says.  */
        !           985: 
        !           986: force_input_read ()
        !           987: {
        !           988:   force_input = 1;
        !           989:   detect_input_pending ();
        !           990:   force_input = 0;
        !           991: }
        !           992: 
        !           993: /* Store into *addr the number of terminal input chars available.
        !           994:    Equivalent to ioctl (0, FIONREAD, addr) but works
        !           995:    even if FIONREAD does not exist.  */
        !           996: 
        !           997: static void
        !           998: get_input_pending (addr)
        !           999:      int *addr;
        !          1000: {
        !          1001: #ifdef VMS
        !          1002:   /* On VMS, we always have something in the buffer
        !          1003:      if any input is available.  */
        !          1004:   /*** It might be simpler to make interrupt_input 1 on VMS ***/
        !          1005:   *addr = kbd_count | !NULL (Vquit_flag);
        !          1006: #else
        !          1007:   /* First of all, have we already counted some input?  */
        !          1008:   *addr = kbd_count | !NULL (Vquit_flag);
        !          1009:   /* If input is being read as it arrives, and we have none, there is none.  */
        !          1010:   if (*addr > 0 || (interrupt_input && ! interrupts_deferred && ! force_input))
        !          1011:     return;
        !          1012: #ifdef FIONREAD
        !          1013:   if (! force_input)
        !          1014:     {
        !          1015:       /* If we can count the input without reading it, do so.  */
        !          1016:       if (ioctl (0, FIONREAD, addr) < 0)
        !          1017:        *addr = 0;
        !          1018:       if (*addr == 0 || read_socket_hook == 0)
        !          1019:        return;
        !          1020:       /* If the input consists of window-events, not all of them
        !          1021:         are necessarily kbd chars.  So process all the input
        !          1022:         and see how many kbd chars we got.  */
        !          1023:     }
        !          1024: #endif
        !          1025: #ifdef SIGIO
        !          1026:   {
        !          1027:     /* It seems there is a timing error such that a SIGIO can be handled here
        !          1028:        and cause kbd_count to become nonzero even though raising of SIGIO
        !          1029:        has already been turned off.  */
        !          1030:     int mask = sigblock (sigmask (SIGIO));
        !          1031:     if (kbd_count == 0)
        !          1032:       read_avail_input (*addr);
        !          1033:     sigsetmask (mask);
        !          1034:   }
        !          1035: #else
        !          1036:   /* If we can't count the input, read it (if any) and see what we got.  */
        !          1037:   read_avail_input (*addr);
        !          1038: #endif
        !          1039:   *addr = kbd_count;
        !          1040: #endif
        !          1041: }
        !          1042: 
        !          1043: /* Read any terminal input already buffered up by the system
        !          1044:    into the kbd_buffer, assuming the buffer is currently empty.
        !          1045:    Never waits.  We assume that kbd_buffer is empty before you call.
        !          1046: 
        !          1047:    If NREAD is nonzero, assume it contains # chars of raw data waiting.
        !          1048:    If it is zero, we determine that datum.
        !          1049: 
        !          1050:    Input gets into the kbd_buffer either through this function
        !          1051:    (at main program level) or at interrupt level if input
        !          1052:    is interrupt-driven.  */
        !          1053: 
        !          1054: static void
        !          1055: read_avail_input (nread)
        !          1056:      int nread;
        !          1057: {
        !          1058:   /* This function is not used on VMS.  */
        !          1059: #ifndef VMS
        !          1060: #ifdef FIONREAD
        !          1061:   char buf[256 * BUFFER_SIZE_FACTOR];
        !          1062:   register char *p;
        !          1063:   register int i;
        !          1064: 
        !          1065:   if (kbd_count)
        !          1066:     abort ();
        !          1067: 
        !          1068:   if (! force_input)
        !          1069:     {
        !          1070:       if (nread == 0)
        !          1071:        get_input_pending (&nread);
        !          1072:       if (nread == 0)
        !          1073:        return;
        !          1074:     }
        !          1075:   if (nread > sizeof buf)
        !          1076:     nread = sizeof buf;
        !          1077: 
        !          1078:   /* Read what is waiting.  */
        !          1079:   if (read_socket_hook)
        !          1080:     nread = (*read_socket_hook) (0, buf, nread);
        !          1081:   else
        !          1082:     nread = read (0, buf, nread);
        !          1083: 
        !          1084:   /* Scan the chars for C-g and store them in kbd_buffer.  */
        !          1085:   kbd_ptr = kbd_buffer;
        !          1086:   for (i = 0; i < nread; i++)
        !          1087:     {
        !          1088:       kbd_buffer_store_char (buf[i]);
        !          1089:       /* Don't look at input that follows a C-g too closely.
        !          1090:         This reduces lossage due to autorepeat on C-g.  */
        !          1091:       if (buf[i] == Ctl ('G'))
        !          1092:        break;
        !          1093:     }
        !          1094: 
        !          1095: #else /* no FIONREAD */
        !          1096: #ifdef USG
        !          1097:   if (kbd_count)
        !          1098:     abort ();
        !          1099: 
        !          1100:   fcntl (fileno (stdin), F_SETFL, O_NDELAY);
        !          1101:   kbd_ptr = kbd_buffer;
        !          1102:   if (read_socket_hook)
        !          1103:     {
        !          1104:       kbd_count = (*read_socket_hook) (0, kbd_buffer, sizeof kbd_buffer);
        !          1105:     }
        !          1106:   else
        !          1107:     {
        !          1108:       kbd_count = read (fileno (stdin), kbd_buffer, sizeof kbd_buffer);
        !          1109:     }
        !          1110: #ifdef EBADSLT
        !          1111:   if (kbd_count == -1 && (errno == EAGAIN || errno == EBADSLT))
        !          1112: #else
        !          1113:   if (kbd_count == -1 && errno == EAGAIN)
        !          1114: #endif
        !          1115:     kbd_count = 0;
        !          1116:   fcntl (fileno (stdin), F_SETFL, 0);
        !          1117: #else /* not USG */
        !          1118:   you lose
        !          1119: #endif /* not USG */
        !          1120: #endif /* no FIONREAD */
        !          1121: #endif /* not VMS */
        !          1122: }
        !          1123: 
        !          1124: #ifdef SIGIO   /* for entire page */
        !          1125: /* Note SIGIO has been undef'd if FIONREAD is missing.  */
        !          1126: 
        !          1127: /* If using interrupt input and some input chars snuck into the
        !          1128:    buffer before we enabled interrupts, fake an interrupt for them.  */
        !          1129: 
        !          1130: gobble_input ()
        !          1131: {
        !          1132:   int nread;
        !          1133:   if (interrupt_input)
        !          1134:     {
        !          1135:       if (ioctl (0, FIONREAD, &nread) < 0)
        !          1136:        nread = 0;
        !          1137:       if (nread)
        !          1138:        {
        !          1139:          sigholdx (SIGIO);
        !          1140:          input_available_signal (SIGIO);
        !          1141:          sigfree ();
        !          1142:        }
        !          1143:     }
        !          1144: }
        !          1145: 
        !          1146: input_available_signal (signo)
        !          1147:      int signo;
        !          1148: {
        !          1149:   unsigned char buf[256 * BUFFER_SIZE_FACTOR];
        !          1150:   int nread;
        !          1151:   register int i;
        !          1152:   /* Must preserve main program's value of errno.  */
        !          1153:   int old_errno = errno;
        !          1154: #ifdef BSD4_1
        !          1155:   extern int select_alarmed;
        !          1156: #endif
        !          1157: 
        !          1158: #ifdef USG
        !          1159:   /* USG systems forget handlers when they are used;
        !          1160:      must reestablish each time */
        !          1161:   signal (signo, input_available_signal);
        !          1162: #endif /* USG */
        !          1163: 
        !          1164: #ifdef BSD4_1
        !          1165:   sigisheld (SIGIO);
        !          1166: #endif
        !          1167: 
        !          1168:   if (input_available_clear_word)
        !          1169:     *input_available_clear_word = 0;
        !          1170: 
        !          1171:   while (1)
        !          1172:     {
        !          1173:       if (ioctl (0, FIONREAD, &nread) < 0)
        !          1174:        nread = 0;
        !          1175:       if (nread <= 0)
        !          1176:        break;
        !          1177: #ifdef BSD4_1
        !          1178:       select_alarmed = 1;  /* Force the select emulator back to life */
        !          1179: #endif
        !          1180:       if (read_socket_hook)
        !          1181:        {
        !          1182:          nread = (*read_socket_hook) (0, buf, sizeof buf);
        !          1183:          if (!nread)
        !          1184:            continue;
        !          1185:        }
        !          1186:       else
        !          1187:        {
        !          1188:          if (nread > sizeof buf)
        !          1189:            nread = sizeof buf;
        !          1190:          nread = read (0, buf, nread);
        !          1191:        }
        !          1192: 
        !          1193:       for (i = 0; i < nread; i++)
        !          1194:        {
        !          1195:          kbd_buffer_store_char (buf[i]);
        !          1196:          /* Don't look at input that follows a C-g too closely.
        !          1197:             This reduces lossage due to autorepeat on C-g.  */
        !          1198:          if (buf[i] == Ctl('G'))
        !          1199:            break;
        !          1200:        }
        !          1201:     }
        !          1202: #ifdef BSD4_1
        !          1203:   sigfree ();
        !          1204: #endif
        !          1205:   errno = old_errno;
        !          1206: }
        !          1207: #endif /* SIGIO */
        !          1208: 
        !          1209: #if 0
        !          1210: /* This is turned off because it didn't produce much speedup.  */
        !          1211: 
        !          1212: /* Read a single-char key sequence.  Do not redisplay.
        !          1213:    Return 1 if successful, or 0 if what follows is not
        !          1214:    a single-char key.  (In that case, a char has been unread.)
        !          1215:    This is used instead of read_key_sequence as an optimization
        !          1216:    just after a direct-updating command is done, since at such
        !          1217:    times we know that no redisplay is required.  */
        !          1218: 
        !          1219: int
        !          1220: fast_read_one_key (keybuf)
        !          1221:      char *keybuf;
        !          1222: {
        !          1223:   register Lisp_Object map;
        !          1224:   register int c;
        !          1225:   register Lisp_Object tem;
        !          1226: 
        !          1227:   keys_prompt = 0;
        !          1228:   /* Read a character, and do not redisplay.  */
        !          1229:   c = get_char (-1);
        !          1230:   Vquit_flag = Qnil;
        !          1231: 
        !          1232:   /* Assume until further notice that we are unlucky
        !          1233:      and will return zero, so this char will be
        !          1234:      reread by read_key_sequence.  */
        !          1235: 
        !          1236:   unread_command_char = c;
        !          1237: 
        !          1238:   if (c < 0 || c >= 0200)
        !          1239:     return 0;
        !          1240: 
        !          1241:   map = bf_cur->keymap;
        !          1242:   if (!EQ (map, Qnil))
        !          1243:     {
        !          1244:       tem = get_keyelt (access_keymap (map, c));
        !          1245:       if (!EQ (tem, Qnil))
        !          1246:        return 0;
        !          1247:     }
        !          1248: 
        !          1249:   XSET (map, Lisp_Vector, CurrentGlobalMap);
        !          1250:   tem = !NULL (map)
        !          1251:     ? get_keyelt (access_keymap (map, c))
        !          1252:       : Qnil;
        !          1253: 
        !          1254:   read_key_sequence_cmd = tem;
        !          1255: 
        !          1256:   /* trace symbols to their function definitions */
        !          1257: 
        !          1258:   while (XTYPE (tem) == Lisp_Symbol && !NULL (tem)
        !          1259:         && !EQ (tem, Qunbound))
        !          1260:     tem = XSYMBOL (tem)->function;
        !          1261: 
        !          1262:   /* Is the definition a prefix character?  */
        !          1263: 
        !          1264:   if (XTYPE (tem) == Lisp_Vector ||
        !          1265:       (CONSP (tem) && EQ (XCONS (tem)->car, Qkeymap)))
        !          1266:     return 0;
        !          1267: 
        !          1268:   unread_command_char = -1;
        !          1269:   keybuf[0] = c;
        !          1270:   return 1;
        !          1271: }
        !          1272: 
        !          1273: #endif /* 0 */
        !          1274: 
        !          1275: /* Read a sequence of keys that ends with a non prefix character,
        !          1276:  and store them in KEYBUF, a buffer of size BUFSIZE.
        !          1277:  Prompt with PROMPT.  Echo starting immediately unless `prompt' is 0.
        !          1278:  Return the length of the key sequence stored.
        !          1279:  NODISPLAY nonzero means don't do redisplay before the first character
        !          1280:  (just for speedup).  */
        !          1281: 
        !          1282: int
        !          1283: read_key_sequence (keybuf, bufsize, prompt, nodisplay)
        !          1284:      char *keybuf;
        !          1285:      int bufsize;
        !          1286:      unsigned char *prompt;
        !          1287:      int nodisplay;
        !          1288: {
        !          1289:   register int i;
        !          1290:   Lisp_Object nextlocal, nextglobal;
        !          1291:   register int c, nextc;
        !          1292:   Lisp_Object local, global;
        !          1293: 
        !          1294:   keys_prompt = prompt;
        !          1295: 
        !          1296:   if (prompt)
        !          1297:     NextK = 0;
        !          1298:   if ((prompt || cursor_in_echo_area) && INTERACTIVE)
        !          1299:     EchoThem (1);
        !          1300: 
        !          1301:   nextc = get_char (nodisplay ? -1 : !prompt);
        !          1302:   nextlocal = bf_cur->keymap;
        !          1303:   XSET (nextglobal, Lisp_Vector, CurrentGlobalMap);
        !          1304: 
        !          1305:   i = 0;
        !          1306:   while (!NULL (nextlocal) || !NULL (nextglobal))
        !          1307:     {
        !          1308:       if (i == bufsize)
        !          1309:        error ("key sequence too long");
        !          1310: 
        !          1311:       if (nextc >= 0)
        !          1312:        {
        !          1313:          c = nextc;
        !          1314:          nextc = -1;
        !          1315:        }
        !          1316:       else
        !          1317:        c = get_char (!prompt);
        !          1318:       Vquit_flag = Qnil;
        !          1319:       nodisplay = 0;
        !          1320: 
        !          1321:       if (c < 0)
        !          1322:        return 0;
        !          1323:       if (c >= 0200)
        !          1324:        {
        !          1325:          nextc = c & 0177;
        !          1326:          c = meta_prefix_char;
        !          1327:        }
        !          1328: 
        !          1329:       keybuf[i] = c;
        !          1330: 
        !          1331:       global = !NULL (nextglobal)
        !          1332:        ? get_keyelt (access_keymap (nextglobal, c))
        !          1333:          : Qnil;
        !          1334: 
        !          1335:       local = !NULL (nextlocal)
        !          1336:        ? get_keyelt (access_keymap (nextlocal, c))
        !          1337:          : Qnil;
        !          1338: 
        !          1339:       /* If C is not defined in either keymap
        !          1340:         and it is an uppercase letter, try corresponding lowercase.  */
        !          1341: 
        !          1342:       if (NULL (global) && NULL (local) && UPPERCASEP (c))
        !          1343:        {
        !          1344:          global = !NULL (nextglobal)
        !          1345:            ? get_keyelt (access_keymap (nextglobal, DOWNCASE (c)))
        !          1346:              : Qnil;
        !          1347: 
        !          1348:          local = !NULL (nextlocal)
        !          1349:            ? get_keyelt (access_keymap (nextlocal, DOWNCASE (c)))
        !          1350:              : Qnil;
        !          1351: 
        !          1352:          /* If that has worked better that the original char,
        !          1353:             downcase it permanently.  */
        !          1354: 
        !          1355:          if (!NULL (global) || !NULL (local))
        !          1356:            {
        !          1357:              keybuf[i] = c = DOWNCASE (c);
        !          1358:            }
        !          1359:        }
        !          1360: 
        !          1361:       i++;
        !          1362: 
        !          1363:       nextlocal = Qnil;
        !          1364:       nextglobal = Qnil;
        !          1365: 
        !          1366:       read_key_sequence_cmd = !NULL (local) ? local : global;
        !          1367: 
        !          1368:       /* trace symbols to their function definitions */
        !          1369: 
        !          1370:       while (XTYPE (global) == Lisp_Symbol && !NULL (global)
        !          1371:             && !EQ (global, Qunbound))
        !          1372:        global = XSYMBOL (global)->function;
        !          1373:       while (XTYPE (local) == Lisp_Symbol && !NULL (local)
        !          1374:             && !EQ (local, Qunbound))
        !          1375:        local = XSYMBOL (local)->function;
        !          1376: 
        !          1377:       /* Are the definitions prefix characters? */
        !          1378: 
        !          1379:       if (XTYPE (local) == Lisp_Vector ||
        !          1380:          (CONSP (local) && EQ (XCONS (local)->car, Qkeymap))
        !          1381:          ||
        !          1382:          /* If nextc is set, we are processing a prefix char
        !          1383:             that represents a meta-bit.
        !          1384:             Let a global prefix definition override a local non-prefix.
        !          1385:             This is for minibuffers that redefine Escape for completion.
        !          1386:             A real Escape gets completion, but Meta bits get ESC-prefix.  */
        !          1387:          ((NULL (local) || nextc >= 0)
        !          1388:           && (XTYPE (global) == Lisp_Vector ||
        !          1389:               (CONSP (global) && EQ (XCONS (global)->car, Qkeymap)))))
        !          1390:        {
        !          1391:          if (XTYPE (local) == Lisp_Vector ||
        !          1392:              (CONSP (local) && EQ (XCONS (local)->car, Qkeymap)))
        !          1393:            nextlocal = local;
        !          1394:          else
        !          1395:            nextlocal = Qnil;
        !          1396: 
        !          1397:          if (XTYPE (global) == Lisp_Vector ||
        !          1398:              (CONSP (global) && EQ (XCONS (global)->car, Qkeymap)))
        !          1399:            nextglobal = global;
        !          1400:          else
        !          1401:            nextglobal = Qnil;
        !          1402:        }
        !          1403:     }
        !          1404: 
        !          1405:   keys_prompt = 0;
        !          1406:   return i;
        !          1407: }
        !          1408: 
        !          1409: DEFUN ("read-key-sequence", Fread_key_sequence, Sread_key_sequence, 1, 1, 0,
        !          1410:   "Read a sequence of keystrokes and return as a string.\n\
        !          1411: The sequence is sufficient to specify a non-prefix command\n\
        !          1412: starting from the current local and global keymaps.\n\
        !          1413: A C-g typed while in this function is treated like\n\
        !          1414: any other character, and quit-flag is not set.\n\
        !          1415: One arg, PROMPT, a prompt string or  nil, meaning do not prompt specially.")
        !          1416:   (prompt)
        !          1417:      Lisp_Object prompt;
        !          1418: {
        !          1419:   char keybuf[30];
        !          1420:   register int i;
        !          1421: 
        !          1422:   if (!NULL (prompt))
        !          1423:     CHECK_STRING (prompt, 0);
        !          1424:   QUIT;
        !          1425:   i = read_key_sequence (keybuf, sizeof keybuf,
        !          1426:                         (NULL (prompt)) ? 0 : XSTRING (prompt)->data,
        !          1427:                         0);
        !          1428:   return make_string (keybuf, i);
        !          1429: }
        !          1430: 
        !          1431: DEFUN ("command-execute", Fcommand_execute, Scommand_execute, 1, 2, 0,
        !          1432:  "Execute CMD as an editor command.\n\
        !          1433: CMD must be a symbol that satisfies the `commandp' predicate.\n\
        !          1434: Optional second arg RECORD-FLAG non-nil\n\
        !          1435: means unconditionally put this command in the command-history.\n\
        !          1436: Otherwise, this is done only if an arg is read using the minibuffer.")
        !          1437:      (cmd, record)
        !          1438:      Lisp_Object cmd, record;
        !          1439: {
        !          1440:   register Lisp_Object final;
        !          1441:   register Lisp_Object tem;
        !          1442:   Lisp_Object prefixarg;
        !          1443:   struct backtrace backtrace;
        !          1444:   extern int debug_on_next_call;
        !          1445: 
        !          1446:   prefixarg = Vprefix_arg, Vprefix_arg = Qnil;
        !          1447:   Vcurrent_prefix_arg = prefixarg;
        !          1448:   debug_on_next_call = 0;
        !          1449: 
        !          1450:   if (XTYPE (cmd) == Lisp_Symbol)
        !          1451:     {
        !          1452:       tem = Fget (cmd, Qdisabled);
        !          1453:       if (!NULL (tem))
        !          1454:        return call0 (Vdisabled_command_hook);
        !          1455:     }
        !          1456: 
        !          1457:   while (1)
        !          1458:     {
        !          1459:       final = cmd;
        !          1460:       while (XTYPE (final) == Lisp_Symbol)
        !          1461:        {
        !          1462:          if (EQ (Qunbound, XSYMBOL (final)->function))
        !          1463:            Fsymbol_function (final);    /* Get an error! */
        !          1464:          final = XSYMBOL (final)->function;
        !          1465:        }
        !          1466: 
        !          1467:       if (CONSP (final) && (tem = Fcar (final), EQ (tem, Qautoload)))
        !          1468:        do_autoload (final, cmd);
        !          1469:       else
        !          1470:        break;
        !          1471:     }
        !          1472: 
        !          1473:   if (CONSP (final) || XTYPE (final) == Lisp_Subr)
        !          1474:     {
        !          1475:       backtrace.next = backtrace_list;
        !          1476:       backtrace_list = &backtrace;
        !          1477:       backtrace.function = &Qcall_interactively;
        !          1478:       backtrace.args = &cmd;
        !          1479:       backtrace.nargs = 1;
        !          1480:       backtrace.evalargs = 0;
        !          1481: 
        !          1482:       tem = Fcall_interactively (cmd, record);
        !          1483: 
        !          1484:       backtrace_list = backtrace.next;
        !          1485:       return tem;
        !          1486:     }
        !          1487:   if (XTYPE (final) == Lisp_String)
        !          1488:     {
        !          1489:       return Fexecute_kbd_macro (final, prefixarg);
        !          1490:     }
        !          1491:   return Qnil;
        !          1492: }
        !          1493: 
        !          1494: DEFUN ("execute-extended-command", Fexecute_extended_command, Sexecute_extended_command,
        !          1495:   1, 1, "P",
        !          1496:   "Read function name, then read its arguments and call it.")
        !          1497:   (prefixarg)
        !          1498:      Lisp_Object prefixarg;
        !          1499: {
        !          1500:   Lisp_Object function;
        !          1501:   char buf[40];
        !          1502:   char saved_keys[40];
        !          1503:   int saved_keys_len = min (NextK, sizeof (saved_keys));
        !          1504: 
        !          1505:   bcopy (KeyBuf, saved_keys, saved_keys_len);
        !          1506: 
        !          1507:   buf[0] = 0;
        !          1508: 
        !          1509:   if (EQ (prefixarg, Qminus))
        !          1510:     strcpy (buf, "- ");
        !          1511:   else if (CONSP (prefixarg) && XINT (XCONS (prefixarg)->car) == 4)
        !          1512:     strcpy (buf, "C-u ");
        !          1513:   else if (CONSP (prefixarg) && XTYPE (XCONS (prefixarg)->car) == Lisp_Int)
        !          1514:     sprintf (buf, "%d ", XINT (XCONS (prefixarg)->car));
        !          1515:   else if (XTYPE (prefixarg) == Lisp_Int)
        !          1516:     sprintf (buf, "%d ", XINT (prefixarg));
        !          1517: 
        !          1518:   /* This isn't strictly correct if execute-extended-command
        !          1519:      is bound to anything else */
        !          1520:   strcat (buf, "M-x ");
        !          1521: 
        !          1522:   function = Fcompleting_read (build_string (buf), Vobarray, Qcommandp, Qt, Qnil);
        !          1523: 
        !          1524:   saved_keys_len = min (saved_keys_len, sizeof (KeyBuf));
        !          1525:   bcopy (saved_keys, KeyBuf, saved_keys_len);
        !          1526:   if (saved_keys_len >= sizeof (KeyBuf))
        !          1527:     NextK = sizeof (KeyBuf);
        !          1528:   else
        !          1529:     {
        !          1530:       int l = XSTRING (function)->size;
        !          1531:       l = min (sizeof (KeyBuf) - saved_keys_len, l);
        !          1532:       bcopy (XSTRING (function)->data, KeyBuf + saved_keys_len, l);
        !          1533:       NextK = saved_keys_len + l;
        !          1534:     }
        !          1535: 
        !          1536:   function = Fintern (function, Vobarray);
        !          1537:   Vprefix_arg = prefixarg;
        !          1538:   this_command = function;
        !          1539: 
        !          1540:   return Fcommand_execute (function, Qt);
        !          1541: }
        !          1542: 
        !          1543: 
        !          1544: detect_input_pending ()
        !          1545: {
        !          1546:   if (!input_pending)
        !          1547:     get_input_pending (&input_pending);
        !          1548: 
        !          1549:   return input_pending;
        !          1550: }
        !          1551: 
        !          1552: DEFUN ("input-pending-p", Finput_pending_p, Sinput_pending_p, 0, 0, 0,
        !          1553:   "T if command input is currently available with no waiting.\n\
        !          1554: Actually, the value is NIL only if we can be sure that no input is available.")
        !          1555:   ()
        !          1556: {
        !          1557:   if (unread_command_char >= 0) return Qt;
        !          1558: 
        !          1559:   return detect_input_pending () ? Qt : Qnil;
        !          1560: }
        !          1561: 
        !          1562: DEFUN ("recent-keys", Frecent_keys, Srecent_keys, 0, 0, 0,
        !          1563:   "Return string of last 100 chars read from terminal.")
        !          1564:   ()
        !          1565: {
        !          1566:   Lisp_Object val;
        !          1567:   if (total_keys < sizeof recent_keys)
        !          1568:     return make_string (recent_keys, total_keys);
        !          1569: 
        !          1570:   val = make_string (recent_keys, sizeof recent_keys);
        !          1571:   bcopy (recent_keys + recent_keys_index,
        !          1572:         XSTRING (val)->data,
        !          1573:         sizeof recent_keys - recent_keys_index);
        !          1574:   bcopy (recent_keys,
        !          1575:         XSTRING (val)->data + sizeof recent_keys - recent_keys_index,
        !          1576:         recent_keys_index);
        !          1577:   return val;
        !          1578: }
        !          1579: 
        !          1580: DEFUN ("this-command-keys", Fthis_command_keys, Sthis_command_keys, 0, 0, 0,
        !          1581:   "Return string of the keystrokes that invoked this command.")
        !          1582:   ()
        !          1583: {
        !          1584:   return make_string (KeyBuf, NextK);
        !          1585: }
        !          1586: 
        !          1587: DEFSIMPLE ("recursion-depth", Frecursion_depth, Srecursion_depth,
        !          1588:           "Return the current depth in recursive edits.",
        !          1589:           Lisp_Int, XSETINT, RecurseDepth)
        !          1590: 
        !          1591: DEFUN ("open-dribble-file", Fopen_dribble_file, Sopen_dribble_file, 1, 1,
        !          1592:   "FOpen dribble file: ",
        !          1593:   "Start writing all keyboard characters to FILE.")
        !          1594:   (file)
        !          1595:      Lisp_Object file;
        !          1596: {
        !          1597:   file = Fexpand_file_name (file, Qnil);
        !          1598:   dribble = fopen (XSTRING (file)->data, "w");
        !          1599:   return Qnil;
        !          1600: }
        !          1601: 
        !          1602: DEFUN ("discard-input", Fdiscard_input, Sdiscard_input, 0, 0, 0,
        !          1603:   "Discard the contents of the terminal input buffer.\n\
        !          1604: Also flush any kbd macro definition in progress.")
        !          1605:   ()
        !          1606: {
        !          1607:   defining_kbd_macro = 0;
        !          1608:   RedoModes++;
        !          1609: 
        !          1610:   unread_command_char = -1;
        !          1611:   discard_tty_input ();
        !          1612: 
        !          1613:   kbd_count = 0;
        !          1614:   input_pending = 0;
        !          1615: 
        !          1616:   return Qnil;
        !          1617: }
        !          1618: 
        !          1619: DEFUN ("suspend-emacs", Fsuspend_emacs, Ssuspend_emacs, 0, 1, "",
        !          1620:   "Stop Emacs and return to superior process.  You can resume.\n\
        !          1621: If optional arg STUFFSTRING is non-nil, its characters are stuffed\n\
        !          1622: to be read as terminal input by Emacs's superior shell.\n\
        !          1623: Before suspending, if `suspend-hook' is bound and value is non-nil\n\
        !          1624: call the value as a function of no args.  Don't suspend if it returns non-nil.\n\
        !          1625: Otherwise, suspend normally and after resumption call\n\
        !          1626: `suspend-resume-hook' if that is bound and non-nil.")
        !          1627:   (stuffstring)
        !          1628:      Lisp_Object stuffstring;
        !          1629: {
        !          1630:   register Lisp_Object tem;
        !          1631:   int count = specpdl_ptr - specpdl;
        !          1632:   extern init_sys_modes ();
        !          1633: 
        !          1634:   if (!NULL (stuffstring))
        !          1635:     CHECK_STRING (stuffstring, 0);
        !          1636: 
        !          1637:   /* Call value of suspend-hook
        !          1638:      if it is bound and value is non-nil.  */
        !          1639:   tem = intern ("suspend-hook");
        !          1640:   tem = XSYMBOL (tem)->value;
        !          1641:   if (! EQ (tem, Qunbound) && ! EQ (tem, Qnil))
        !          1642:     {
        !          1643:       tem = call0 (tem);
        !          1644:       if (!EQ (tem, Qnil)) return Qnil;
        !          1645:     }
        !          1646: 
        !          1647:   reset_sys_modes ();
        !          1648:   /* sys_suspend can get an error if it tries to fork a subshell
        !          1649:      and the system resources aren't available for that.  */
        !          1650:   record_unwind_protect (init_sys_modes, 0);
        !          1651:   stuff_buffered_input (stuffstring);
        !          1652:   sys_suspend ();
        !          1653:   unbind_to (count);
        !          1654: 
        !          1655:   /* Call value of suspend-resume-hook
        !          1656:      if it is bound and value is non-nil.  */
        !          1657:   tem = intern ("suspend-resume-hook");
        !          1658:   tem = XSYMBOL (tem)->value;
        !          1659:   if (! EQ (tem, Qunbound) && ! EQ (tem, Qnil))
        !          1660:     call0 (tem);
        !          1661:   return Qnil;
        !          1662: }
        !          1663: 
        !          1664: /* If STUFFSTRING is a string, stuff its contents as pending terminal input.
        !          1665:    Then in any case stuff anthing Emacs has read ahead and not used.  */
        !          1666: 
        !          1667: stuff_buffered_input (stuffstring)
        !          1668:      Lisp_Object stuffstring;
        !          1669: {
        !          1670:   register unsigned char *p;
        !          1671: 
        !          1672: /* stuff_char works only in BSD, versions 4.2 and up.  */
        !          1673: #ifdef BSD
        !          1674: #ifndef BSD4_1
        !          1675:   if (XTYPE (stuffstring) == Lisp_String)
        !          1676:     {
        !          1677:       register int count;
        !          1678: 
        !          1679:       p = XSTRING (stuffstring)->data;
        !          1680:       count = XSTRING (stuffstring)->size;
        !          1681:       while (count-- > 0)
        !          1682:        stuff_char (*p++);
        !          1683:       stuff_char ('\n');
        !          1684:     }
        !          1685:   /* Anything we have read ahead, put back for the shell to read.  */
        !          1686:   while (kbd_count)
        !          1687:     {
        !          1688:       stuff_char (*kbd_ptr++);
        !          1689:       kbd_count--;
        !          1690:     }
        !          1691:   input_pending = 0;
        !          1692: #endif
        !          1693: #endif /* BSD and not BSD4_1 */
        !          1694: }
        !          1695: 
        !          1696: set_waiting_for_input (word_to_clear)
        !          1697:      long *word_to_clear;
        !          1698: {
        !          1699:   input_available_clear_word = word_to_clear;
        !          1700: 
        !          1701:   /* Tell interrupt_signal to throw back to get_char,  */
        !          1702:   waiting_for_input = 1;
        !          1703: 
        !          1704:   /* If interrupt_signal was called before and buffered a C-g,
        !          1705:      make it run again now, to avoid timing error.  */
        !          1706:   if (!NULL (Vquit_flag))
        !          1707:     quit_throw_to_get_char ();
        !          1708: 
        !          1709:   /* Tell alarm signal to echo right away */
        !          1710:   echo_now = 1;
        !          1711: 
        !          1712:   /* If alarm has gone off already, echo now.  */
        !          1713:   if (echo_flag)
        !          1714:     {
        !          1715:       EchoThem (1);
        !          1716:       echo_flag = 0;
        !          1717:     }
        !          1718: }
        !          1719: 
        !          1720: clear_waiting_for_input ()
        !          1721: {
        !          1722:   /* Tell interrupt_signal not to throw back to get_char,  */
        !          1723:   waiting_for_input = 0;
        !          1724:   echo_now = 0;
        !          1725:   input_available_clear_word = 0;
        !          1726: }
        !          1727: 
        !          1728: /* This routine is called at interrupt level in response to C-G.
        !          1729:  If interrupt_input, this is the handler for SIGINT.
        !          1730:  Otherwise, it is called from kbd_buffer_store_char,
        !          1731:  in handling SIGIO or SIGTINT.
        !          1732: 
        !          1733:  If `waiting_for_input' is non zero, then unless `echoing' is nonzero,
        !          1734:  immediately throw back to get_char.
        !          1735: 
        !          1736:  Otherwise it sets the Lisp variable  quit-flag  not-nil.
        !          1737:  This causes  eval  to throw, when it gets a chance.
        !          1738:  If  quit-flag  is already non-nil, it stops the job right away.  */
        !          1739: 
        !          1740: interrupt_signal ()
        !          1741: {
        !          1742:   char c;
        !          1743:   /* Must preserve main program's value of errno.  */
        !          1744:   int old_errno = errno;
        !          1745:   extern Lisp_Object Vwindow_system;
        !          1746: 
        !          1747: #ifdef USG
        !          1748:   /* USG systems forget handlers when they are used;
        !          1749:      must reestablish each time */
        !          1750:   signal (SIGINT, interrupt_signal);
        !          1751:   signal (SIGQUIT, interrupt_signal);
        !          1752: #endif /* USG */
        !          1753: 
        !          1754:   Echo1 = 0;
        !          1755: 
        !          1756:   if (!NULL (Vquit_flag) && NULL (Vwindow_system))
        !          1757:     {
        !          1758:       fflush (stdout);
        !          1759:       reset_sys_modes ();
        !          1760:       sigfree ();
        !          1761: #ifdef SIGTSTP                 /* Support possible in later USG versions */
        !          1762: /*
        !          1763:  * On systems which can suspend the current process and return to the original
        !          1764:  * shell, this command causes the user to end up back at the shell.
        !          1765:  * The "Auto-save" and "Abort" questions are not asked until
        !          1766:  * the user elects to return to emacs, at which point he can save the current
        !          1767:  * job and either dump core or continue.
        !          1768:  */
        !          1769:       sys_suspend ();
        !          1770: #else
        !          1771: #ifdef VMS
        !          1772:       if (sys_suspend () == -1)
        !          1773:        {
        !          1774:          printf ("Not running as a subprocess;\n");
        !          1775:          printf ("you can continue or abort.\n");
        !          1776:        }
        !          1777: #else /* not VMS */
        !          1778:       /* Perhaps should really fork an inferior shell?
        !          1779:         But that would not provide any way to get back
        !          1780:         to the original shell, ever.  */
        !          1781:       printf ("No support for stopping a process on this operating system;\n");
        !          1782:       printf ("you can continue or abort.\n");
        !          1783: #endif /* not VMS */
        !          1784: #endif /* not SIGTSTP */
        !          1785:       printf ("Auto-save? (y or n) ");
        !          1786:       fflush (stdout);
        !          1787:       if (((c = getchar ()) & ~040) == 'Y')
        !          1788:        Fdo_auto_save (Qnil);
        !          1789:       while (c != '\n') c = getchar ();
        !          1790: #ifdef VMS
        !          1791:       printf ("Abort (and enter debugger)? (y or n) ");
        !          1792: #else /* not VMS */
        !          1793:       printf ("Abort (and dump core)? (y or n) ");
        !          1794: #endif /* not VMS */
        !          1795:       fflush (stdout);
        !          1796:       if (((c = getchar ()) & ~040) == 'Y')
        !          1797:        abort ();
        !          1798:       while (c != '\n') c = getchar ();
        !          1799:       printf ("Continuing...\n");
        !          1800:       fflush (stdout);
        !          1801:       init_sys_modes ();
        !          1802:     }
        !          1803:   else
        !          1804:     {
        !          1805:       /* If executing a function that wants to be interrupted out of
        !          1806:             and the user has not deferred quitting by binding `inhibit-quit'
        !          1807:             then quit right away.  */
        !          1808:       if (immediate_quit && NULL (Vinhibit_quit))
        !          1809:        {
        !          1810:          immediate_quit = 0;
        !          1811:           sigfree ();
        !          1812:          Fsignal (Qquit, Qnil);
        !          1813:        }
        !          1814:       else
        !          1815:        /* Else request quit when it's safe */
        !          1816:        Vquit_flag = Qt;
        !          1817:     }
        !          1818: 
        !          1819:   if (waiting_for_input && !echoing)
        !          1820:     quit_throw_to_get_char ();
        !          1821: 
        !          1822:   errno = old_errno;
        !          1823: }
        !          1824: 
        !          1825: /* Handle a C-g by making get_char return C-g.  */
        !          1826: 
        !          1827: quit_throw_to_get_char ()
        !          1828: {
        !          1829:   quit_error_check ();
        !          1830:   sigfree ();
        !          1831:   /* Prevent another signal from doing this before we finish.  */
        !          1832:   waiting_for_input = 0;
        !          1833:   input_pending = 0;
        !          1834:   unread_command_char = -1;
        !          1835:   _longjmp (getcjmp, 1);
        !          1836: }
        !          1837: 
        !          1838: DEFUN ("set-input-mode", Fset_input_mode, Sset_input_mode, 2, 2, 0,
        !          1839:   "Set mode of reading keyboard input.\n\
        !          1840: First arg non-nil means use input interrupts; nil means use CBREAK mode.\n\
        !          1841: Second arg non-nil means use ^S/^Q flow control for output to terminal\n\
        !          1842:  (no effect except in CBREAK mode).")
        !          1843:   (interrupt, flow)
        !          1844:      Lisp_Object interrupt, flow;
        !          1845: {
        !          1846:   reset_sys_modes ();
        !          1847: #ifdef SIGIO
        !          1848: /* Note SIGIO has been undef'd if FIONREAD is missing.  */
        !          1849:   interrupt_input = !NULL (interrupt);
        !          1850: #else /* not SIGIO */
        !          1851:   interrupt_input = 0;
        !          1852: #endif /* not SIGIO */
        !          1853:   flow_control = !NULL (flow);
        !          1854:   init_sys_modes ();
        !          1855:   return Qnil;
        !          1856: }
        !          1857: 
        !          1858: init_keyboard ()
        !          1859: {
        !          1860:   RecurseDepth = -1;   /* Correct, before outermost invocation of editor loop */
        !          1861:   keys_prompt = 0;
        !          1862:   immediate_quit = 0;
        !          1863:   unread_command_char = -1;
        !          1864:   recent_keys_index = 0;
        !          1865:   total_keys = 0;
        !          1866:   kbd_count = 0;
        !          1867:   kbd_ptr = kbd_buffer;
        !          1868:   input_pending = 0;
        !          1869:   force_input = 0;
        !          1870:   if (!noninteractive)
        !          1871:     {
        !          1872:       signal (SIGINT, interrupt_signal);
        !          1873: #ifdef USG
        !          1874:       /* On USG systems, C-g is set up for both SIGINT and SIGQUIT
        !          1875:         and we can't tell which one it will give us.  */
        !          1876:       signal (SIGQUIT, interrupt_signal);
        !          1877: #endif /* USG */
        !          1878: /* Note SIGIO has been undef'd if FIONREAD is missing.  */
        !          1879: #ifdef SIGIO
        !          1880:       signal (SIGIO, input_available_signal);
        !          1881: #endif SIGIO
        !          1882:     }
        !          1883: 
        !          1884: /* Use interrupt input by default, if it works and noninterrupt input
        !          1885:    has deficiencies.  */
        !          1886: 
        !          1887: #ifdef INTERRUPT_INPUT
        !          1888:   interrupt_input = 1;
        !          1889: #else
        !          1890:   interrupt_input = 0;
        !          1891: #endif
        !          1892: 
        !          1893:   sigfree ();
        !          1894:   dribble = 0;
        !          1895: 
        !          1896:   if (keyboard_init_hook)
        !          1897:     (*keyboard_init_hook) ();
        !          1898: }
        !          1899: 
        !          1900: syms_of_keyboard ()
        !          1901: {
        !          1902:   Qself_insert_command = intern ("self-insert-command");
        !          1903:   staticpro (&Qself_insert_command);
        !          1904: 
        !          1905:   Qforward_char = intern ("forward-char");
        !          1906:   staticpro (&Qforward_char);
        !          1907: 
        !          1908:   Qbackward_char = intern ("backward-char");
        !          1909:   staticpro (&Qbackward_char);
        !          1910: 
        !          1911:   Qtop_level = intern ("top-level");
        !          1912:   staticpro (&Qtop_level);
        !          1913: 
        !          1914:   Qdisabled = intern ("disabled");
        !          1915:   staticpro (&Qdisabled);
        !          1916: 
        !          1917:   defsubr (&Sread_key_sequence);
        !          1918:   defsubr (&Srecursive_edit);
        !          1919:   defsubr (&Sinput_pending_p);
        !          1920:   defsubr (&Scommand_execute);
        !          1921:   defsubr (&Srecent_keys);
        !          1922:   defsubr (&Sthis_command_keys);
        !          1923:   defsubr (&Ssuspend_emacs);
        !          1924:   defsubr (&Sabort_recursive_edit);
        !          1925:   defsubr (&Sexit_recursive_edit);
        !          1926:   defsubr (&Srecursion_depth);
        !          1927:   defsubr (&Stop_level);
        !          1928:   defsubr (&Sdiscard_input);
        !          1929:   defsubr (&Sopen_dribble_file);
        !          1930:   defsubr (&Sset_input_mode);
        !          1931:   defsubr (&Sexecute_extended_command);
        !          1932: 
        !          1933:   DEFVAR_LISP ("disabled-command-hook", &Vdisabled_command_hook,
        !          1934:     "Value is called instead of any command that is disabled\n\
        !          1935: \(has a non-nil  disabled  property).");
        !          1936: 
        !          1937:   DEFVAR_BOOL ("meta-flag", &MetaFlag,
        !          1938:     "*Non-nil means treat 0200 bit in terminal input as Meta bit.");
        !          1939: 
        !          1940:   DEFVAR_INT ("last-command-char", &last_command_char,
        !          1941:     "Last terminal input character that was part of a command, as an integer.");
        !          1942: 
        !          1943:   DEFVAR_INT ("last-input-char", &last_input_char,
        !          1944:     "Last terminal input character, as an integer.");
        !          1945: 
        !          1946:   DEFVAR_INT ("unread-command-char", &unread_command_char,
        !          1947:     "Character to be read as next input from command input stream, or -1 if none.");
        !          1948: 
        !          1949:   DEFVAR_INT ("meta-prefix-char", &meta_prefix_char,
        !          1950:     "Meta-prefix character code.  Meta-foo as command input\n\
        !          1951: turns into this character followed by foo.");
        !          1952:   meta_prefix_char = 033;
        !          1953: 
        !          1954:   DEFVAR_LISP ("last-command", &last_command,
        !          1955:     "The last command executed.  Normally a symbol with a function definition,\n\
        !          1956: but can be whatever was found in the keymap, or whatever the variable\n\
        !          1957: `this-command' was set to by that command.");
        !          1958:   last_command = Qnil;
        !          1959: 
        !          1960:   DEFVAR_LISP ("this-command", &this_command,
        !          1961:     "The command now being executed.\n\
        !          1962: The command can set this variable; whatever is put here\n\
        !          1963: will be in  last-command  during the following command.");
        !          1964:   this_command = Qnil;
        !          1965: 
        !          1966:   DEFVAR_INT ("auto-save-interval", &auto_save_interval,
        !          1967:     "*Number of keyboard input characters between auto-saves.\n\
        !          1968: Zero means disable autosaving.");
        !          1969:   auto_save_interval = 300;
        !          1970: 
        !          1971:   DEFVAR_INT ("echo-keystrokes", &echo_keystrokes,
        !          1972:     "*Nonzero means echo unfinished commands after this many seconds of pause.");
        !          1973:   echo_keystrokes = 1;
        !          1974: 
        !          1975:   DEFVAR_INT ("help-char", &help_char,
        !          1976:     "Character to recognize as meaning Help.\n\
        !          1977: When it is read, do (eval help-form), and display result if it's a string.\n\
        !          1978: If help-form's value is nil, this char can be read normally.");
        !          1979:   help_char = Ctl ('H');
        !          1980: 
        !          1981:   DEFVAR_LISP ("help-form", &Vhelp_form,
        !          1982:     "Form to execute when character help-char is read.\n\
        !          1983: If the form returns a string, that string is displayed.\n\
        !          1984: If help-form is nil, the help char is not recognized.");
        !          1985:   Vhelp_form = Qnil;
        !          1986:   
        !          1987:   DEFVAR_LISP ("top-level", &Vtop_level,
        !          1988:     "Form to evaluate when Emacs starts up.\n\
        !          1989: Useful to set before you dump a modified Emacs.");
        !          1990:   Vtop_level = Qnil;
        !          1991: 
        !          1992:   DEFVAR_LISP ("keyboard-translate-table", &Vkeyboard_translate_table,
        !          1993:     "String used as translate table for keyboard input, or nil.\n\
        !          1994: Each character is looked up in this string and the contents used instead.\n\
        !          1995: If string is of length N, character codes N and up are untranslated."); 
        !          1996:   Vkeyboard_translate_table = Qnil;
        !          1997: }
        !          1998: 
        !          1999: keys_of_keyboard ()
        !          2000: {
        !          2001:   defkey (GlobalMap, Ctl ('Z'), "suspend-emacs");
        !          2002:   defkey (CtlXmap, Ctl ('Z'), "suspend-emacs");
        !          2003:   defkey (ESCmap, Ctl ('C'), "exit-recursive-edit");
        !          2004:   defkey (GlobalMap, Ctl (']'), "abort-recursive-edit");
        !          2005:   defkey (ESCmap, 'x', "execute-extended-command");
        !          2006: }

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