/* systty.h - System-dependent definitions for terminals.
   Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc.

This file is part of XEmacs.

XEmacs is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs.  If not, see <http://www.gnu.org/licenses/>. */

/* Synched up with: FSF 19.30. */

#ifndef INCLUDED_systty_h_
#define INCLUDED_systty_h_

#ifdef HAVE_TERMIOS
# define HAVE_TCATTR
#endif


/* Include the proper files.  */

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

/* XEmacs: TERMIOS is mo' better than TERMIO so we use it if it's
   there.  Since TERMIO is backward-compatibility stuff if both it
   and TERMIOS exist, it's more likely to be broken. */

#if defined (HAVE_TERMIOS)

/*****     (1) The TERMIOS way (POSIX style)     *****/

# if defined (_AIX) && defined (_I386)
#  include <termios.h>		/* termios.h needs to be before termio.h */
#  include <termio.h>
# else
#  if !defined (NO_TERMIO)
#   include <termio.h>
#  endif
#  include <termios.h>
# endif /* _AIX && _I386 */
# ifndef INCLUDED_FCNTL
#  define INCLUDED_FCNTL
#  include <fcntl.h>
# endif

#elif defined (HAVE_TERMIO)

/*****    (2) The TERMIO way (system V style)    *****/

# ifndef NO_TERMIO
#  include <termio.h>
# endif /* not NO_TERMIO */
# ifndef INCLUDED_FCNTL
#  define INCLUDED_FCNTL
#  include <fcntl.h>
# endif

#elif defined (WIN32_NATIVE)

/*****             (3) The WIN32_NATIVE way              *****/

/* Nothing doing */

#else

/*****              (4) The BSD way              *****/

# ifdef linux /* XEmacs addition -- necessary? */
#  include <bsd/sgtty.h>
# else
#  include <sgtty.h>
# endif


#endif /* HAVE_TERMIOS */

/* XEmacs: I don't think we need the following crap. */
#ifdef __GNU_LIBRARY__
#include <termios.h>
#endif

/* Formerly there was a conditional that included sys/filio.h if
   USG5_4 was defined, but this is already included in s/usg5-4.h */

/* Generally useful to include this file: */

#if !defined (WIN32_NATIVE)
# include <sys/ioctl.h>
#endif


/* ----------------------------------------------------- */
/*                 miscellaneous includes                */
/* ----------------------------------------------------- */

/* Include files for PTY's */

#if defined (HAVE_SYS_PTYIO_H) /* HP-UX */
#include <sys/ptyio.h>
#endif

#if defined (HAVE_PTY_H)
#include <pty.h>
#elif defined (HAVE_SYS_PTY_H)
#include <sys/pty.h>
#endif


/* ----------------------------------------------------- */
/*           inhibiting particular features              */
/* ----------------------------------------------------- */


#if defined (BROKEN_TIOCGETC)
#undef TIOCGETC  /* Avoid confusing some conditionals that test this.  */
#endif

/* XEmacs: SIGIO is cleaned up so we remove the crap here that messes
   with it (and FIONREAD and FASYNC, which are related). */

/* On TERMIOS systems, the tcmumbleattr calls take care of these
   parameters, and it's a bad idea to use them (on AIX, it makes the
   tty hang for a long time).  */
#if defined (TIOCGLTC) && !defined (HAVE_TERMIOS)
#define HAVE_LTCHARS
#endif

#if defined (TIOCGETC) && !defined (HAVE_TERMIOS)
#define HAVE_TCHARS
#endif


/* ----------------------------------------------------- */
/*             disabling terminal functions              */
/* ----------------------------------------------------- */

/* Try to establish the correct character to disable terminal functions
   in a system-independent manner.
   We use the POSIX standard way to do this, and emulate on other systems. */

#ifndef _POSIX_VDISABLE
# if defined CDEL
#  define _POSIX_VDISABLE CDEL
# else
#  define _POSIX_VDISABLE 255
# endif
#endif /* ! _POSIX_VDISABLE */


/* ----------------------------------------------------- */
/*    Get the number of characters queued for output     */
/* ----------------------------------------------------- */

/* EMACS_OUTQSIZE(FD, int *SIZE) stores the number of characters
   queued for output to the terminal FD in *SIZE, if FD is a tty.
   Returns -1 if there was an error (i.e. FD is not a tty), 0
   otherwise.  */
#ifdef TIOCOUTQ
#define EMACS_OUTQSIZE(fd, size) ioctl (fd, TIOCOUTQ, size)
#endif

#ifdef HAVE_TERMIO
#ifdef TCOUTQ
#undef EMACS_OUTQSIZE
#define EMACS_OUTQSIZE(fd, size) ioctl (fd, TCOUTQ, size)
#endif
#endif


/* -------------------------------------------------------------------- */
/*       Manipulate a terminal's current (foreground) process group     */
/* -------------------------------------------------------------------- */

/* EMACS_GET_TTY_PGRP(int FD, pid_t *PGID) sets *PGID to the terminal
   FD's current foreground process group.  Return -1 if there is an error.

   EMACS_SET_TTY_PGRP(int FD, pid_t *PGID) sets the terminal FD's current
   foreground process group to *PGID.  Return -1 if there is an error.

   We prefer using the ioctl (BSD) interface instead of its Posix
   replacement tgetpgrp/tcsetpgrp since that is documented as being
   restricted to processes sharing the same controlling tty. */

#if defined (TIOCGPGRP)

#define EMACS_GET_TTY_PROCESS_GROUP(fd, pgid) ioctl (fd, TIOCGPGRP, pgid)
#define EMACS_SET_TTY_PROCESS_GROUP(fd, pgid) ioctl (fd, TIOCSPGRP, pgid)

#elif defined (HAVE_TCGETPGRP)

#define EMACS_GET_TTY_PROCESS_GROUP(fd, pgid) (*(pgid) = tcgetpgrp (fd))
#define EMACS_SET_TTY_PROCESS_GROUP(fd, pgid) tcsetpgrp (fd, *(pgid))

#else

/* Just ignore this for now and hope for the best */
#define EMACS_GET_TTY_PROCESS_GROUP(fd, pgid) 0
#define EMACS_SET_TTY_PROCESS_GROUP(fd, pgif) 0

#endif

/* EMACS_GETPGRP (arg) returns the process group of the terminal.  */

#ifdef GETPGRP_VOID
#define EMACS_GETPGRP(x) getpgrp()
#else
#define EMACS_GETPGRP(x) getpgrp(x)
#endif /* GETPGRP_VOID */

/* XEmacs backward-compatibility.  Is 0 always a reasonable argument? */
#define EMACS_GET_PROCESS_GROUP() EMACS_GETPGRP (0)

/* XEmacs addition? */

/* EMACS_SEPARATE_PROCESS_GROUP () creates a separate process group for the
   running process. */

/* EMACS_SET_PROCESS_GROUP () sets our process group as specified. */

/* POSIX calls for setpgid(), so we use it if it's available.
   Otherwise use setpgrp(), in USG or BSD flavor.  Note that
   on newer systems, setpgrp() has unwanted effects (e.g.
   creating a new session), so we want to avoid its use
   if possible.

   NOTE: On some older systems, we should consider using setpgrp2()
   if it exists.  This is sufficiently rare, though, that there
   seems no point in autodetecting it.  Currently dgux.h is the
   only place where this has to be munged. */

#if defined (HAVE_SETPGID)
#  define EMACS_SEPARATE_PROCESS_GROUP() setpgid (0, 0)
#  define EMACS_SET_PROCESS_GROUP(pg) setpgid (0, pg)
#elif defined (USG)
#  define EMACS_SEPARATE_PROCESS_GROUP() setpgrp ()
/* old (pre-SVR4) USG's don't provide any way to do this.
   No big loss -- it just means that ^Z won't work right
   if we're run from sh. */
#  define EMACS_SET_PROCESS_GROUP(pg)
#elif defined (WIN32_NATIVE)
#  define EMACS_SEPARATE_PROCESS_GROUP()
#else
/* Under NeXTstep, a process group of 0 is not the same as specifying
   your own process ID, so we go ahead and specify it explicitly. */
#  define EMACS_SEPARATE_PROCESS_GROUP() setpgrp (0, getpid ())
#  define EMACS_SET_PROCESS_GROUP(pg) setpgrp (0, pg)
#endif


/* --------------------------------------------------------- */
/*   Manipulate a TTY's input/output processing parameters   */
/* --------------------------------------------------------- */

/* struct emacs_tty is a structure used to hold the current tty
   parameters.  If the terminal has several structures describing its
   state, for example a struct tchars, a struct sgttyb, a struct
   tchars, a struct ltchars, and a struct pagechars, struct
   emacs_tty should contain an element for each parameter struct
   that Emacs may change.

   emacs_get_tty (int FD, struct emacs_tty *P) stores the parameters
   of the tty on FD in *P.  Return zero if all's well, or -1 if we ran
   into an error we couldn't deal with.

   emacs_set_tty (int FD, struct emacs_tty *P, int flushp)
   sets the parameters of the tty on FD according to the contents of
   *P.  If flushp is non-zero, we discard queued input to be
   written before making the change.
   Return 0 if all went well, and -1 if anything failed.

   EMACS_TTY_TABS_OK (struct emacs_tty *P) is false iff the kernel
   expands tabs to spaces upon output; in that case, there is no
   advantage to using tabs over spaces.  */


/* For each tty parameter structure that Emacs might want to save and restore,
   - include an element for it in this structure, and
   - extend the emacs_{get,set}_tty functions in sysdep.c to deal with the
     new members.  */

struct emacs_tty {

/* There is always one of the following elements, so there is no need
   for dummy get and set definitions.  */
#ifdef HAVE_TCATTR
  struct termios main;
#else /* !HAVE_TCATTR */
#ifdef HAVE_TERMIO
  struct termio main;
#else /* !HAVE_TERMIO */
#ifdef WIN32_NATIVE
  int main;
#else  /* not WIN32_NATIVE */
  struct sgttyb main;
#endif /* not WIN32_NATIVE */
#endif /* !HAVE_TERMIO */
#endif /* !HAVE_TCATTR */

/* If we have TERMIOS, we don't need to do this - they're taken care of
   by the tc*attr calls.  */
#ifndef HAVE_TERMIOS
#ifdef HAVE_LTCHARS
  struct ltchars ltchars;
#endif /* HAVE_LTCHARS */

#ifdef HAVE_TCHARS
  struct tchars tchars;
  int lmode;
#endif /* HAVE_TCHARS */
#endif /* HAVE_TERMIOS */
};

int emacs_get_tty (int fd, struct emacs_tty *settings);
int emacs_set_tty (int fd, struct emacs_tty *settings, int flushp);


/* --------------------------------------------------------- */
/*                Define EMACS_TTY_TABS_OK                   */
/* --------------------------------------------------------- */

#if defined (TABDLY) && defined (TAB3)
#  define EMACS_TTY_TABS_OK(p) (((p)->main.c_oflag & TABDLY) != TAB3)
#elif defined (OXTABS)
#  define EMACS_TTY_TABS_OK(p) (((p)->main.c_oflag & OXTABS) != OXTABS)
#else
#  define EMACS_TTY_TABS_OK(p) 1
#endif

#endif /* INCLUDED_systty_h_ */
