File:  [gforth] / gforth / engine / io.c
Revision 1.42: download - view: text, annotated - select for diffs
Tue Apr 3 22:57:00 2012 UTC (9 years, 5 months ago) by pazsan
Branches: MAIN
CVS tags: HEAD
Check key_avail again with FIONREAD when isatty is true - but properly fall back to select when this is false

    1: /* direct key io driver
    2: 
    3:   Copyright (C) 1995,1996,1997,1998,1999,2002,2003,2006,2007,2008,2009,2010 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 3
   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, see http://www.gnu.org/licenses/.
   19: 
   20:   The following is stolen from the readline library for bash
   21: */
   22: 
   23: /*
   24:    Use -D_POSIX_VERSION for POSIX systems.
   25: */
   26: 
   27: #include "config.h"
   28: #include "forth.h"
   29: #include <sys/time.h>
   30: #include <sys/types.h>
   31: #include <unistd.h>
   32: 
   33: #if defined(apollo) || defined(_WIN32)
   34: #define _POSIX_VERSION
   35: #endif
   36: 
   37: #if !defined(Solaris) && defined(sun) && defined(__svr4__)
   38: #define Solaris
   39: typedef unsigned int uint32_t;
   40: #endif
   41: 
   42: #include <stdlib.h>
   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: void prep_terminal ()
  451: {
  452:   int tty = fileno (stdin);
  453: #if defined (TERMIOS_TTY_DRIVER)
  454:   struct termios tio;
  455: #else
  456:   struct termio tio;
  457: #endif /* !TERMIOS_TTY_DRIVER */
  458: 
  459: #if defined (HAVE_POSIX_SIGNALS)
  460:   sigset_t set, oset;
  461: #else
  462: #  if defined (HAVE_BSD_SIGNALS)
  463:   int oldmask;
  464: #  endif /* HAVE_BSD_SIGNALS */
  465: #endif /* !HAVE_POSIX_SIGNALS */
  466: 
  467:   if (terminal_prepped)
  468:     return;
  469: 
  470:   if (!isatty(tty))  {     /* added by MdG */
  471:     terminal_prepped = 1;      /* added by MdG */
  472:     return;      /* added by MdG */
  473:   }      /* added by MdG */
  474:    
  475:   /* Try to keep this function from being INTerrupted.  We can do it
  476:      on POSIX and systems with BSD-like signal handling. */
  477: #if defined (HAVE_POSIX_SIGNALS)
  478:   sigemptyset (&set);
  479:   sigemptyset (&oset);
  480:   sigaddset (&set, SIGINT);
  481:   sigprocmask (SIG_BLOCK, &set, &oset);
  482: #else /* !HAVE_POSIX_SIGNALS */
  483: #  if defined (HAVE_BSD_SIGNALS)
  484:   oldmask = sigblock (sigmask (SIGINT));
  485: #  endif /* HAVE_BSD_SIGNALS */
  486: #endif /* !HAVE_POSIX_SIGNALS */
  487: 
  488: #if defined (TERMIOS_TTY_DRIVER)
  489:   tcgetattr (tty, &tio);
  490: #else
  491:   ioctl (tty, TCGETA, &tio);
  492: #endif /* !TERMIOS_TTY_DRIVER */
  493: 
  494:   otio = tio;
  495: 
  496:   readline_echoing_p = (tio.c_lflag & ECHO);
  497: 
  498:   tio.c_lflag &= ~(ICANON | ECHO);
  499: 
  500:   if (otio.c_cc[VEOF] != _POSIX_VDISABLE)
  501:     eof_char = otio.c_cc[VEOF];
  502: 
  503: #if defined (USE_XON_XOFF)
  504: #if defined (IXANY)
  505:   tio.c_iflag &= ~(IXON | IXOFF | IXANY);
  506: #else
  507:   /* `strict' Posix systems do not define IXANY. */
  508:   tio.c_iflag &= ~(IXON | IXOFF);
  509: #endif /* IXANY */
  510: #endif /* USE_XON_XOFF */
  511: 
  512:   /* Only turn this off if we are using all 8 bits. */
  513:   if ((tio.c_cflag & CSIZE) == CS8)
  514:     tio.c_iflag &= ~(ISTRIP | INPCK);
  515: 
  516:   /* Make sure we differentiate between CR and NL on input. */
  517:   tio.c_iflag &= ~(ICRNL | INLCR);
  518: 
  519: #if !defined (HANDLE_SIGNALS)
  520:   tio.c_lflag &= ~ISIG;
  521: #else
  522:   tio.c_lflag |= ISIG;
  523: #endif
  524: 
  525:   tio.c_cc[VMIN] = 1;
  526:   tio.c_cc[VTIME] = 0;
  527: 
  528:   /* Turn off characters that we need on Posix systems with job control,
  529:      just to be sure.  This includes ^Y and ^V.  This should not really
  530:      be necessary.  */
  531: #if defined (TERMIOS_TTY_DRIVER) && defined (_POSIX_JOB_CONTROL)
  532: 
  533: #if defined (VLNEXT)
  534:   tio.c_cc[VLNEXT] = _POSIX_VDISABLE;
  535: #endif
  536: 
  537: #if defined (VDSUSP)
  538:   tio.c_cc[VDSUSP] = _POSIX_VDISABLE;
  539: #endif
  540: 
  541: #endif /* POSIX && JOB_CONTROL */
  542: 
  543: #if defined (TERMIOS_TTY_DRIVER)
  544:   tcsetattr (tty, TCSADRAIN, &tio);
  545:   tcflow (tty, TCOON);		/* Simulate a ^Q. */
  546: #else
  547:   ioctl (tty, TCSETAW, &tio);
  548:   ioctl (tty, TCXONC, 1);	/* Simulate a ^Q. */
  549: #endif /* !TERMIOS_TTY_DRIVER */
  550: 
  551:   terminal_prepped = 1;
  552: 
  553: #if defined (HAVE_POSIX_SIGNALS)
  554:   sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
  555: #else
  556: #  if defined (HAVE_BSD_SIGNALS)
  557:   sigsetmask (oldmask);
  558: #  endif /* HAVE_BSD_SIGNALS */
  559: #endif /* !HAVE_POSIX_SIGNALS */
  560: }
  561: 
  562: void deprep_terminal ()
  563: {
  564:   int tty = fileno (stdin);
  565: 
  566:   /* Try to keep this function from being INTerrupted.  We can do it
  567:      on POSIX and systems with BSD-like signal handling. */
  568: #if defined (HAVE_POSIX_SIGNALS)
  569:   sigset_t set, oset;
  570: #else /* !HAVE_POSIX_SIGNALS */
  571: #  if defined (HAVE_BSD_SIGNALS)
  572:   int oldmask;
  573: #  endif /* HAVE_BSD_SIGNALS */
  574: #endif /* !HAVE_POSIX_SIGNALS */
  575: 
  576:   if (!terminal_prepped)
  577:     return;
  578: 
  579: /* Added by MdG */
  580:   if (!isatty(tty)) {
  581:     terminal_prepped = 0;
  582:     return;
  583:   }
  584: 
  585: #if defined (HAVE_POSIX_SIGNALS)
  586:   sigemptyset (&set);
  587:   sigemptyset (&oset);
  588:   sigaddset (&set, SIGINT);
  589:   sigprocmask (SIG_BLOCK, &set, &oset);
  590: #else /* !HAVE_POSIX_SIGNALS */
  591: #  if defined (HAVE_BSD_SIGNALS)
  592:   oldmask = sigblock (sigmask (SIGINT));
  593: #  endif /* HAVE_BSD_SIGNALS */
  594: #endif /* !HAVE_POSIX_SIGNALS */
  595: 
  596: #if defined (TERMIOS_TTY_DRIVER)
  597:   tcsetattr (tty, TCSADRAIN, &otio);
  598:   tcflow (tty, TCOON);		/* Simulate a ^Q. */
  599: #else /* TERMIOS_TTY_DRIVER */
  600:   ioctl (tty, TCSETAW, &otio);
  601:   ioctl (tty, TCXONC, 1);	/* Simulate a ^Q. */
  602: #endif /* !TERMIOS_TTY_DRIVER */
  603: 
  604:   terminal_prepped = 0;
  605: 
  606: #if defined (HAVE_POSIX_SIGNALS)
  607:   sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
  608: #else /* !HAVE_POSIX_SIGNALS */
  609: #  if defined (HAVE_BSD_SIGNALS)
  610:   sigsetmask (oldmask);
  611: #  endif /* HAVE_BSD_SIGNALS */
  612: #endif /* !HAVE_POSIX_SIGNALS */
  613: }
  614: #endif  /* NEW_TTY_DRIVER */
  615: 
  616: /* an ungetc() variant where we can know that there is a character waiting:
  617:    gf_ungetc: like ungetc
  618:    gf_regetc: call when reading a char, but does not get the character
  619:    gf_ungottenc: true if there is a char waiting
  620: 
  621:    Implementation: just an array containing all the FILEs with ungotten chars.
  622:    Sequential search for membership checking (there should not be many elements)
  623: */
  624: 
  625: static FILE **ungotten_files = NULL;
  626: static size_t n_ungotten = 0; /* actual number */
  627: static size_t max_ungotten = 0; /* buffer size */
  628: 
  629: int gf_ungetc(int c, FILE *stream)
  630: /* like ungetc, but works with the others */
  631: {
  632:   if (n_ungotten>=max_ungotten) {
  633:     max_ungotten = max_ungotten*2+1;
  634:     ungotten_files = realloc(ungotten_files, max_ungotten*sizeof(FILE *));
  635:   }
  636:   ungotten_files[n_ungotten++] = stream;
  637:   return ungetc(c, stream);
  638: }
  639: 
  640: static long search_ungotten(FILE *stream)
  641: {
  642:   long i;
  643:   for (i=0; i<n_ungotten; i++)
  644:     if (ungotten_files[i] == stream)
  645:       return i;
  646:   return -1;
  647: }
  648: 
  649: void gf_regetc(FILE *stream)
  650: /* remove STREAM from ungotten_files */
  651: {
  652:   long i = search_ungotten(stream);
  653:   if (i>=0)
  654:     ungotten_files[i] = ungotten_files[--n_ungotten];
  655: }
  656: 
  657: int gf_ungottenc(FILE *stream)
  658: /* true if stream has been ungotten */
  659: {
  660:   return search_ungotten(stream)>=0;
  661: }
  662: 
  663: long key_avail (FILE *stream)
  664: {
  665:   int tty = fileno (stream);
  666:   fd_set selin;
  667:   static struct timeval now = { 0 , 0 };
  668:   int chars_avail;
  669: 
  670:   if (gf_ungottenc(stream))
  671:     return 1;
  672:   setvbuf(stream, NULL, _IONBF, 0);
  673:   if(!terminal_prepped && stream == stdin)
  674:     prep_terminal();
  675: 
  676: #if defined(FIONREAD) && !defined(_WIN32)
  677:   if(isatty (tty)) {
  678:     int result = ioctl (tty, FIONREAD, &chars_avail);
  679:   } else
  680: #endif
  681:   {
  682:     FD_ZERO(&selin);
  683:     FD_SET(tty, &selin);
  684:     chars_avail = select(1, &selin, NULL, NULL, &now);
  685:   }
  686:   if (chars_avail > 0) {
  687:     /* getc won't block */
  688:     int c = getc(stream);
  689:     if (c==EOF)
  690:       return 0;
  691:     gf_ungetc(c, stream);
  692:   }
  693:   return (chars_avail == -1) ? 0 : chars_avail;
  694: }
  695: 
  696: /* Get a key from the buffer of characters to be read.
  697:    Return the key in KEY.
  698:    Result is KEY if there was a key, or 0 if there wasn't. */
  699: 
  700: /* When compiling and running in the `Posix' environment, Ultrix does
  701:    not restart system calls, so this needs to do it. */
  702: 
  703: Cell getkey(FILE * stream)
  704: {
  705:   Cell result;
  706:   unsigned char c;
  707: 
  708:   if (!gf_ungottenc(stream))
  709:     setvbuf(stream, NULL, _IONBF, 0);
  710:   if(!terminal_prepped && stream == stdin)
  711:     prep_terminal();
  712: 
  713:   result = fread(&c, sizeof(c), 1, stream);
  714:   if (result>0)
  715:     gf_regetc(stream);
  716:   return result==0 ? (errno == EINTR ? 12 : 4) : c;
  717: }
  718: 
  719: #ifdef STANDALONE
  720: void emit_char(char x)
  721: {
  722:   putc(x, stdout);
  723: }
  724: 
  725: void type_chars(char *addr, unsigned int l)
  726: {
  727:   fwrite(addr, l, 1, stdout);
  728: }
  729: #endif
  730: 
  731: #ifdef TEST
  732: 
  733: #include <time.h>
  734: 
  735: int timewait=100000;
  736: 
  737: int main()
  738: {
  739: 	unsigned char c;
  740: 
  741: 	prep_terminal();
  742: 
  743: 	do
  744: 	{
  745: 		int i=0;
  746: 
  747: 		while(!key_avail(stdin))
  748: 		{
  749: 			printf("%04d",i);
  750: 			fflush(stdout);
  751: 			{
  752: 				struct timeval timeout;
  753: 				timeout.tv_sec=timewait/1000000;
  754: 				timeout.tv_usec=timewait%1000000;
  755: 				(void)select(0,0,0,0,&timeout);
  756: 			}
  757: 			i++;
  758: 			printf("\b\b\b\b");
  759: 			fflush(stdout);
  760: 		}
  761: 		c = getkey(stdin);
  762: 		printf("%02x,",(int)c);
  763: 		fflush(stdout);
  764: 	}	while(c != 0x1B);
  765: 
  766: 	deprep_terminal();
  767: 	puts("");
  768: }
  769: #endif
  770: #endif /* MSDOS */
  771: 

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