File:  [gforth] / gforth / engine / io.c
Revision 1.20: download - view: text, annotated - select for diffs
Sun Apr 9 07:39:07 2006 UTC (15 years, 5 months ago) by anton
Branches: MAIN
CVS tags: HEAD
prep_terminal() only for stdin KEY-FILE?

    1: /* direct key io driver
    2: 
    3:   Copyright (C) 1995,1996,1997,1998,1999,2002,2003 Free Software Foundation, Inc.
    4: 
    5:   This file is part of Gforth.
    6: 
    7:   Gforth is free software; you can redistribute it and/or
    8:   modify it under the terms of the GNU General Public License
    9:   as published by the Free Software Foundation; either version 2
   10:   of the License, or (at your option) any later version.
   11: 
   12:   This program is distributed in the hope that it will be useful,
   13:   but WITHOUT ANY WARRANTY; without even the implied warranty of
   14:   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15:   GNU General Public License for more details.
   16: 
   17:   You should have received a copy of the GNU General Public License
   18:   along with this program; if not, write to the Free Software
   19:   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
   20: 
   21:   The following is stolen from the readline library for bash
   22: */
   23: 
   24: /*
   25:    Use -D_POSIX_VERSION for POSIX systems.
   26: */
   27: 
   28: #include "config.h"
   29: #include "forth.h"
   30: #include <sys/time.h>
   31: #include <sys/types.h>
   32: #include <unistd.h>
   33: 
   34: #if defined(apollo) || defined(_WIN32)
   35: #define _POSIX_VERSION
   36: #endif
   37: 
   38: #if !defined(Solaris) && defined(sun) && defined(__svr4__)
   39: #define Solaris
   40: typedef unsigned int uint32_t;
   41: #endif
   42: 
   43: #include <stdio.h>
   44: #include <signal.h>
   45: #include <string.h>
   46: #if !defined(apollo) && !defined(MSDOS)
   47: #include <sys/ioctl.h>
   48: #endif
   49: #include <fcntl.h>
   50: #include <sys/file.h>
   51: #if defined(Solaris) && !defined(FIONREAD)
   52: #include <sys/filio.h>
   53: #endif
   54: #include <setjmp.h>
   55: #include "io.h"
   56: 
   57: #ifndef MSDOS
   58: #if defined (__GNUC__)
   59: #  define alloca __builtin_alloca
   60: #else
   61: #  if defined (sparc) || defined (HAVE_ALLOCA_H)
   62: #    include <alloca.h>
   63: #  endif
   64: #endif
   65: 
   66: #define NEW_TTY_DRIVER
   67: #define HAVE_BSD_SIGNALS
   68: /*
   69: #ifndef apollo
   70: #define USE_XON_XOFF
   71: #endif
   72: */
   73: 
   74: #define HANDLE_SIGNALS
   75: 
   76: /* Some USG machines have BSD signal handling (sigblock, sigsetmask, etc.) */
   77: #if defined (USG) && !defined (hpux)
   78: #undef HAVE_BSD_SIGNALS
   79: #endif
   80: 
   81: /* System V machines use termio. */
   82: #if !defined (_POSIX_VERSION)
   83: #  if defined (USG) || defined (hpux) || defined (Xenix) || defined (sgi) || defined (DGUX) || defined (ultrix) || defined (Solaris) || defined(_WIN32)
   84: #    undef NEW_TTY_DRIVER
   85: #    define TERMIO_TTY_DRIVER
   86: #    include <termio.h>
   87: #    if !defined (TCOON)
   88: #      define TCOON 1
   89: #    endif
   90: #  endif /* USG || hpux || Xenix || sgi || DUGX || ultrix*/
   91: #endif /* !_POSIX_VERSION */
   92: 
   93: /* Posix systems use termios and the Posix signal functions. */
   94: #if defined (_POSIX_VERSION) || defined (NeXT)
   95: #  if !defined (TERMIOS_MISSING)
   96: #    undef NEW_TTY_DRIVER
   97: #    define TERMIOS_TTY_DRIVER
   98: #    include <termios.h>
   99: #  endif /* !TERMIOS_MISSING */
  100: #endif /* _POSIX_VERSION || NeXT */
  101: 
  102: #if defined (_POSIX_VERSION)
  103: #  define HAVE_POSIX_SIGNALS
  104: #  if !defined (O_NDELAY)
  105: #    define O_NDELAY O_NONBLOCK	/* Posix-style non-blocking i/o */
  106: #  endif /* O_NDELAY */
  107: #endif /* _POSIX_VERSION */
  108: 
  109: /* Other (BSD) machines use sgtty. */
  110: #if defined (NEW_TTY_DRIVER)
  111: #include <sgtty.h>
  112: #endif
  113: 
  114: /* Define _POSIX_VDISABLE if we are not using the `new' tty driver and
  115:    it is not already defined.  It is used both to determine if a
  116:    special character is disabled and to disable certain special
  117:    characters.  Posix systems should set to 0, USG systems to -1. */
  118: #if !defined (NEW_TTY_DRIVER) && !defined (_POSIX_VDISABLE)
  119: #  if defined (_POSIX_VERSION) || defined (NeXT)
  120: #    define _POSIX_VDISABLE 0
  121: #  else /* !_POSIX_VERSION */
  122: #    define _POSIX_VDISABLE -1
  123: #  endif /* !_POSIX_VERSION */
  124: #endif /* !NEW_TTY_DRIVER && !_POSIX_VDISABLE */
  125: 
  126: #include <errno.h>
  127: /* extern int errno; */
  128: 
  129: #if defined (SHELL)
  130: #  include <posixstat.h>
  131: #else
  132: #  include <sys/stat.h>
  133: #endif /* !SHELL */
  134: /* #define HACK_TERMCAP_MOTION */
  135: 
  136: #if defined (USG) && defined (hpux)
  137: #  if !defined (USGr3)
  138: #    define USGr3
  139: #  endif /* USGr3 */
  140: #endif /* USG && hpux */
  141: 
  142: #if (defined (_POSIX_VERSION) || defined (USGr3)) && !defined(apollo)
  143: #  include <dirent.h>
  144: #  define direct dirent
  145: #  if defined (_POSIX_VERSION)
  146: #    define D_NAMLEN(d) (strlen ((d)->d_name))
  147: #  else /* !_POSIX_VERSION */
  148: #    define D_NAMLEN(d) ((d)->d_reclen)
  149: #  endif /* !_POSIX_VERSION */
  150: #else /* !_POSIX_VERSION && !USGr3 */
  151: #  define D_NAMLEN(d) ((d)->d_namlen)
  152: #  if !defined (USG)
  153: #    include <sys/dir.h>
  154: #  else /* USG */
  155: #    if defined (Xenix)
  156: #      include <sys/ndir.h>
  157: #    else /* !Xenix */
  158: #      include <ndir.h>
  159: #    endif /* !Xenix */
  160: #  endif /* USG */
  161: #endif /* !POSIX_VERSION && !USGr3 */
  162: 
  163: #if defined (USG) && defined (TIOCGWINSZ)
  164: #  include <sys/stream.h>
  165: #  if defined (USGr4) || defined (USGr3)
  166: #    if defined (Symmetry) || defined (_SEQUENT_)
  167: #      include <sys/pte.h>
  168: #    else
  169: #      include <sys/ptem.h>
  170: #    endif /* !Symmetry || _SEQUENT_ */
  171: #  endif /* USGr4 */
  172: #endif /* USG && TIOCGWINSZ */
  173: 
  174: #if defined (TERMIOS_TTY_DRIVER)
  175: static struct termios otio;
  176: #else
  177: static struct termio otio;
  178: #endif /* !TERMIOS_TTY_DRIVER */
  179: 
  180: /* Non-zero means echo characters as they are read. */
  181: int readline_echoing_p = 1;
  182: 
  183: /* The character that can generate an EOF.  Really read from
  184:    the terminal driver... just defaulted here. */
  185: 
  186: #ifndef CTRL
  187: #define CTRL(key)	((key)-'@')
  188: #endif
  189: 
  190: static int eof_char = CTRL ('D');
  191: 
  192: /* **************************************************************** */
  193: /*								    */
  194: /*		      Saving and Restoring the TTY	    	    */
  195: /*								    */
  196: /* **************************************************************** */
  197: 
  198: /* Non-zero means that the terminal is in a prepped state. */
  199: int terminal_prepped = 0;
  200: 
  201: #if defined (NEW_TTY_DRIVER)
  202: 
  203: /* Standard flags, including ECHO. */
  204: static int original_tty_flags = 0;
  205: 
  206: /* Local mode flags, like LPASS8. */
  207: static int local_mode_flags = 0;
  208: 
  209: /* Terminal characters.  This has C-s and C-q in it. */
  210: static struct tchars original_tchars;
  211: 
  212: /* Local special characters.  This has the interrupt characters in it. */
  213: #if defined (TIOCGLTC)
  214: static struct ltchars original_ltchars;
  215: #endif
  216: 
  217: /* Bind KEY to FUNCTION.  Returns non-zero if KEY is out of range. */
  218: 
  219: #if defined (TIOCGETC)
  220: #if defined (USE_XON_XOFF)
  221: 
  222: int
  223: bind_key (key, function)
  224:      int key;
  225:      Function *function;
  226: {
  227:   if (key < 0)
  228:     return (key);
  229: 
  230:   if (key > 127 && key < 256)
  231:     {
  232:       if (keymap[ESC].type == ISKMAP)
  233: 	{
  234: 	  Keymap escmap = (Keymap)keymap[ESC].function;
  235: 
  236: 	  key -= 128;
  237: 	  escmap[key].type = ISFUNC;
  238: 	  escmap[key].function = function;
  239: 	  return (0);
  240: 	}
  241:       return (key);
  242:     }
  243: 
  244:   keymap[key].type = ISFUNC;
  245:   keymap[key].function = function;
  246:  return (0);
  247: }
  248: #endif
  249: #endif
  250: 
  251: /* We use this to get and set the tty_flags. */
  252: static struct sgttyb the_ttybuff;
  253: 
  254: #if defined (USE_XON_XOFF)
  255: /* If the terminal was in xoff state when we got to it, then xon_char
  256:    contains the character that is supposed to start it again. */
  257: static int xon_char, xoff_state;
  258: #endif /* USE_XON_XOFF */
  259: 
  260: /* **************************************************************** */
  261: /*								    */
  262: /*			Bogus Flow Control      		    */
  263: /*								    */
  264: /* **************************************************************** */
  265: 
  266: restart_output (count, key)
  267:      int count, key;
  268: {
  269:   int fildes = fileno (stdin);
  270: #if defined (TIOCSTART)
  271: #if defined (apollo)
  272:   ioctl (&fildes, TIOCSTART, 0);
  273: #else
  274:   ioctl (fildes, TIOCSTART, 0);
  275: #endif /* apollo */
  276: 
  277: #else
  278: #  if defined (TERMIOS_TTY_DRIVER)
  279:         tcflow (fildes, TCOON);
  280: #  else
  281: #    if defined (TCXONC)
  282:         ioctl (fildes, TCXONC, TCOON);
  283: #    endif /* TCXONC */
  284: #  endif /* !TERMIOS_TTY_DRIVER */
  285: #endif /* TIOCSTART */
  286: }
  287: 
  288: /* Put the terminal in CBREAK mode so that we can detect key presses. */
  289: void prep_terminal ()
  290: {
  291:   int tty = fileno (stdin);
  292: #if defined (HAVE_BSD_SIGNALS)
  293:   int oldmask;
  294: #endif /* HAVE_BSD_SIGNALS */
  295: 
  296:   if (terminal_prepped)
  297:     return;
  298: 
  299:   if (!isatty(tty)) {      /* added by MdG */
  300:     terminal_prepped = 1;      /* added by MdG */
  301:     return;      /* added by MdG */
  302:   }      /* added by MdG */
  303:    
  304:   oldmask = sigblock (sigmask (SIGINT));
  305: 
  306:   /* We always get the latest tty values.  Maybe stty changed them. */
  307:   ioctl (tty, TIOCGETP, &the_ttybuff);
  308:   original_tty_flags = the_ttybuff.sg_flags;
  309: 
  310:   readline_echoing_p = (original_tty_flags & ECHO);
  311: 
  312: #if defined (TIOCLGET)
  313:   ioctl (tty, TIOCLGET, &local_mode_flags);
  314: #endif
  315: 
  316: #if !defined (ANYP)
  317: #  define ANYP (EVENP | ODDP)
  318: #endif
  319: 
  320:   /* If this terminal doesn't care how the 8th bit is used,
  321:      then we can use it for the meta-key.  We check by seeing
  322:      if BOTH odd and even parity are allowed. */
  323:   if (the_ttybuff.sg_flags & ANYP)
  324:     {
  325: #if defined (PASS8)
  326:       the_ttybuff.sg_flags |= PASS8;
  327: #endif
  328: 
  329:       /* Hack on local mode flags if we can. */
  330: #if defined (TIOCLGET) && defined (LPASS8)
  331:       {
  332: 	int flags;
  333: 	flags = local_mode_flags | LPASS8;
  334: 	ioctl (tty, TIOCLSET, &flags);
  335:       }
  336: #endif /* TIOCLGET && LPASS8 */
  337:     }
  338: 
  339: #if defined (TIOCGETC)
  340:   {
  341:     struct tchars temp;
  342: 
  343:     ioctl (tty, TIOCGETC, &original_tchars);
  344:     temp = original_tchars;
  345: 
  346: #if defined (USE_XON_XOFF)
  347:     /* Get rid of C-s and C-q.
  348:        We remember the value of startc (C-q) so that if the terminal is in
  349:        xoff state, the user can xon it by pressing that character. */
  350:     xon_char = temp.t_startc;
  351:     temp.t_stopc = -1;
  352:     temp.t_startc = -1;
  353: 
  354:     /* If there is an XON character, bind it to restart the output. */
  355:     if (xon_char != -1)
  356:       bind_key (xon_char, restart_output);
  357: #endif /* USE_XON_XOFF */
  358: 
  359:     /* If there is an EOF char, bind eof_char to it. */
  360:     if (temp.t_eofc != -1)
  361:       eof_char = temp.t_eofc;
  362: 
  363: #if defined (NO_KILL_INTR)
  364:     /* Get rid of C-\ and C-c. */
  365:     temp.t_intrc = temp.t_quitc = -1;
  366: #endif /* NO_KILL_INTR */
  367: 
  368:     ioctl (tty, TIOCSETC, &temp);
  369:   }
  370: #endif /* TIOCGETC */
  371: 
  372: #if defined (TIOCGLTC)
  373:   {
  374:     struct ltchars temp;
  375: 
  376:     ioctl (tty, TIOCGLTC, &original_ltchars);
  377:     temp = original_ltchars;
  378: 
  379:     /* Make the interrupt keys go away.  Just enough to make people
  380:        happy. */
  381:     temp.t_dsuspc = -1;	/* C-y */
  382:     temp.t_lnextc = -1;	/* C-v */
  383: 
  384:     ioctl (tty, TIOCSLTC, &temp);
  385:   }
  386: #endif /* TIOCGLTC */
  387: 
  388:   the_ttybuff.sg_flags &= ~(ECHO | CRMOD);
  389:   the_ttybuff.sg_flags |= CBREAK;
  390:   ioctl (tty, TIOCSETN, &the_ttybuff);
  391: 
  392:   terminal_prepped = 1;
  393: 
  394: #if defined (HAVE_BSD_SIGNALS)
  395:   sigsetmask (oldmask);
  396: #endif
  397: }
  398: 
  399: /* Restore the terminal to its original state. */
  400: void deprep_terminal ()
  401: {
  402:   int tty = fileno (stdin);
  403: #if defined (HAVE_BSD_SIGNALS)
  404:   int oldmask;
  405: #endif
  406: 
  407:   if (!terminal_prepped)
  408:     return;
  409: 
  410: /* Added by MdG */
  411:   if (!isatty(tty)) {
  412:     terminal_prepped = 0;
  413:     return;
  414:   }
  415:    
  416:   oldmask = sigblock (sigmask (SIGINT));
  417: 
  418:   the_ttybuff.sg_flags = original_tty_flags;
  419:   ioctl (tty, TIOCSETN, &the_ttybuff);
  420:   readline_echoing_p = 1;
  421: 
  422: #if defined (TIOCLGET)
  423:   ioctl (tty, TIOCLSET, &local_mode_flags);
  424: #endif
  425: 
  426: #if defined (TIOCSLTC)
  427:   ioctl (tty, TIOCSLTC, &original_ltchars);
  428: #endif
  429: 
  430: #if defined (TIOCSETC)
  431:   ioctl (tty, TIOCSETC, &original_tchars);
  432: #endif
  433:   terminal_prepped = 0;
  434: 
  435: #if defined (HAVE_BSD_SIGNALS)
  436:   sigsetmask (oldmask);
  437: #endif
  438: }
  439: 
  440: #else  /* !defined (NEW_TTY_DRIVER) */
  441: 
  442: #if !defined (VMIN)
  443: #define VMIN VEOF
  444: #endif
  445: 
  446: #if !defined (VTIME)
  447: #define VTIME VEOL
  448: #endif
  449: 
  450: #include <locale.h>
  451: 
  452: void prep_terminal ()
  453: {
  454:   int tty = fileno (stdin);
  455: #if defined (TERMIOS_TTY_DRIVER)
  456:   struct termios tio;
  457: #else
  458:   struct termio tio;
  459: #endif /* !TERMIOS_TTY_DRIVER */
  460: 
  461: #if defined (HAVE_POSIX_SIGNALS)
  462:   sigset_t set, oset;
  463: #else
  464: #  if defined (HAVE_BSD_SIGNALS)
  465:   int oldmask;
  466: #  endif /* HAVE_BSD_SIGNALS */
  467: #endif /* !HAVE_POSIX_SIGNALS */
  468: 
  469:   if (terminal_prepped)
  470:     return;
  471: 
  472:   if (!isatty(tty))  {     /* added by MdG */
  473:     terminal_prepped = 1;      /* added by MdG */
  474:     return;      /* added by MdG */
  475:   }      /* added by MdG */
  476:    
  477:   setlocale(LC_ALL, "");
  478: 
  479:   /* Try to keep this function from being INTerrupted.  We can do it
  480:      on POSIX and systems with BSD-like signal handling. */
  481: #if defined (HAVE_POSIX_SIGNALS)
  482:   sigemptyset (&set);
  483:   sigemptyset (&oset);
  484:   sigaddset (&set, SIGINT);
  485:   sigprocmask (SIG_BLOCK, &set, &oset);
  486: #else /* !HAVE_POSIX_SIGNALS */
  487: #  if defined (HAVE_BSD_SIGNALS)
  488:   oldmask = sigblock (sigmask (SIGINT));
  489: #  endif /* HAVE_BSD_SIGNALS */
  490: #endif /* !HAVE_POSIX_SIGNALS */
  491: 
  492: #if defined (TERMIOS_TTY_DRIVER)
  493:   tcgetattr (tty, &tio);
  494: #else
  495:   ioctl (tty, TCGETA, &tio);
  496: #endif /* !TERMIOS_TTY_DRIVER */
  497: 
  498:   otio = tio;
  499: 
  500:   readline_echoing_p = (tio.c_lflag & ECHO);
  501: 
  502:   tio.c_lflag &= ~(ICANON | ECHO);
  503: 
  504:   if (otio.c_cc[VEOF] != _POSIX_VDISABLE)
  505:     eof_char = otio.c_cc[VEOF];
  506: 
  507: #if defined (USE_XON_XOFF)
  508: #if defined (IXANY)
  509:   tio.c_iflag &= ~(IXON | IXOFF | IXANY);
  510: #else
  511:   /* `strict' Posix systems do not define IXANY. */
  512:   tio.c_iflag &= ~(IXON | IXOFF);
  513: #endif /* IXANY */
  514: #endif /* USE_XON_XOFF */
  515: 
  516:   /* Only turn this off if we are using all 8 bits. */
  517:   if ((tio.c_cflag & CSIZE) == CS8)
  518:     tio.c_iflag &= ~(ISTRIP | INPCK);
  519: 
  520:   /* Make sure we differentiate between CR and NL on input. */
  521:   tio.c_iflag &= ~(ICRNL | INLCR);
  522: 
  523: #if !defined (HANDLE_SIGNALS)
  524:   tio.c_lflag &= ~ISIG;
  525: #else
  526:   tio.c_lflag |= ISIG;
  527: #endif
  528: 
  529:   tio.c_cc[VMIN] = 1;
  530:   tio.c_cc[VTIME] = 0;
  531: 
  532:   /* Turn off characters that we need on Posix systems with job control,
  533:      just to be sure.  This includes ^Y and ^V.  This should not really
  534:      be necessary.  */
  535: #if defined (TERMIOS_TTY_DRIVER) && defined (_POSIX_JOB_CONTROL)
  536: 
  537: #if defined (VLNEXT)
  538:   tio.c_cc[VLNEXT] = _POSIX_VDISABLE;
  539: #endif
  540: 
  541: #if defined (VDSUSP)
  542:   tio.c_cc[VDSUSP] = _POSIX_VDISABLE;
  543: #endif
  544: 
  545: #endif /* POSIX && JOB_CONTROL */
  546: 
  547: #if defined (TERMIOS_TTY_DRIVER)
  548:   tcsetattr (tty, TCSADRAIN, &tio);
  549:   tcflow (tty, TCOON);		/* Simulate a ^Q. */
  550: #else
  551:   ioctl (tty, TCSETAW, &tio);
  552:   ioctl (tty, TCXONC, 1);	/* Simulate a ^Q. */
  553: #endif /* !TERMIOS_TTY_DRIVER */
  554: 
  555:   terminal_prepped = 1;
  556: 
  557: #if defined (HAVE_POSIX_SIGNALS)
  558:   sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
  559: #else
  560: #  if defined (HAVE_BSD_SIGNALS)
  561:   sigsetmask (oldmask);
  562: #  endif /* HAVE_BSD_SIGNALS */
  563: #endif /* !HAVE_POSIX_SIGNALS */
  564: }
  565: 
  566: void deprep_terminal ()
  567: {
  568:   int tty = fileno (stdin);
  569: 
  570:   /* Try to keep this function from being INTerrupted.  We can do it
  571:      on POSIX and systems with BSD-like signal handling. */
  572: #if defined (HAVE_POSIX_SIGNALS)
  573:   sigset_t set, oset;
  574: #else /* !HAVE_POSIX_SIGNALS */
  575: #  if defined (HAVE_BSD_SIGNALS)
  576:   int oldmask;
  577: #  endif /* HAVE_BSD_SIGNALS */
  578: #endif /* !HAVE_POSIX_SIGNALS */
  579: 
  580:   if (!terminal_prepped)
  581:     return;
  582: 
  583: /* Added by MdG */
  584:   if (!isatty(tty)) {
  585:     terminal_prepped = 0;
  586:     return;
  587:   }
  588: 
  589: #if defined (HAVE_POSIX_SIGNALS)
  590:   sigemptyset (&set);
  591:   sigemptyset (&oset);
  592:   sigaddset (&set, SIGINT);
  593:   sigprocmask (SIG_BLOCK, &set, &oset);
  594: #else /* !HAVE_POSIX_SIGNALS */
  595: #  if defined (HAVE_BSD_SIGNALS)
  596:   oldmask = sigblock (sigmask (SIGINT));
  597: #  endif /* HAVE_BSD_SIGNALS */
  598: #endif /* !HAVE_POSIX_SIGNALS */
  599: 
  600: #if defined (TERMIOS_TTY_DRIVER)
  601:   tcsetattr (tty, TCSADRAIN, &otio);
  602:   tcflow (tty, TCOON);		/* Simulate a ^Q. */
  603: #else /* TERMIOS_TTY_DRIVER */
  604:   ioctl (tty, TCSETAW, &otio);
  605:   ioctl (tty, TCXONC, 1);	/* Simulate a ^Q. */
  606: #endif /* !TERMIOS_TTY_DRIVER */
  607: 
  608:   terminal_prepped = 0;
  609: 
  610: #if defined (HAVE_POSIX_SIGNALS)
  611:   sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
  612: #else /* !HAVE_POSIX_SIGNALS */
  613: #  if defined (HAVE_BSD_SIGNALS)
  614:   sigsetmask (oldmask);
  615: #  endif /* HAVE_BSD_SIGNALS */
  616: #endif /* !HAVE_POSIX_SIGNALS */
  617: }
  618: #endif  /* NEW_TTY_DRIVER */
  619: 
  620: /* If a character is available to be read, then read it
  621:    and stuff it into IBUFFER.  Otherwise, just return. */
  622: long pending = -1L;
  623: /* !! This is a bug: if key_avail(file1) is followed by getkey(file2),
  624:    the getkey(file2) can return the character from file1. - anton */
  625: 
  626: /* Moreover, key_avail and getkey bypass the buffering of the FILE *,
  627:    leading to unpleasant effects if KEY-FILE and KEY?-FILE are mixed
  628:    with READ-FILE and READ-LINE */
  629: 
  630: long key_avail (FILE * stream)
  631: {
  632:   int tty = fileno (stream);
  633:   int chars_avail = pending;
  634:   int result;
  635: 
  636:   if(!terminal_prepped && stream == stdin)
  637:     prep_terminal();
  638: 
  639: #if defined(FIONREAD) && !defined(_WIN32)
  640:   /* !! What is the point of this part? it does not affect
  641:      chars_avail, and "result" is never used - anton */
  642:   if(isatty (tty)) {
  643:     result = ioctl (tty, FIONREAD, &chars_avail);
  644:   }
  645: #else
  646:   {
  647:     fd_set selin;
  648:     static int now[2] = { 0 , 0 };
  649:     int res;
  650:     
  651:     FD_ZERO(&selin);
  652:     FD_SET(tty, &selin);
  653:     chars_avail=select(1, &selin, NULL, NULL, now);
  654:   }
  655: #endif
  656:   
  657:   if(chars_avail == -1L) {
  658:     unsigned char inchar;
  659:     
  660:     fcntl(tty, F_SETFL, O_NDELAY);
  661:     result = read(tty, &inchar, sizeof(char));
  662:     if(result == sizeof(char)) {
  663:       chars_avail = 1;
  664:       pending = (long)inchar;
  665:     } else {
  666:       chars_avail = 0;
  667:     }
  668:     fcntl(tty, F_SETFL, 0);
  669:   }
  670: 
  671:   return chars_avail;
  672: }
  673: 
  674: /* Get a key from the buffer of characters to be read.
  675:    Return the key in KEY.
  676:    Result is KEY if there was a key, or 0 if there wasn't. */
  677: 
  678: /* When compiling and running in the `Posix' environment, Ultrix does
  679:    not restart system calls, so this needs to do it. */
  680: 
  681: Cell getkey(FILE * stream)
  682: {
  683:   Cell result;
  684:   unsigned char c;
  685: 
  686:   if(!terminal_prepped)
  687:     prep_terminal();
  688: 
  689:   while (pending < 0)
  690:     {
  691:       result = read (fileno (stream), &c, sizeof (char));
  692: 
  693:       if (result == sizeof (char))
  694:         return /* (c == 0x7F ? 0x08 :*/ c /*)*/;
  695: 
  696:       /* If zero characters are returned, then the file that we are
  697: 	 reading from is empty!  Return EOF in that case. */
  698:       if (result == 0)
  699: 	return (EOF);
  700: 
  701:       /* If the error that we received was SIGINT, then try again,
  702: 	 this is simply an interrupted system call to read ().
  703: 	 Otherwise, some error ocurred, also signifying EOF. */
  704:       if (errno != EINTR)
  705: 	return (EOF);
  706:     }
  707: 
  708:   /* otherwise there is a character pending;
  709:      return it and delete pending char */
  710:   result = (Cell) pending;
  711:   pending = -1L;
  712: 
  713:   return result;
  714: }
  715: 
  716: #ifdef TEST
  717: 
  718: #include <time.h>
  719: 
  720: int timewait=100000;
  721: 
  722: int main()
  723: {
  724: 	unsigned char c;
  725: 
  726: 	prep_terminal();
  727: 
  728: 	do
  729: 	{
  730: 		int i=0;
  731: 
  732: 		while(!key_avail(stdin))
  733: 		{
  734: 			printf("%04d",i);
  735: 			fflush(stdout);
  736: 			{
  737: 				struct timeval timeout;
  738: 				timeout.tv_sec=timewait/1000000;
  739: 				timeout.tv_usec=timewait%1000000;
  740: 				(void)select(0,0,0,0,&timeout);
  741: 			}
  742: 			i++;
  743: 			printf("\b\b\b\b");
  744: 			fflush(stdout);
  745: 		}
  746: 		c = getkey(stdin);
  747: 		printf("%02x,",(int)c);
  748: 		fflush(stdout);
  749: 	}	while(c != 0x1B);
  750: 
  751: 	deprep_terminal();
  752: 	puts("");
  753: }
  754: #endif
  755: #endif /* MSDOS */
  756: 

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