Return to io.c CVS log

Up to [gforth] / gforth

added answords.fs and strsignal.c
added checking of documenetation of ANS Forth words
Fixed many documentation errors and added some documentation
signal handling now uses strsignal and can handle signals not present on all machines

/*	direct key io driver

	The following is stolen from the readline library for bash
*/

/*
   Use -D_POSIX_VERSION for POSIX systems.
*/

#include <unistd.h>

#ifdef apollo
#define _POSIX_VERSION
#endif

#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <sys/types.h>
#ifndef apollo
#include <sys/ioctl.h>
#endif
#include <fcntl.h>
#include <sys/file.h>
#include <setjmp.h>
#include "forth.h"
#include "io.h"

#if defined (__GNUC__)
#  define alloca __builtin_alloca
#else
#  if defined (sparc) || defined (HAVE_ALLOCA_H)
#    include <alloca.h>
#  endif
#endif

#define NEW_TTY_DRIVER
#define HAVE_BSD_SIGNALS
/*
#ifndef apollo
#define USE_XON_XOFF
#endif
*/

#define HANDLE_SIGNALS

/* Some USG machines have BSD signal handling (sigblock, sigsetmask, etc.) */
#if defined (USG) && !defined (hpux)
#undef HAVE_BSD_SIGNALS
#endif

/* System V machines use termio. */
#if !defined (_POSIX_VERSION)
#  if defined (USG) || defined (hpux) || defined (Xenix) || defined (sgi) || defined (DGUX) || defined (ultrix) || defined (Solaris)
#    undef NEW_TTY_DRIVER
#    define TERMIO_TTY_DRIVER
#    include <termio.h>
#    if !defined (TCOON)
#      define TCOON 1
#    endif
#  endif /* USG || hpux || Xenix || sgi || DUGX || ultrix*/
#endif /* !_POSIX_VERSION */

/* Posix systems use termios and the Posix signal functions. */
#if defined (_POSIX_VERSION)
#  if !defined (TERMIOS_MISSING)
#    undef NEW_TTY_DRIVER
#    define TERMIOS_TTY_DRIVER
#    include <termios.h>
#  endif /* !TERMIOS_MISSING */
#  define HAVE_POSIX_SIGNALS
#  if !defined (O_NDELAY)
#    define O_NDELAY O_NONBLOCK	/* Posix-style non-blocking i/o */
#  endif /* O_NDELAY */
#endif /* _POSIX_VERSION */

/* Other (BSD) machines use sgtty. */
#if defined (NEW_TTY_DRIVER)
#include <sgtty.h>
#endif

/* Define _POSIX_VDISABLE if we are not using the `new' tty driver and
   it is not already defined.  It is used both to determine if a
   special character is disabled and to disable certain special
   characters.  Posix systems should set to 0, USG systems to -1. */
#if !defined (NEW_TTY_DRIVER) && !defined (_POSIX_VDISABLE)
#  if defined (_POSIX_VERSION)
#    define _POSIX_VDISABLE 0
#  else /* !_POSIX_VERSION */
#    define _POSIX_VDISABLE -1
#  endif /* !_POSIX_VERSION */
#endif /* !NEW_TTY_DRIVER && !_POSIX_VDISABLE */

#include <errno.h>
extern int errno;

#if defined (SHELL)
#  include <posixstat.h>
#else
#  include <sys/stat.h>
#endif /* !SHELL */
/* #define HACK_TERMCAP_MOTION */

#if defined (USG) && defined (hpux)
#  if !defined (USGr3)
#    define USGr3
#  endif /* USGr3 */
#endif /* USG && hpux */

#if (defined (_POSIX_VERSION) || defined (USGr3)) && !defined(apollo)
#  include <dirent.h>
#  define direct dirent
#  if defined (_POSIX_VERSION)
#    define D_NAMLEN(d) (strlen ((d)->d_name))
#  else /* !_POSIX_VERSION */
#    define D_NAMLEN(d) ((d)->d_reclen)
#  endif /* !_POSIX_VERSION */
#else /* !_POSIX_VERSION && !USGr3 */
#  define D_NAMLEN(d) ((d)->d_namlen)
#  if !defined (USG)
#    include <sys/dir.h>
#  else /* USG */
#    if defined (Xenix)
#      include <sys/ndir.h>
#    else /* !Xenix */
#      include <ndir.h>
#    endif /* !Xenix */
#  endif /* USG */
#endif /* !POSIX_VERSION && !USGr3 */

#if defined (USG) && defined (TIOCGWINSZ)
#  include <sys/stream.h>
#  if defined (USGr4) || defined (USGr3)
#    if defined (Symmetry) || defined (_SEQUENT_)
#      include <sys/pte.h>
#    else
#      include <sys/ptem.h>
#    endif /* !Symmetry || _SEQUENT_ */
#  endif /* USGr4 */
#endif /* USG && TIOCGWINSZ */

#if defined (TERMIOS_TTY_DRIVER)
static struct termios otio;
#else
static struct termio otio;
#endif /* !TERMIOS_TTY_DRIVER */

/* Non-zero means echo characters as they are read. */
int readline_echoing_p = 1;

/* The character that can generate an EOF.  Really read from
   the terminal driver... just defaulted here. */

#ifndef CTRL
#define CTRL(key)	((key)-'@')
#endif

static int eof_char = CTRL ('D');

/* **************************************************************** */
/*								    */
/*		      Saving and Restoring the TTY	    	    */
/*								    */
/* **************************************************************** */

/* Non-zero means that the terminal is in a prepped state. */
static int terminal_prepped = 0;

#if defined (NEW_TTY_DRIVER)

/* Standard flags, including ECHO. */
static int original_tty_flags = 0;

/* Local mode flags, like LPASS8. */
static int local_mode_flags = 0;

/* Terminal characters.  This has C-s and C-q in it. */
static struct tchars original_tchars;

/* Local special characters.  This has the interrupt characters in it. */
#if defined (TIOCGLTC)
static struct ltchars original_ltchars;
#endif

/* Bind KEY to FUNCTION.  Returns non-zero if KEY is out of range. */

#if defined (TIOCGETC)
#if defined (USE_XON_XOFF)

int
bind_key (key, function)
     int key;
     Function *function;
{
  if (key < 0)
    return (key);

  if (key > 127 && key < 256)
    {
      if (keymap[ESC].type == ISKMAP)
	{
	  Keymap escmap = (Keymap)keymap[ESC].function;

	  key -= 128;
	  escmap[key].type = ISFUNC;
	  escmap[key].function = function;
	  return (0);
	}
      return (key);
    }

  keymap[key].type = ISFUNC;
  keymap[key].function = function;
 return (0);
}
#endif
#endif

/* We use this to get and set the tty_flags. */
static struct sgttyb the_ttybuff;

#if defined (USE_XON_XOFF)
/* If the terminal was in xoff state when we got to it, then xon_char
   contains the character that is supposed to start it again. */
static int xon_char, xoff_state;
#endif /* USE_XON_XOFF */

/* **************************************************************** */
/*								    */
/*			Bogus Flow Control      		    */
/*								    */
/* **************************************************************** */

restart_output (count, key)
     int count, key;
{
  int fildes = fileno (stdin);
#if defined (TIOCSTART)
#if defined (apollo)
  ioctl (&fildes, TIOCSTART, 0);
#else
  ioctl (fildes, TIOCSTART, 0);
#endif /* apollo */

#else
#  if defined (TERMIOS_TTY_DRIVER)
        tcflow (fildes, TCOON);
#  else
#    if defined (TCXONC)
        ioctl (fildes, TCXONC, TCOON);
#    endif /* TCXONC */
#  endif /* !TERMIOS_TTY_DRIVER */
#endif /* TIOCSTART */
}

/* Put the terminal in CBREAK mode so that we can detect key presses. */
void prep_terminal ()
{
  int tty = fileno (stdin);
#if defined (HAVE_BSD_SIGNALS)
  int oldmask;
#endif /* HAVE_BSD_SIGNALS */

  if (terminal_prepped)
    return;

  oldmask = sigblock (sigmask (SIGINT));

  /* We always get the latest tty values.  Maybe stty changed them. */
  ioctl (tty, TIOCGETP, &the_ttybuff);
  original_tty_flags = the_ttybuff.sg_flags;

  readline_echoing_p = (original_tty_flags & ECHO);

#if defined (TIOCLGET)
  ioctl (tty, TIOCLGET, &local_mode_flags);
#endif

#if !defined (ANYP)
#  define ANYP (EVENP | ODDP)
#endif

  /* If this terminal doesn't care how the 8th bit is used,
     then we can use it for the meta-key.  We check by seeing
     if BOTH odd and even parity are allowed. */
  if (the_ttybuff.sg_flags & ANYP)
    {
#if defined (PASS8)
      the_ttybuff.sg_flags |= PASS8;
#endif

      /* Hack on local mode flags if we can. */
#if defined (TIOCLGET) && defined (LPASS8)
      {
	int flags;
	flags = local_mode_flags | LPASS8;
	ioctl (tty, TIOCLSET, &flags);
      }
#endif /* TIOCLGET && LPASS8 */
    }

#if defined (TIOCGETC)
  {
    struct tchars temp;

    ioctl (tty, TIOCGETC, &original_tchars);
    temp = original_tchars;

#if defined (USE_XON_XOFF)
    /* Get rid of C-s and C-q.
       We remember the value of startc (C-q) so that if the terminal is in
       xoff state, the user can xon it by pressing that character. */
    xon_char = temp.t_startc;
    temp.t_stopc = -1;
    temp.t_startc = -1;

    /* If there is an XON character, bind it to restart the output. */
    if (xon_char != -1)
      bind_key (xon_char, restart_output);
#endif /* USE_XON_XOFF */

    /* If there is an EOF char, bind eof_char to it. */
    if (temp.t_eofc != -1)
      eof_char = temp.t_eofc;

#if defined (NO_KILL_INTR)
    /* Get rid of C-\ and C-c. */
    temp.t_intrc = temp.t_quitc = -1;
#endif /* NO_KILL_INTR */

    ioctl (tty, TIOCSETC, &temp);
  }
#endif /* TIOCGETC */

#if defined (TIOCGLTC)
  {
    struct ltchars temp;

    ioctl (tty, TIOCGLTC, &original_ltchars);
    temp = original_ltchars;

    /* Make the interrupt keys go away.  Just enough to make people
       happy. */
    temp.t_dsuspc = -1;	/* C-y */
    temp.t_lnextc = -1;	/* C-v */

    ioctl (tty, TIOCSLTC, &temp);
  }
#endif /* TIOCGLTC */

  the_ttybuff.sg_flags &= ~(ECHO | CRMOD);
  the_ttybuff.sg_flags |= CBREAK;
  ioctl (tty, TIOCSETN, &the_ttybuff);

  terminal_prepped = 1;

#if defined (HAVE_BSD_SIGNALS)
  sigsetmask (oldmask);
#endif
}

/* Restore the terminal to its original state. */
void deprep_terminal ()
{
  int tty = fileno (stdin);
#if defined (HAVE_BSD_SIGNALS)
  int oldmask;
#endif

  if (!terminal_prepped)
    return;

  oldmask = sigblock (sigmask (SIGINT));

  the_ttybuff.sg_flags = original_tty_flags;
  ioctl (tty, TIOCSETN, &the_ttybuff);
  readline_echoing_p = 1;

#if defined (TIOCLGET)
  ioctl (tty, TIOCLSET, &local_mode_flags);
#endif

#if defined (TIOCSLTC)
  ioctl (tty, TIOCSLTC, &original_ltchars);
#endif

#if defined (TIOCSETC)
  ioctl (tty, TIOCSETC, &original_tchars);
#endif
  terminal_prepped = 0;

#if defined (HAVE_BSD_SIGNALS)
  sigsetmask (oldmask);
#endif
}

#else  /* !defined (NEW_TTY_DRIVER) */

#if !defined (VMIN)
#define VMIN VEOF
#endif

#if !defined (VTIME)
#define VTIME VEOL
#endif

void prep_terminal ()
{
  int tty = fileno (stdin);
#if defined (TERMIOS_TTY_DRIVER)
  struct termios tio;
#else
  struct termio tio;
#endif /* !TERMIOS_TTY_DRIVER */

#if defined (HAVE_POSIX_SIGNALS)
  sigset_t set, oset;
#else
#  if defined (HAVE_BSD_SIGNALS)
  int oldmask;
#  endif /* HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */

  if (terminal_prepped)
    return;

  /* Try to keep this function from being INTerrupted.  We can do it
     on POSIX and systems with BSD-like signal handling. */
#if defined (HAVE_POSIX_SIGNALS)
  sigemptyset (&set);
  sigemptyset (&oset);
  sigaddset (&set, SIGINT);
  sigprocmask (SIG_BLOCK, &set, &oset);
#else /* !HAVE_POSIX_SIGNALS */
#  if defined (HAVE_BSD_SIGNALS)
  oldmask = sigblock (sigmask (SIGINT));
#  endif /* HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */

#if defined (TERMIOS_TTY_DRIVER)
  tcgetattr (tty, &tio);
#else
  ioctl (tty, TCGETA, &tio);
#endif /* !TERMIOS_TTY_DRIVER */

  otio = tio;

  readline_echoing_p = (tio.c_lflag & ECHO);

  tio.c_lflag &= ~(ICANON | ECHO);

  if (otio.c_cc[VEOF] != _POSIX_VDISABLE)
    eof_char = otio.c_cc[VEOF];

#if defined (USE_XON_XOFF)
#if defined (IXANY)
  tio.c_iflag &= ~(IXON | IXOFF | IXANY);
#else
  /* `strict' Posix systems do not define IXANY. */
  tio.c_iflag &= ~(IXON | IXOFF);
#endif /* IXANY */
#endif /* USE_XON_XOFF */

  /* Only turn this off if we are using all 8 bits. */
  if ((tio.c_cflag & CSIZE) == CS8)
    tio.c_iflag &= ~(ISTRIP | INPCK);

  /* Make sure we differentiate between CR and NL on input. */
  tio.c_iflag &= ~(ICRNL | INLCR);

#if !defined (HANDLE_SIGNALS)
  tio.c_lflag &= ~ISIG;
#else
  tio.c_lflag |= ISIG;
#endif

  tio.c_cc[VMIN] = 1;
  tio.c_cc[VTIME] = 0;

  /* Turn off characters that we need on Posix systems with job control,
     just to be sure.  This includes ^Y and ^V.  This should not really
     be necessary.  */
#if defined (TERMIOS_TTY_DRIVER) && defined (_POSIX_JOB_CONTROL)

#if defined (VLNEXT)
  tio.c_cc[VLNEXT] = _POSIX_VDISABLE;
#endif

#if defined (VDSUSP)
  tio.c_cc[VDSUSP] = _POSIX_VDISABLE;
#endif

#endif /* POSIX && JOB_CONTROL */

#if defined (TERMIOS_TTY_DRIVER)
  tcsetattr (tty, TCSADRAIN, &tio);
  tcflow (tty, TCOON);		/* Simulate a ^Q. */
#else
  ioctl (tty, TCSETAW, &tio);
  ioctl (tty, TCXONC, 1);	/* Simulate a ^Q. */
#endif /* !TERMIOS_TTY_DRIVER */

  terminal_prepped = 1;

#if defined (HAVE_POSIX_SIGNALS)
  sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
#else
#  if defined (HAVE_BSD_SIGNALS)
  sigsetmask (oldmask);
#  endif /* HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */
}

void deprep_terminal ()
{
  int tty = fileno (stdin);

  /* Try to keep this function from being INTerrupted.  We can do it
     on POSIX and systems with BSD-like signal handling. */
#if defined (HAVE_POSIX_SIGNALS)
  sigset_t set, oset;
#else /* !HAVE_POSIX_SIGNALS */
#  if defined (HAVE_BSD_SIGNALS)
  int oldmask;
#  endif /* HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */

  if (!terminal_prepped)
    return;

#if defined (HAVE_POSIX_SIGNALS)
  sigemptyset (&set);
  sigemptyset (&oset);
  sigaddset (&set, SIGINT);
  sigprocmask (SIG_BLOCK, &set, &oset);
#else /* !HAVE_POSIX_SIGNALS */
#  if defined (HAVE_BSD_SIGNALS)
  oldmask = sigblock (sigmask (SIGINT));
#  endif /* HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */

#if defined (TERMIOS_TTY_DRIVER)
  tcsetattr (tty, TCSADRAIN, &otio);
  tcflow (tty, TCOON);		/* Simulate a ^Q. */
#else /* TERMIOS_TTY_DRIVER */
  ioctl (tty, TCSETAW, &otio);
  ioctl (tty, TCXONC, 1);	/* Simulate a ^Q. */
#endif /* !TERMIOS_TTY_DRIVER */

  terminal_prepped = 0;

#if defined (HAVE_POSIX_SIGNALS)
  sigprocmask (SIG_SETMASK, &oset, (sigset_t *)NULL);
#else /* !HAVE_POSIX_SIGNALS */
#  if defined (HAVE_BSD_SIGNALS)
  sigsetmask (oldmask);
#  endif /* HAVE_BSD_SIGNALS */
#endif /* !HAVE_POSIX_SIGNALS */
}
#endif  /* NEW_TTY_DRIVER */

/* If a character is available to be read, then read it
   and stuff it into IBUFFER.  Otherwise, just return. */

long pending = -1L;

long key_avail (stream)
	FILE *stream;
{
  int tty = fileno (stream);
  long chars_avail = pending;
  int result;

  if(!terminal_prepped)  prep_terminal();

#if defined (FIONREAD)
  result = ioctl (tty, FIONREAD, &chars_avail);
#endif

  if(chars_avail == -1L)
    {  unsigned char inchar;

       fcntl(tty, F_SETFL, O_NDELAY);
       result = read(tty, &inchar, sizeof(char));
       if(result == sizeof(char))
       {
         chars_avail = 1;
         pending = (long)inchar;
       }
       else
         chars_avail = 0;
       fcntl(tty, F_SETFL, 0);
    }

  return chars_avail;
}

/* Get a key from the buffer of characters to be read.
   Return the key in KEY.
   Result is KEY if there was a key, or 0 if there wasn't. */

/* When compiling and running in the `Posix' environment, Ultrix does
   not restart system calls, so this needs to do it. */

unsigned char getkey(stream)
     FILE *stream;
{
  int result;
  unsigned char c;

  if(!terminal_prepped)  prep_terminal();

  while (pending < 0)
    {
      result = read (fileno (stream), &c, sizeof (char));

      if (result == sizeof (char))
        return /* (c == 0x7F ? 0x08 :*/ c /*)*/;

      /* If zero characters are returned, then the file that we are
	 reading from is empty!  Return EOF in that case. */
      if (result == 0)
	return CTRL('D');

      /* If the error that we received was SIGINT, then try again,
	 this is simply an interrupted system call to read ().
	 Otherwise, some error ocurred, also signifying EOF. */
      if (errno != EINTR)
	return (EOF);
    }

  result = (int) pending;
  pending = -1L;

  return result;
}

#ifdef TEST

#include <time.h>

int timewait=100000;

int main()
{
	unsigned char c;

	prep_terminal();

	do
	{
		int i=0;

		while(!key_avail(stdin))
		{
			printf("%04d",i);
			fflush(stdout);
			{
				struct timeval timeout;
				timeout.tv_sec=timewait/1000000;
				timeout.tv_usec=timewait%1000000;
				(void)select(0,0,0,0,&timeout);
			}
			i++;
			printf("\b\b\b\b");
			fflush(stdout);
		}
		c = getkey(stdin);
		printf("%02x,",(int)c);
		fflush(stdout);
	}	while(c != 0x1B);

	deprep_terminal();
	puts("");
}
#endif


/* signal handling adapted from pfe by Dirk Zoller (Copylefted) - anton */

static void
graceful_exit (int sig)
{
  deprep_terminal();
  fprintf (stderr, "\n\n%s.\n", strsignal (sig));
  exit (0x80|sig);
}

jmp_buf throw_jmp_buf;

static void 
signal_throw(int sig)
{
  int code;
  struct {
    int signal;
    int throwcode;
  } *p, throwtable[] = {
    { SIGINT, -28 },
    { SIGFPE, -55 },
    { SIGBUS, -23 },
    { SIGSEGV, -9 },
  };
  signal(sig,signal_throw);
  for (code=-256-sig, p=throwtable; p<throwtable+(sizeof(throwtable)/sizeof(*p)); p++)
    if (sig == p->signal) {
      code = p->throwcode;
      break;
    }
  longjmp(throw_jmp_buf,code); /* or use siglongjmp ? */
}

static void
termprep (int sig)
{
  terminal_prepped=0;
  signal(sig,termprep);
}

void
install_signal_handlers (void)
{

#if 0
/* these signals are handled right by default, no need to handle them;
   they are listed here just for fun */
  static short sigs_to_default [] = {
#ifdef SIGCHLD
    SIGCHLD,
#endif
#ifdef SIGINFO
    SIGINFO,
#endif
#ifdef SIGIO
    SIGIO,
#endif
#ifdef SIGLOST
    SIGLOST,
#endif
#ifdef SIGKILL
    SIGKILL,
#endif
#ifdef SIGSTOP
    SIGSTOP,
#endif
#ifdef SIGPWR
    SIGPWR,
#endif
#ifdef SIGMSG
    SIGMSG,
#endif
#ifdef SIGDANGER
    SIGDANGER,
#endif
#ifdef SIGMIGRATE
    SIGMIGRATE,
#endif
#ifdef SIGPRE
    SIGPRE,
#endif
#ifdef SIGVIRT
    SIGVIRT,
#endif
#ifdef SIGGRANT
    SIGGRANT,
#endif
#ifdef SIGRETRACT
    SIGRETRACT,
#endif
#ifdef SIGSOUND
    SIGSOUND,
#endif
#ifdef SIGSAK
    SIGSAK,
#endif
#ifdef SIGTSTP
    SIGTSTP,
#endif
#ifdef SIGTTIN
    SIGTTIN,
#endif
#ifdef SIGTTOU
    SIGTTOU,
#endif
#ifdef SIGWINCH
    SIGWINCH,
#endif
#ifdef SIGSTKFLT
    SIGSTKFLT,
#endif
#ifdef SIGUNUSED
    SIGUNUSED,
#endif
  };
#endif

  static short sigs_to_throw [] = {
#ifdef SIGBREAK
    SIGBREAK,
#endif
#ifdef SIGINT
    SIGINT,
#endif
#ifdef SIGILL
    SIGILL,
#endif
#ifdef SIGEMT
    SIGEMT,
#endif
#ifdef SIGFPE
    SIGFPE,
#endif
#ifdef SIGIOT
    SIGIOT,
#endif
#ifdef SIGSEGV
    SIGSEGV,
#endif
#ifdef SIGALRM
    SIGALRM,
#endif
#ifdef SIGPOLL
    SIGPOLL,
#endif
#ifdef SIGPROF
    SIGPROF,
#endif
#ifdef SIGBUS
    SIGBUS,
#endif
#ifdef SIGSYS
    SIGSYS,
#endif
#ifdef SIGTRAP
    SIGTRAP,
#endif
#ifdef SIGURG
    SIGURG,
#endif
#ifdef SIGUSR1
    SIGUSR1,
#endif
#ifdef SIGUSR2
    SIGUSR2,
#endif
#ifdef SIGVTALRM
    SIGVTALRM,
#endif
#ifdef SIGXFSZ
    SIGXFSZ,
#endif
  };
  static short sigs_to_quit [] = {
#ifdef SIGHUP
    SIGHUP,
#endif
#ifdef SIGQUIT
    SIGQUIT,
#endif
#ifdef SIGABRT
    SIGABRT,
#endif
#ifdef SIGPIPE
    SIGPIPE,
#endif
#ifdef SIGTERM
    SIGTERM,
#endif
#ifdef SIGXCPU
    SIGXCPU,
#endif
  };
  static short sigs_to_termprep [] = {
#ifdef SIGCONT
    SIGCONT,
#endif
  };
  int i;

#define DIM(X)		(sizeof (X) / sizeof *(X))
/*
  for (i = 0; i < DIM (sigs_to_ignore); i++)
    signal (sigs_to_ignore [i], SIG_IGN);
*/
  for (i = 0; i < DIM (sigs_to_throw); i++)
    signal (sigs_to_throw [i], signal_throw);
  for (i = 0; i < DIM (sigs_to_quit); i++)
    signal (sigs_to_quit [i], graceful_exit);
  for (i = 0; i < DIM (sigs_to_termprep); i++)
    signal (sigs_to_termprep [i], termprep);
}
/* end signal handling */