Fix compilation when MULE is disabled, due to a missing ifdef.

[sxemacs] / src / sysdep.c

/* Interfaces to system-dependent kernel and library entries.
   Copyright (C) 1985-1988, 1992-1995 Free Software Foundation, Inc.
   Copyright (C) 1995 Tinker Systems.
   Copyright (C) 2007 Sebastian Freundt

This file is part of SXEmacs

SXEmacs 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.

SXEmacs 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 this program.  If not, see <http://www.gnu.org/licenses/>. */


/* Synched up with: FSF 19.30 except for some Windows-NT crap. */

/* Substantially cleaned up by Ben Wing, Dec. 1994 / Jan. 1995. */

/* In this file, open, read and write refer to the system calls,
   not our sugared interfaces sys_open, sys_read and sys_write.
 */

#define DONT_ENCAPSULATE

#include <config.h>

#include "lisp.h"

/* ------------------------------- */
/*          basic includes         */
/* ------------------------------- */

#ifdef HAVE_TTY
#include "ui/TTY/console-tty.h" /* for stuff in stuff_char and
                                   others. Seriously in need of
                                   refactoring... */
#else
#include "syssignal.h"
#include "ui/systty.h"
#endif                          /* HAVE_TTY */

#include "ui/console-stream.h"

#include "buffer.h"
#include "events/events.h"
#include "ui/frame.h"
#include "ui/redisplay.h"
#include "process.h"
#include "sysdep.h"
#include "ui/window.h"

#include <setjmp.h>
#ifdef HAVE_LIBGEN_H            /* Must come before sysfile.h */
#include <libgen.h>
#endif
#include "sysfile.h"
#include "syswait.h"
#include "sysdir.h"
#include "systime.h"

#include "sysproc.h"

#include <sys/times.h>

/* ------------------------------- */
/*         TTY definitions         */
/* ------------------------------- */

#ifdef USG
#include <sys/utsname.h>
#if defined (TIOCGWINSZ) || defined (ISC4_0)
#ifdef NEED_SIOCTL
#include <sys/sioctl.h>
#endif
#ifdef NEED_PTEM_H
#include <sys/stream.h>
#include <sys/ptem.h>
#endif
#endif                          /* TIOCGWINSZ or ISC4_0 */
#endif                          /* USG */

/* LPASS8 is new in 4.3, and makes cbreak mode provide all 8 bits.  */
#ifndef LPASS8
#define LPASS8 0
#endif

#ifndef HAVE_H_ERRNO
int h_errno;
#endif

#ifdef HAVE_TTY

static int baud_convert[] =
#ifdef BAUD_CONVERT
    BAUD_CONVERT;
#else
{
        0, 50, 75, 110, 135, 150, 200, 300, 600, 1200,
        1800, 2400, 4800, 9600, 19200, 38400
};
#endif

#endif

#ifdef AIXHFT
static void hft_init(struct console *c);
static void hft_reset(struct console *c);
#include <sys/termio.h>
#endif
\f
/************************************************************************/
/*                         subprocess control                           */
/************************************************************************/

#ifdef HAVE_TTY

#ifdef SIGTSTP

/* Arrange for character C to be read as the next input from
   the terminal.  */
void stuff_char(struct console *con, int c)
{
        int input_fd;

        assert(CONSOLE_TTY_P(con));
        input_fd = CONSOLE_TTY_DATA(con)->infd;
/* Should perhaps error if in batch mode */
#ifdef TIOCSTI
        ioctl(input_fd, TIOCSTI, &c);
#else                           /* no TIOCSTI */
        error
            ("Cannot stuff terminal input characters in this version of Unix.");
#endif                          /* no TIOCSTI */
}

#endif                          /* SIGTSTP */

#endif                          /* HAVE_TTY */

void set_exclusive_use(int fd)
{
#ifdef FIOCLEX
        ioctl(fd, FIOCLEX, 0);
#endif
        /* Ok to do nothing if this feature does not exist */
}

void set_descriptor_non_blocking(int fd)
{
/* Stride people say it's a mystery why this is needed
   as well as the O_NDELAY, but that it fails without this.  */
        /* For AIX: Apparently need this for non-blocking reads on sockets.
           It seems that O_NONBLOCK applies only to FIFOs?  From
           lowry@watson.ibm.com (Andy Lowry). */
        /* #### Should this be conditionalized on FIONBIO? */
#if defined (STRIDE) || (defined (pfa) && defined (HAVE_PTYS)) || defined (AIX)
        {
                int one = 1;
                ioctl(fd, FIONBIO, &one);
        }
#endif

#ifdef F_SETFL
        fcntl(fd, F_SETFL, O_NONBLOCK);
#endif
}

#if defined (NO_SUBPROCESSES)

#ifdef BSD
void wait_without_blocking(void)
{
        wait3(0, WNOHANG | WUNTRACED, 0);
        synch_process_alive = 0;
}
#endif                          /* BSD */

#endif                          /* NO_SUBPROCESSES */

void wait_for_termination(int pid)
{
        /* #### With the new improved SIGCHLD handling stuff, there is much
           less danger of race conditions and some of the comments below
           don't apply.  This should be updated. */

#if defined (NO_SUBPROCESSES)
        while (1) {
                /* No need to be tricky like below; we can just call wait(). */
                /* #### should figure out how to write a wait_allowing_quit().
                   Since hardly any systems don't have subprocess support,
                   however, there doesn't seem to be much point. */
                if (wait(0) == pid)
                        return;
        }
#elif defined (HAVE_WAITPID)
        /* Note that, whenever any subprocess terminates (asynch. or synch.),
           the SIGCHLD handler will be called and it will call wait().  Thus
           we cannot just call wait() ourselves, and we can't block SIGCHLD
           and then call wait(), because then if an asynch.  process dies
           while we're waiting for our synch. process, Emacs will never
           notice that the asynch. process died.

           So, the general approach we take is to repeatedly block until a
           signal arrives, and then check if our process died using kill
           (pid, 0).  (We could also check the value of `synch_process_alive',
           since the SIGCHLD handler will reset that and we know that we're
           only being called on synchronous processes, but this approach is
           safer.  I don't trust the proper delivery of SIGCHLD.

           Note also that we cannot use any form of waitpid().  A loop with
           WNOHANG will chew up CPU time; better to use sleep().  A loop
           without WNOWAIT will screw up the SIGCHLD handler (actually this
           is not true, if you duplicate the exit-status-reaping code; see
           below).  A loop with WNOWAIT will result in a race condition if
           the process terminates between the process-status check and the
           call to waitpid(). */

        /* Formerly, immediate_quit was set around this function call, but
           that could lead to problems if the QUIT happened when SIGCHLD was
           blocked -- it would remain blocked.  Yet another reason why
           immediate_quit is a bad idea.  In any case, there is no reason to
           resort to this because either the SIGIO or the SIGALRM will stop
           the block in EMACS_WAIT_FOR_SIGNAL(). */

        /* Apparently there are bugs on some systems with the second method
           used below (the EMACS_BLOCK_SIGNAL method), whereby zombie
           processes get left around.  It appears in those cases that the
           SIGCHLD handler is never getting invoked.  It's not clear whether
           this is an Emacs bug or a kernel bug or both: on HPUX this
           problem is observed only with XEmacs, but under Solaris 2.4 all
           sorts of different programs have problems with zombies.  The
           method we use here does not require a working SIGCHLD (but will
           not break if it is working), and should be safe. */
        /*
           We use waitpid(), contrary to the remarks above.  There is no
           race condition, because the three situations when sigchld_handler
           is invoked should be handled OK:

           - handler invoked before waitpid(): In this case, subprocess
           status will be set by sigchld_handler.  waitpid() here will
           return -1 with errno set to ECHILD, which is a valid exit
           condition.

           - handler invoked during waitpid(): as above, except that errno
           here will be set to EINTR.  This will cause waitpid() to be
           called again, and this time it will exit with ECHILD.

           - handler invoked after waitpid(): The following code will reap
           the subprocess. In the handler, wait() will return -1 because
           there is no child to reap, and the handler will exit without
           modifying child subprocess status.  */
        int ret, status;

        /* Because the SIGCHLD handler can potentially reap the synchronous
           subprocess, we should take care of that.  */

        /* Will stay in the do loop as long as:
           1. Process is alive
           2. Ctrl-G is not pressed */
        do {
                QUIT;
                ret = waitpid(pid, &status, 0);
                /* waitpid returns 0 if the process is still alive. */
        }
        while (ret == 0 || (ret == -1 && errno == EINTR));

        if (ret == pid)
        {                       /* Success */
                /* Set synch process globals.  This is can also happen
                   in sigchld_handler, and that code is duplicated. */
                synch_process_alive = 0;
                if (WIFEXITED(status))
                        synch_process_retcode = WEXITSTATUS(status);
                else if (WIFSIGNALED(status))
                        synch_process_death = signal_name(WTERMSIG(status));
        }
        /* On exiting the loop, ret will be -1, with errno set to ECHILD if
           the child has already been reaped, e.g. in the signal handler.  */

        /* Otherwise, we've had some error condition here.
           Per POSIX, the only other possibilities are:
           - EFAULT (bus error accessing arg 2) or
           - EINVAL (incorrect arguments),
           which are both program bugs.

           Since implementations may add their own error indicators on top,
           we ignore it by default.  */
#elif defined (EMACS_BLOCK_SIGNAL) && !defined (BROKEN_WAIT_FOR_SIGNAL) && defined (SIGCHLD)
        while (1) {
                static int wait_debugging = 0;  /* Set nonzero to make following
                                                   function work under dbx (at least for bsd).  */
                QUIT;
                if (wait_debugging)
                        return;

                EMACS_BLOCK_SIGNAL(SIGCHLD);
                /* Block SIGCHLD from happening during this check,
                   to avoid race conditions. */
                if (kill(pid, 0) < 0) {
                        EMACS_UNBLOCK_SIGNAL(SIGCHLD);
                        return;
                } else
                        /* WARNING: Whatever this macro does *must* not allow SIGCHLD
                           to happen between the time that it's reenabled and when we
                           begin to block.  Otherwise we may end up blocking for a
                           signal that has already arrived and isn't coming again.
                           Can you say "race condition"?

                           I assume that the system calls sigpause() or sigsuspend()
                           to provide this atomicness.  If you're getting hangs in
                           sigpause()/sigsuspend(), then your OS doesn't implement
                           this properly (this applies under hpux9, for example).
                           Try defining BROKEN_WAIT_FOR_SIGNAL. */
                        EMACS_WAIT_FOR_SIGNAL(SIGCHLD);
        }
#else                           /* not HAVE_WAITPID and (not EMACS_BLOCK_SIGNAL or BROKEN_WAIT_FOR_SIGNAL) */
        /* This approach is kind of cheesy but is guaranteed(?!) to work
           for all systems. */
        while (1) {
                QUIT;
                if (kill(pid, 0) < 0)
                        return;
                emacs_sleep(1);
        }
#endif                          /* OS features */
}

#if !defined (NO_SUBPROCESSES)

/*
 *      flush any pending output
 *      (may flush input as well; it does not matter the way we use it)
 */

void flush_pending_output(int channel)
{
#ifdef HAVE_TERMIOS
        /* If we try this, we get hit with SIGTTIN, because
           the child's tty belongs to the child's pgrp. */
#elif defined (TCFLSH)
        ioctl(channel, TCFLSH, 1);
#elif defined (TIOCFLUSH)
        int zero = 0;
        /* 3rd arg should be ignored
           but some 4.2 kernels actually want the address of an int
           and nonzero means something different.  */
        ioctl(channel, TIOCFLUSH, &zero);
#endif
}

/*  Set up the terminal at the other end of a pseudo-terminal that
    we will be controlling an inferior through.
    It should not echo or do line-editing, since that is done
    in Emacs.  No padding needed for insertion into an Emacs buffer.  */

void child_setup_tty(int out)
{
        struct emacs_tty s;
        emacs_get_tty(out, &s);

#if defined (HAVE_TERMIO) || defined (HAVE_TERMIOS)
        assert(isatty(out));
        s.main.c_oflag |= OPOST;        /* Enable output postprocessing */
        s.main.c_oflag &= ~ONLCR;       /* Disable map of NL to CR-NL on output */
#ifdef NLDLY
        s.main.c_oflag &= ~(NLDLY | CRDLY | TABDLY | BSDLY | VTDLY | FFDLY);
        /* No output delays */
#endif
        s.main.c_lflag &= ~ECHO;        /* Disable echo */
        s.main.c_lflag |= ISIG; /* Enable signals */
#ifdef IUCLC
        s.main.c_iflag &= ~IUCLC;       /* Disable downcasing on input.  */
#endif
#ifdef OLCUC
        s.main.c_oflag &= ~OLCUC;       /* Disable upcasing on output.  */
#endif
        s.main.c_oflag &= ~TAB3;        /* Disable tab expansion */
#if defined (CSIZE) && defined (CS8)
        s.main.c_cflag = (s.main.c_cflag & ~CSIZE) | CS8;       /* Don't strip 8th bit */
#endif
#ifdef ISTRIP
        s.main.c_iflag &= ~ISTRIP;      /* Don't strip 8th bit on input */
#endif
#if 0
        /* Unnecessary as long as ICANON is set */
        s.main.c_cc[VMIN] = 1;  /* minimum number of characters to accept  */
        s.main.c_cc[VTIME] = 0; /* wait forever for at least 1 character  */
#endif                          /* 0 */

        s.main.c_lflag |= ICANON;       /* Enable erase/kill and eof processing */
        s.main.c_cc[VEOF] = 04; /* ensure that EOF is Control-D */
        s.main.c_cc[VERASE] = _POSIX_VDISABLE;  /* disable erase processing */
        s.main.c_cc[VKILL] = _POSIX_VDISABLE;   /* disable kill processing */

#ifdef HPUX
        s.main.c_cflag = (s.main.c_cflag & ~CBAUD) | B9600;     /* baud rate sanity */
#endif                          /* HPUX */

#ifdef AIX
#ifndef IBMR2AIX
        /* AIX enhanced edit loses NULs, so disable it. */
        s.main.c_line = 0;
        s.main.c_iflag &= ~ASCEDIT;
#endif                          /* IBMR2AIX */
        /* Also, PTY overloads NUL and BREAK.
           don't ignore break, but don't signal either, so it looks like NUL.
           This really serves a purpose only if running in an XTERM window
           or via TELNET or the like, but does no harm elsewhere.  */
        s.main.c_iflag &= ~IGNBRK;
        s.main.c_iflag &= ~BRKINT;
#endif                          /* AIX */
#ifdef SIGNALS_VIA_CHARACTERS
        /* TTY `special characters' are used in process_send_signal
           so set them here to something useful.  */
        s.main.c_cc[VQUIT] = '\\' & 037;        /* Control-\ */
        s.main.c_cc[VINTR] = 'C' & 037; /* Control-C */
        s.main.c_cc[VSUSP] = 'Z' & 037; /* Control-Z */
#else                           /* no TIOCGPGRP or no TIOCGLTC or no TIOCGETC */
        /* TTY `special characters' work better as signals, so disable
           character forms */
        s.main.c_cc[VQUIT] = _POSIX_VDISABLE;
        s.main.c_cc[VINTR] = _POSIX_VDISABLE;
        s.main.c_cc[VSUSP] = _POSIX_VDISABLE;
        s.main.c_lflag &= ~ISIG;
#endif                          /* no TIOCGPGRP or no TIOCGLTC or no TIOCGETC */
        s.main.c_cc[VEOL] = _POSIX_VDISABLE;
#if defined (CBAUD)
        /* <mdiers> #### This is not portable. ###
           POSIX does not specify CBAUD, and 4.4BSD does not have it.
           Instead, POSIX suggests to use cfset{i,o}speed().
           [cf. D. Lewine, POSIX Programmer's Guide, Chapter 8: Terminal
           I/O, O'Reilly 1991] */
        s.main.c_cflag = (s.main.c_cflag & ~CBAUD) | B9600;     /* baud rate sanity */
#else
        /* <mdiers> What to do upon failure? Just ignoring rc is probably
           not acceptable, is it? */
        if (cfsetispeed(&s.main, B9600) == -1)  /* ignore */
                ;
        if (cfsetospeed(&s.main, B9600) == -1)  /* ignore */
                ;
#endif                          /* defined (CBAUD) */

#else                           /* not HAVE_TERMIO */

        s.main.sg_flags &= ~(ECHO | CRMOD | ANYP | ALLDELAY | RAW | LCASE
                             | CBREAK | TANDEM);
        s.main.sg_flags |= LPASS8;
        s.main.sg_erase = 0377;
        s.main.sg_kill = 0377;
        s.lmode = LLITOUT | s.lmode;    /* Don't strip 8th bit */

#endif                          /* not HAVE_TERMIO */
        emacs_set_tty(out, &s, 0);

#ifdef RTU
        {
                int zero = 0;
                ioctl(out, FIOASYNC, &zero);
        }
#endif                          /* RTU */
}
#endif                          /* not NO_SUBPROCESSES */
\f
#if !defined (SIGTSTP) && !defined (USG_JOBCTRL)

#if defined(__STDC__) || defined(_MSC_VER)
#define SIG_PARAM_TYPE int
#else
#define SIG_PARAM_TYPE
#endif

/* Record a signal code and the handler for it.  */
struct save_signal {
        int code;
         SIGTYPE(*handler) (SIG_PARAM_TYPE);
};

static void save_signal_handlers(struct save_signal *saved_handlers)
{
        while (saved_handlers->code) {
                saved_handlers->handler
                    =
                    (SIGTYPE(*)(SIG_PARAM_TYPE)) signal(saved_handlers->code,
                                                        SIG_IGN);
                saved_handlers++;
        }
}

static void restore_signal_handlers(struct save_signal *saved_handlers)
{
        while (saved_handlers->code) {
                signal(saved_handlers->code, saved_handlers->handler);
                saved_handlers++;
        }
}

/* Fork a subshell.  */
static void sys_subshell(void)
{
        int pid;
        struct save_signal saved_handlers[5];
        Lisp_Object dir;
        unsigned char *str = 0;
        int len;
        struct gcpro gcpro1;

        saved_handlers[0].code = SIGINT;
        saved_handlers[1].code = SIGQUIT;
        saved_handlers[2].code = SIGTERM;
#ifdef SIGIO
        saved_handlers[3].code = SIGIO;
        saved_handlers[4].code = 0;
#else
        saved_handlers[3].code = 0;
#endif

        /* Mentioning current_buffer->buffer would mean including buffer.h,
           which somehow wedges the hp compiler.  So instead...  */

        if (NILP(Fboundp(Qdefault_directory)))
                goto xyzzy;
        dir = Fsymbol_value(Qdefault_directory);
        if (!STRINGP(dir))
                goto xyzzy;

        GCPRO1(dir);
        dir = Funhandled_file_name_directory(dir);
        dir = expand_and_dir_to_file(dir, Qnil);
        UNGCPRO;
        str = (unsigned char *)alloca(XSTRING_LENGTH(dir) + 2);
        len = XSTRING_LENGTH(dir);
        memcpy(str, XSTRING_DATA(dir), len);
        if (!IS_ANY_SEP(str[len - 1]))
                str[len++] = DIRECTORY_SEP;
        str[len] = 0;
      xyzzy:

        pid = fork();

        if (pid == -1)
                error("Can't spawn subshell");
        if (pid == 0)
        {
                char *sh = 0;

                if (sh == 0)
                        sh = (char *)egetenv("SHELL");
                if (sh == 0)
                        sh = "sh";

                /* Use our buffer's default directory for the subshell.  */
                if (str)
                        sys_chdir(str);

#if !defined (NO_SUBPROCESSES)
                close_process_descs();  /* Close Emacs's pipes/ptys */
#endif

#ifdef SET_EMACS_PRIORITY
                if (emacs_priority != 0)
                        nice(-emacs_priority);  /* Give the new shell the default priority */
#endif

                execlp(sh, sh, 0);
                write(1, "Can't execute subshell", 22);
                _exit(1);
        }

        save_signal_handlers(saved_handlers);
        synch_process_alive = 1;
        wait_for_termination(pid);
        restore_signal_handlers(saved_handlers);
}
#endif                          /* !defined (SIGTSTP) && !defined (USG_JOBCTRL) */
\f
/* Suspend the Emacs process; give terminal to its superior.  */
void sys_suspend(void)
{
#if defined (SIGTSTP)
        {
                int pgrp = EMACS_GET_PROCESS_GROUP();
                EMACS_KILLPG(pgrp, SIGTSTP);
        }

#elif defined (USG_JOBCTRL)
        /* If you don't know what this is don't mess with it */
        ptrace(0, 0, 0, 0);     /* set for ptrace - caught by csh */
        kill(getpid(), SIGQUIT);

#else                           /* No SIGTSTP or USG_JOBCTRL */

        /* On a system where suspending is not implemented,
           instead fork a subshell and let it talk directly to the terminal
           while we wait.  */
        sys_subshell();

#endif
}

/* Suspend a process if possible; give terminal to its superior.  */
void sys_suspend_process(int process)
{
        /* I don't doubt that it is possible to suspend processes on
         * VMS machines or thost that use USG_JOBCTRL,
         * but I don't know how to do it, so...
         */
#if defined (SIGTSTP)
        kill(process, SIGTSTP);
#endif
}
\f
/* Given FD, obtain pty buffer size. When no luck, a good guess is made,
   so that the function works even when fd is not a pty. */

int get_pty_max_bytes(int fd)
{
        /* DEC OSF 4.0 fpathconf returns 255, but xemacs hangs on long shell
           input lines if we return 253.  252 is OK!.  So let's leave a bit
           of slack for the newline that xemacs will insert, and for those
           inevitable vendor off-by-one-or-two-or-three bugs. */
#define MAX_CANON_SLACK 10
#define SAFE_MAX_CANON (127 - MAX_CANON_SLACK)
#if defined (HAVE_FPATHCONF) && defined (_PC_MAX_CANON)
        {
                int max_canon = fpathconf(fd, _PC_MAX_CANON);
#ifdef __hpux__
                /* HP-UX 10.20 fpathconf returns 768, but this results in
                   truncated input lines, while 255 works. */
                if (max_canon > 255)
                        max_canon = 255;
#endif
                return (max_canon < 0 ? SAFE_MAX_CANON :
                        max_canon >
                        SAFE_MAX_CANON ? max_canon -
                        MAX_CANON_SLACK : max_canon);
        }
#elif defined (_POSIX_MAX_CANON)
        return (_POSIX_MAX_CANON > SAFE_MAX_CANON ?
                _POSIX_MAX_CANON - MAX_CANON_SLACK : _POSIX_MAX_CANON);
#else
        return SAFE_MAX_CANON;
#endif
}

/* Figure out the eof character for the FD. */

Bufbyte get_eof_char(int fd)
{
        const Bufbyte ctrl_d = (Bufbyte) '\004';

        if (!isatty(fd))
                return ctrl_d;
#ifdef HAVE_TERMIOS
        {
                struct termios t;
                tcgetattr(fd, &t);
#if 0
                /* What is the following line designed to do??? -mrb */
                if (strlen((const char *)t.c_cc) < (unsigned int)(VEOF + 1))
                        return ctrl_d;
                else
                        return (Bufbyte) t.c_cc[VEOF];
#endif
                return t.c_cc[VEOF] ==
                    _POSIX_VDISABLE ? ctrl_d : (Bufbyte) t.c_cc[VEOF];
        }
#else                           /* ! HAVE_TERMIOS */
        /* On Berkeley descendants, the following IOCTL's retrieve the
           current control characters.  */
#if defined (TIOCGETC)
        {
                struct tchars c;
                ioctl(fd, TIOCGETC, &c);
                return (Bufbyte) c.t_eofc;
        }
#else                           /* ! defined (TIOCGLTC) && defined (TIOCGETC) */
        /* On SYSV descendants, the TCGETA ioctl retrieves the current control
           characters.  */
#ifdef TCGETA
        {
                struct termio t;
                ioctl(fd, TCGETA, &t);
                if (strlen((const char *)t.c_cc) < (unsigned int)(VINTR + 1))
                        return ctrl_d;
                else
                        return (Bufbyte) t.c_cc[VINTR];
        }
#else                           /* ! defined (TCGETA) */
        /* Rather than complain, we'll just guess ^D, which is what
         * earlier emacsen always used. */
        return ctrl_d;
#endif                          /* ! defined (TCGETA) */
#endif                          /* ! defined (TIOCGETC) */
#endif                          /* ! defined (HAVE_TERMIOS) */
}

/* Set the logical window size associated with descriptor FD
   to HEIGHT and WIDTH.  This is used mainly with ptys.  */

int set_window_size(int fd, int height, int width)
{
#ifdef TIOCSWINSZ

        /* BSD-style.  */
        struct winsize size;
        size.ws_row = height;
        size.ws_col = width;

        if (ioctl(fd, TIOCSWINSZ, &size) == -1)
                return 0;       /* error */
        else
                return 1;

#elif defined (TIOCSSIZE)

        /* SunOS - style.  */
        struct ttysize size;
        size.ts_lines = height;
        size.ts_cols = width;

        if (ioctl(fd, TIOCGSIZE, &size) == -1)
                return 0;
        else
                return 1;
#else
        return -1;
#endif
}

#ifdef HAVE_PTYS

/* Set up the proper status flags for use of a pty.  */

void setup_pty(int fd)
{
        /* I'm told that TIOCREMOTE does not mean control chars
           "can't be sent" but rather that they don't have
           input-editing or signaling effects.
           That should be good, because we have other ways
           to do those things in Emacs.
           However, telnet mode seems not to work on 4.2.
           So TIOCREMOTE is turned off now. */

        /* Under hp-ux, if TIOCREMOTE is turned on, some calls
           will hang.  In particular, the "timeout" feature (which
           causes a read to return if there is no data available)
           does this.  Also it is known that telnet mode will hang
           in such a way that Emacs must be stopped (perhaps this
           is the same problem).

           If TIOCREMOTE is turned off, then there is a bug in
           hp-ux which sometimes loses data.  Apparently the
           code which blocks the master process when the internal
           buffer fills up does not work.  Other than this,
           though, everything else seems to work fine.

           Since the latter lossage is more benign, we may as well
           lose that way.  -- cph */
#if defined (FIONBIO) && defined (SYSV_PTYS)
        {
                int on = 1;
                ioctl(fd, FIONBIO, &on);
        }
#endif
#ifdef IBMRTAIX
        /* On AIX, the parent gets SIGHUP when a pty attached child dies.  So, we */
        /* ignore SIGHUP once we've started a child on a pty.  Note that this may */
        /* cause EMACS not to die when it should, i.e., when its own controlling  */
        /* tty goes away.  I've complained to the AIX developers, and they may    */
        /* change this behavior, but I'm not going to hold my breath.             */
        signal(SIGHUP, SIG_IGN);
#endif
#ifdef TIOCPKT
        /* In some systems (Linux through 2.0.0, at least), packet mode doesn't
           get cleared when a pty is closed, so we need to clear it here.
           Linux pre2.0.13 contained an attempted fix for this (from Ted Ts'o,
           tytso@mit.edu), but apparently it messed up rlogind and telnetd, so he
           removed the fix in pre2.0.14.     - dkindred@cs.cmu.edu
         */
        {
                int off = 0;
                ioctl(fd, TIOCPKT, (char *)&off);
        }
#endif
}
#endif                          /* HAVE_PTYS */
\f
/************************************************************************/
/*                            TTY control                               */
/************************************************************************/

/* ------------------------------------------------------ */
/*                     get baud rate                      */
/* ------------------------------------------------------ */

/* It really makes more sense for the baud-rate to be console-specific
   and not device-specific, but it's (at least potentially) used for output
   decisions. */

void init_baud_rate(struct device *d)
{
        struct console *con = XCONSOLE(DEVICE_CONSOLE(d));
        if (DEVICE_WIN_P(d) || DEVICE_STREAM_P(d)) {
                DEVICE_BAUD_RATE(d) = 38400;
                return;
        }
#ifdef HAVE_TTY
        assert(DEVICE_TTY_P(d));
        {
                int input_fd = CONSOLE_TTY_DATA(con)->infd;
#if defined (HAVE_TERMIOS)
                struct termios sg;

                sg.c_cflag = B9600;
                tcgetattr(input_fd, &sg);
                DEVICE_TTY_DATA(d)->ospeed = cfgetospeed(&sg);
# if defined (USE_GETOBAUD) && defined (getobaud)
                /* m88k-motorola-sysv3 needs this (ghazi@noc.rutgers.edu) 9/1/94. */
                if (DEVICE_TTY_DATA(d)->ospeed == 0)
                        DEVICE_TTY_DATA(d)->ospeed = getobaud(sg.c_cflag);
# endif
#elif defined (HAVE_TERMIO)
                struct termio sg;

                sg.c_cflag = B9600;
# ifdef HAVE_TCATTR
                tcgetattr(input_fd, &sg);
# else
                ioctl(input_fd, TCGETA, &sg);
# endif
                DEVICE_TTY_DATA(d)->ospeed = sg.c_cflag & CBAUD;
#else                           /* neither TERMIOS nor TERMIO */
                struct sgttyb sg;

                sg.sg_ospeed = B9600;
                if (ioctl(input_fd, TIOCGETP, &sg) < 0)
                        abort();
                DEVICE_TTY_DATA(d)->ospeed = sg.sg_ospeed;
#endif
        }

        DEVICE_BAUD_RATE(d) =
            (DEVICE_TTY_DATA(d)->ospeed < countof(baud_convert)
             ? baud_convert[DEVICE_TTY_DATA(d)->ospeed]
             : 9600);

        if (DEVICE_BAUD_RATE(d) == 0)
                DEVICE_BAUD_RATE(d) = 1200;
#endif                          /* HAVE_TTY */
}
\f
/* ------------------------------------------------------ */
/*                       SIGIO control                    */
/* ------------------------------------------------------ */

#if defined(SIGIO) && !defined(BROKEN_SIGIO)

static void init_sigio_on_device(struct device *d)
{
        int filedesc = DEVICE_INFD(d);

#if defined (FIOSSAIOOWN)
        {                       /* HPUX stuff */
                int owner = getpid();
                int ioctl_status;
                if (DEVICE_TTY_P(d)) {
                        ioctl_status = ioctl(filedesc, FIOGSAIOOWN,
                                             &DEVICE_OLD_FCNTL_OWNER(d));
                        ioctl_status = ioctl(filedesc, FIOSSAIOOWN, &owner);
                }
#ifdef HAVE_WINDOW_SYSTEM
                else if (!DEVICE_STREAM_P(d)) {
                        ioctl_status = ioctl(filedesc, SIOCGPGRP,
                                             &DEVICE_OLD_FCNTL_OWNER(d));
                        ioctl_status = ioctl(filedesc, SIOCSPGRP, &owner);
                }
#endif
        }
#elif defined (F_SETOWN) && !defined (F_SETOWN_BUG)
        DEVICE_OLD_FCNTL_OWNER(d) = fcntl(filedesc, F_GETOWN, 0);
# ifdef F_SETOWN_SOCK_NEG
        /* stdin is a socket here */
        fcntl(filedesc, F_SETOWN, -getpid());
# else
        fcntl(filedesc, F_SETOWN, getpid());
# endif
#endif
}

static void reset_sigio_on_device(struct device *d)
{
        int filedesc = DEVICE_INFD(d);

#if defined (FIOSSAIOOWN)
        {                       /* HPUX stuff */
                int ioctl_status;
                if (DEVICE_TTY_P(d)) {
                        ioctl_status = ioctl(filedesc, FIOSSAIOOWN,
                                             &DEVICE_OLD_FCNTL_OWNER(d));
                }
#ifdef HAVE_WINDOW_SYSTEM
                else if (!DEVICE_STREAM_P(d)) {
                        ioctl_status = ioctl(filedesc, SIOCSPGRP,
                                             &DEVICE_OLD_FCNTL_OWNER(d));
                }
#endif
        }
#elif defined (F_SETOWN) && !defined (F_SETOWN_BUG)
        fcntl(filedesc, F_SETOWN, DEVICE_OLD_FCNTL_OWNER(d));
#endif
}

static void request_sigio_on_device(struct device *d)
{
        int filedesc = DEVICE_INFD(d);

#if defined (I_SETSIG) && !defined(HPUX10) && !defined(LINUX)
        {
                int events = 0;
                ioctl(filedesc, I_GETSIG, &events);
                ioctl(filedesc, I_SETSIG, events | S_INPUT);
        }
#elif defined (FASYNC)
        fcntl(filedesc, F_SETFL, fcntl(filedesc, F_GETFL, 0) | FASYNC);
#elif defined (FIOSSAIOSTAT)
        {
                /* DG: Changed for HP-UX. HP-UX uses different IOCTLs for
                   sockets and other devices for some bizarre reason. We guess
                   that an X device is a socket, and tty devices aren't. We then
                   use the following crud to do the appropriate thing. */
                int on = 1;
                int ioctl_status;       /* ####DG: check if IOCTL succeeds here. */

                if (DEVICE_TTY_P(d)) {
                        ioctl_status = ioctl(filedesc, FIOSSAIOSTAT, &on);
                }
#ifdef HAVE_WINDOW_SYSTEM
                else if (!DEVICE_STREAM_P(d)) {
                        ioctl_status = ioctl(filedesc, FIOASYNC, &on);
                }
#endif
        }
#elif defined (FIOASYNC)
        {
                int on = 1;
                ioctl(filedesc, FIOASYNC, &on);
        }
#endif

#if defined (_CX_UX)            /* #### Is this crap necessary? */
        EMACS_UNBLOCK_SIGNAL(SIGIO);
#endif
}

static void unrequest_sigio_on_device(struct device *d)
{
        int filedesc = DEVICE_INFD(d);

#if defined (I_SETSIG) && !defined(HPUX10)
        {
                int events = 0;
                ioctl(filedesc, I_GETSIG, &events);
                ioctl(filedesc, I_SETSIG, events & ~S_INPUT);
        }
#elif defined (FASYNC)
        fcntl(filedesc, F_SETFL, fcntl(filedesc, F_GETFL, 0) & ~FASYNC);
#elif defined (FIOSSAIOSTAT)
        {
                /* DG: Changed for HP-UX. HP-UX uses different IOCTLs for
                   sockets and other devices for some bizarre reason. We guess
                   that an X device is a socket, and tty devices aren't. We then
                   use the following crud to do the appropriate thing. */

                int off = 0;
                int ioctl_status;

                /* See comment for request_sigio_on_device */

                if (DEVICE_TTY_P(d)) {
                        ioctl_status = ioctl(filedesc, FIOSSAIOSTAT, &off);
                } else {
                        ioctl_status = ioctl(filedesc, FIOASYNC, &off);
                }
        }
#elif defined (FIOASYNC)
        {
                int off = 0;
                ioctl(filedesc, FIOASYNC, &off);
        }
#endif
}

void request_sigio(void)
{
        Lisp_Object devcons, concons;

        DEVICE_LOOP_NO_BREAK(devcons, concons) {
                struct device *d;

                d = XDEVICE(XCAR(devcons));

                if (!DEVICE_STREAM_P(d))
                        request_sigio_on_device(d);
        }
}

void unrequest_sigio(void)
{
        Lisp_Object devcons, concons;

        DEVICE_LOOP_NO_BREAK(devcons, concons) {
                struct device *d;

                d = XDEVICE(XCAR(devcons));

                if (!DEVICE_STREAM_P(d))
                        unrequest_sigio_on_device(d);
        }
}

#endif                          /* SIGIO */
\f
/* ------------------------------------------------------ */
/*             Changing Emacs's process group             */
/* ------------------------------------------------------ */

/* Saving and restoring the process group of Emacs's terminal.  */

/* On some systems, apparently (?!) Emacs must be in its own process
   group in order to receive SIGIO correctly.  On other systems
   (e.g. Solaris), it's not required and doing it makes things
   get fucked up.  So, we only do it when
   SIGIO_REQUIRES_SEPARATE_PROCESS_GROUP is defined.  Basically,
   this is only required for BSD 4.2 systems. (Actually, I bet
   we don't have to do this at all -- those systems also
   required interrupt input, which we don't support.)

   If Emacs was in its own process group (i.e. inherited_pgroup ==
   getpid ()), then we know we're running under a shell with job
   control (Emacs would never be run as part of a pipeline).
   Everything is fine.

   If Emacs was not in its own process group, then we know we're
   running under a shell (or a caller) that doesn't know how to
   separate itself from Emacs (like sh).  Emacs must be in its own
   process group in order to receive SIGIO correctly.  In this
   situation, we put ourselves in our own pgroup, forcibly set the
   tty's pgroup to our pgroup, and make sure to restore and reinstate
   the tty's pgroup just like any other terminal setting.  If
   inherited_group was not the tty's pgroup, then we'll get a
   SIGTTmumble when we try to change the tty's pgroup, and a CONT if
   it goes foreground in the future, which is what should happen.  */

#ifdef SIGIO_REQUIRES_SEPARATE_PROCESS_GROUP

static pid_t inherited_pgroup;
static pid_t inherited_tty_pgroup;

#endif

void munge_tty_process_group(void)
{
#ifdef SIGIO_REQUIRES_SEPARATE_PROCESS_GROUP
        if (noninteractive)
                return;

        /* Only do this munging if we have a device on the controlling
           terminal.  See the large comment below. */

        if (CONSOLEP(Vcontrolling_terminal) &&
            CONSOLE_LIVE_P(XCONSOLE(Vcontrolling_terminal))) {
                int fd = open("/dev/tty", O_RDWR, 0);
                pid_t me = getpid();
                EMACS_BLOCK_SIGNAL(SIGTTOU);
                EMACS_SET_TTY_PROCESS_GROUP(fd, &me);
                EMACS_UNBLOCK_SIGNAL(SIGTTOU);
                close(fd);
        }
#endif
}

/* Split off the foreground process group to Emacs alone.
   When we are in the foreground, but not started in our own process
   group, redirect the TTY to point to our own process group.  We need
   to be in our own process group to receive SIGIO properly.  */
static void munge_process_groups(void)
{
#ifdef SIGIO_REQUIRES_SEPARATE_PROCESS_GROUP
        if (noninteractive)
                return;

        EMACS_SEPARATE_PROCESS_GROUP();

        munge_tty_process_group();
#endif
}

void unmunge_tty_process_group(void)
{
#ifdef SIGIO_REQUIRES_SEPARATE_PROCESS_GROUP
        {
                int fd = open("/dev/tty", O_RDWR, 0);
                EMACS_BLOCK_SIGNAL(SIGTTOU);
                EMACS_SET_TTY_PROCESS_GROUP(fd, &inherited_tty_pgroup);
                EMACS_UNBLOCK_SIGNAL(SIGTTOU);
                close(fd);
        }
#endif
}

/* Set the tty to our original foreground group.
   Also restore the original process group (put us back into sh's
   process group), so that ^Z will suspend both us and sh. */
static void unmunge_process_groups(void)
{
#ifdef SIGIO_REQUIRES_SEPARATE_PROCESS_GROUP
        if (noninteractive)
                return;

        unmunge_tty_process_group();

        EMACS_SET_PROCESS_GROUP(inherited_pgroup);
#endif
}

/* According to some old wisdom, we need to be in a separate process
   group for SIGIO to work correctly (at least on some systems ...).
   So go ahead and put ourselves into our own process group.  This
   will fail if we're already in our own process group, but who cares.
   Also record whether we were in our own process group. (In general,
   we will already be in our own process group if we were started from
   a job-control shell like csh, but not if we were started from sh).

   If we succeeded in changing our process group, then we will no
   longer be in the foreground process group of our controlling
   terminal.  Therefore, if we have a console open onto this terminal,
   we have to change the controlling terminal's foreground process
   group (otherwise we will get stopped with a SIGTTIN signal when
   attempting to read from the terminal).  It's important,
   however, that we do this *only* when we have a console open onto
   the terminal.  It's a decidedly bad idea to do so otherwise,
   especially if XEmacs was started from the background. */

void init_process_group(void)
{
#ifdef SIGIO_REQUIRES_SEPARATE_PROCESS_GROUP
        if (!noninteractive) {
                int fd = open("/dev/tty", O_RDWR, 0);
                inherited_pgroup = EMACS_GET_PROCESS_GROUP();
                EMACS_GET_TTY_PROCESS_GROUP(fd, &inherited_tty_pgroup);
                close(fd);
                EMACS_SEPARATE_PROCESS_GROUP();
        }
#endif
}

void disconnect_controlling_terminal(void)
{
#  ifdef HAVE_SETSID
        /* Controlling terminals are attached to a session.
           Create a new session for us; it will have no controlling
           terminal.  This also, of course, puts us in our own
           process group. */
        setsid();
#  else
        /* Put us in our own process group. */
        EMACS_SEPARATE_PROCESS_GROUP();
#    if defined (TIOCNOTTY)
        /* This is the older way of disconnecting the controlling
           terminal, on 4.3 BSD.  We must open /dev/tty; using
           filedesc 0 is not sufficient because it could be
           something else (e.g. our stdin was redirected to
           another terminal).
         */
        {
                int j = open("/dev/tty", O_RDWR, 0);
                ioctl(j, TIOCNOTTY, 0);
                close(j);
        }
#    endif                      /* TIOCNOTTY */
        /*
           On systems without TIOCNOTTY and without
           setsid(), we don't need to do anything more to
           disconnect our controlling terminal.  Here is
           what the man page for termio(7) from a SYSV 3.2
           system says:

           "The first terminal file opened by the process group leader
           of a terminal file not already associated with a process
           group becomes the control terminal for that process group.
           The control terminal plays a special role in handling quit
           and interrupt signals, as discussed below.  The control
           terminal is inherited by a child process during a fork(2).
           A process can break this association by changing its process
           group using setpgrp(2)."

         */
#  endif                        /* not HAVE_SETSID */
}
\f
/* ------------------------------------------------------ */
/*        Getting and setting emacs_tty structures        */
/* ------------------------------------------------------ */

/* It's wrong to encase these into #ifdef HAVE_TTY because we need
   them for child TTY processes.  */
/* However, this does break NT support while we don't do child TTY processes */

/* Set *TC to the parameters associated with the terminal FD.
   Return zero if all's well, or -1 if we ran into an error we
   couldn't deal with.  */
int emacs_get_tty(int fd, struct emacs_tty *settings)
{
        /* Retrieve the primary parameters - baud rate, character size, etcetera.  */
#ifdef HAVE_TCATTR
        /* We have those nifty POSIX tcmumbleattr functions.  */
        if (tcgetattr(fd, &settings->main) < 0)
                return -1;

#elif defined HAVE_TERMIO
        /* The SYSV-style interface?  */
        if (ioctl(fd, TCGETA, &settings->main) < 0)
                return -1;

#else
        /* I give up - I hope you have the BSD ioctls.  */
        if (ioctl(fd, TIOCGETP, &settings->main) < 0)
                return -1;
#endif                          /* HAVE_TCATTR */

        /* Suivant - Do we have to get struct ltchars data?  */
#ifdef HAVE_LTCHARS
        if (ioctl(fd, TIOCGLTC, &settings->ltchars) < 0)
                return -1;
#endif

        /* How about a struct tchars and a wordful of lmode bits?  */
#ifdef HAVE_TCHARS
        if (ioctl(fd, TIOCGETC, &settings->tchars) < 0
            || ioctl(fd, TIOCLGET, &settings->lmode) < 0)
                return -1;
#endif

        /* We have survived the tempest.  */
        return 0;
}

/* Set the parameters of the tty on FD according to the contents of
   *SETTINGS.  If FLUSHP is non-zero, we discard input.
   Return 0 if all went well, and -1 if anything failed.
   #### All current callers use FLUSHP == 0. */

int emacs_set_tty(int fd, struct emacs_tty *settings, int flushp)
{
        /* Set the primary parameters - baud rate, character size, etcetera.  */
#ifdef HAVE_TCATTR
        int i;
        /* We have those nifty POSIX tcmumbleattr functions.
           William J. Smith <wjs@wiis.wang.com> writes:
           "POSIX 1003.1 defines tcsetattr() to return success if it was
           able to perform any of the requested actions, even if some
           of the requested actions could not be performed.
           We must read settings back to ensure tty setup properly.
           AIX requires this to keep tty from hanging occasionally."  */
        /* This makes sure that we don't loop indefinitely in here.  */
        for (i = 0; i < 10; i++)
                if (tcsetattr
                    (fd, flushp ? TCSAFLUSH : TCSADRAIN, &settings->main) < 0) {
                        if (errno == EINTR)
                                continue;
                        else
                                return -1;
                } else {
                        struct termios new;

                        /* Get the current settings, and see if they're what we asked for.  */
                        tcgetattr(fd, &new);
                        /* We cannot use memcmp on the whole structure here because under
                         * aix386 the termios structure has some reserved field that may
                         * not be filled in.
                         */
                        if (new.c_iflag == settings->main.c_iflag
                            && new.c_oflag == settings->main.c_oflag
                            && new.c_cflag == settings->main.c_cflag
                            && new.c_lflag == settings->main.c_lflag
                            && memcmp(new.c_cc, settings->main.c_cc, NCCS) == 0)
                                break;
                        else
                                continue;
                }
#elif defined HAVE_TERMIO
        /* The SYSV-style interface?  */
        if (ioctl(fd, flushp ? TCSETAF : TCSETAW, &settings->main) < 0)
                return -1;

#else
        /* I give up - I hope you have the BSD ioctls.  */
        if (ioctl(fd, (flushp) ? TIOCSETP : TIOCSETN, &settings->main) < 0)
                return -1;
#endif                          /* HAVE_TCATTR */

        /* Suivant - Do we have to get struct ltchars data?  */
#ifdef HAVE_LTCHARS
        if (ioctl(fd, TIOCSLTC, &settings->ltchars) < 0)
                return -1;
#endif

        /* How about a struct tchars and a wordful of lmode bits?  */
#ifdef HAVE_TCHARS
        if (ioctl(fd, TIOCSETC, &settings->tchars) < 0
            || ioctl(fd, TIOCLSET, &settings->lmode) < 0)
                return -1;
#endif

        /* We have survived the tempest.  */
        return 0;
}

\f
/* ------------------------------------------------------ */
/*                 Initializing a device                  */
/* ------------------------------------------------------ */

#ifdef HAVE_TTY

/* This may also be defined in stdio,
   but if so, this does no harm,
   and using the same name avoids wasting the other one's space.  */

#if ((defined(USG) || defined(DGUX)) && !defined(__STDC__))
char _sobuf[BUFSIZ + 8];
#elif (defined(USG) && !defined(LINUX) && !defined(_SCO_DS)) || defined(IRIX5)
extern unsigned char _sobuf[BUFSIZ + 8];
#else
char _sobuf[BUFSIZ];
#endif

#if defined (TIOCGLTC) && defined (HAVE_LTCHARS)        /* HAVE_LTCHARS */
static struct ltchars new_ltchars = { -1, -1, -1, -1, -1, -1 };
#endif
#ifdef TIOCGETC                 /* HAVE_TCHARS */
#ifdef HAVE_TCHARS
static struct tchars new_tchars = { -1, -1, -1, -1, -1, -1 };
#endif
#endif

static void tty_init_sys_modes_on_device(struct device *d)
{
        struct emacs_tty tty;
        int input_fd, output_fd;
        struct console *con = XCONSOLE(DEVICE_CONSOLE(d));

        input_fd = CONSOLE_TTY_DATA(con)->infd;
        output_fd = CONSOLE_TTY_DATA(con)->outfd;

        emacs_get_tty(input_fd, &CONSOLE_TTY_DATA(con)->old_tty);
        tty = CONSOLE_TTY_DATA(con)->old_tty;

        con->tty_erase_char = Qnil;

#if defined (HAVE_TERMIO) || defined (HAVE_TERMIOS)
        /* after all those years... */
        con->tty_erase_char = make_char(tty.main.c_cc[VERASE]);
#ifdef DGUX
        /* This allows meta to be sent on 8th bit.  */
        tty.main.c_iflag &= ~INPCK;     /* don't check input for parity */
#endif
        tty.main.c_iflag |= (IGNBRK);   /* Ignore break condition */
        tty.main.c_iflag &= ~ICRNL;     /* Disable map of CR to NL on input */
#ifdef ISTRIP
        tty.main.c_iflag &= ~ISTRIP;    /* don't strip 8th bit on input */
#endif
        tty.main.c_lflag &= ~ECHO;      /* Disable echo */
        tty.main.c_lflag &= ~ICANON;    /* Disable erase/kill processing */
#ifdef IEXTEN
        tty.main.c_lflag &= ~IEXTEN;    /* Disable other editing characters.  */
#endif
        tty.main.c_lflag |= ISIG;       /* Enable signals */
        if (TTY_FLAGS(con).flow_control) {
                tty.main.c_iflag |= IXON;       /* Enable start/stop output control */
#ifdef IXANY
                tty.main.c_iflag &= ~IXANY;
#endif                          /* IXANY */
        } else
                tty.main.c_iflag &= ~IXON;      /* Disable start/stop output control */
        tty.main.c_oflag &= ~ONLCR;     /* Disable map of NL to CR-NL
                                           on output */
        tty.main.c_oflag &= ~TAB3;      /* Disable tab expansion */
#ifdef CS8
        if (TTY_FLAGS(con).meta_key) {
                tty.main.c_cflag |= CS8;        /* allow 8th bit on input */
                tty.main.c_cflag &= ~PARENB;    /* Don't check parity */
        }
#endif
        if (CONSOLE_TTY_DATA(con)->controlling_terminal) {
                tty.main.c_cc[VINTR] = CONSOLE_QUIT_CHAR(con);  /* C-g (usually) gives SIGINT */
                /* Set up C-g for both SIGQUIT and SIGINT.
                   We don't know which we will get, but we handle both alike
                   so which one it really gives us does not matter.  */
                tty.main.c_cc[VQUIT] = CONSOLE_QUIT_CHAR(con);
        } else {
                tty.main.c_cc[VINTR] = _POSIX_VDISABLE;
                tty.main.c_cc[VQUIT] = _POSIX_VDISABLE;
        }
        tty.main.c_cc[VMIN] = 1;        /* Input should wait for at
                                           least 1 char */
        tty.main.c_cc[VTIME] = 0;       /* no matter how long that takes.  */
#ifdef VSWTCH
        tty.main.c_cc[VSWTCH] = _POSIX_VDISABLE;        /* Turn off shell layering use
                                                           of C-z */
#endif                          /* VSWTCH */
        /* There was some conditionalizing here on (mips or TCATTR), but
           I think that's wrong.  There was one report of C-y (DSUSP) not being
           disabled on HP9000s700 systems, and this might fix it. */
#ifdef VSUSP
        tty.main.c_cc[VSUSP] = _POSIX_VDISABLE; /* Turn off mips handling of C-z. */
#endif                          /* VSUSP */
#ifdef V_DSUSP
        tty.main.c_cc[V_DSUSP] = _POSIX_VDISABLE;       /* Turn off mips handling of C-y. */
#endif                          /* V_DSUSP */
#ifdef VDSUSP                   /* Some systems have VDSUSP, some have V_DSUSP.  */
        tty.main.c_cc[VDSUSP] = _POSIX_VDISABLE;
#endif                          /* VDSUSP */
#ifdef VLNEXT
        tty.main.c_cc[VLNEXT] = _POSIX_VDISABLE;
#endif                          /* VLNEXT */
#ifdef VREPRINT
        tty.main.c_cc[VREPRINT] = _POSIX_VDISABLE;
#endif                          /* VREPRINT */
#ifdef VWERASE
        tty.main.c_cc[VWERASE] = _POSIX_VDISABLE;
#endif                          /* VWERASE */
#ifdef VDISCARD
        tty.main.c_cc[VDISCARD] = _POSIX_VDISABLE;
#endif                          /* VDISCARD */
#ifdef VSTART
        tty.main.c_cc[VSTART] = _POSIX_VDISABLE;
#endif                          /* VSTART */
#ifdef VSTRT
        tty.main.c_cc[VSTRT] = _POSIX_VDISABLE; /* called VSTRT on some systems */
#endif                          /* VSTART */
#ifdef VSTOP
        tty.main.c_cc[VSTOP] = _POSIX_VDISABLE;
#endif                          /* VSTOP */
#ifdef SET_LINE_DISCIPLINE
        /* Need to explicitly request TERMIODISC line discipline or
           Ultrix's termios does not work correctly.  */
        tty.main.c_line = SET_LINE_DISCIPLINE;
#endif

#ifdef AIX
#ifndef IBMR2AIX
        /* AIX enhanced edit loses NULs, so disable it. */
        tty.main.c_line = 0;
        tty.main.c_iflag &= ~ASCEDIT;
#else
        tty.main.c_cc[VSTRT] = 255;
        tty.main.c_cc[VSTOP] = 255;
        tty.main.c_cc[VSUSP] = 255;
        tty.main.c_cc[VDSUSP] = 255;
#endif                          /* IBMR2AIX */
        /* Also, PTY overloads NUL and BREAK.
           don't ignore break, but don't signal either, so it looks like NUL.
           This really serves a purpose only if running in an XTERM window
           or via TELNET or the like, but does no harm elsewhere.  */
        tty.main.c_iflag &= ~IGNBRK;
        tty.main.c_iflag &= ~BRKINT;
#endif                          /* AIX */
#else                           /* if not HAVE_TERMIO */
        con->tty_erase_char = make_char(tty.main.sg_erase);
        tty.main.sg_flags &= ~(ECHO | CRMOD | XTABS);
        if (TTY_FLAGS(con).meta_key)
                tty.main.sg_flags |= ANYP;
        /* #### should we be using RAW mode here? */
        tty.main.sg_flags |= /* interrupt_input ? RAW : */ CBREAK;
#endif                          /* not HAVE_TERMIO */

        /* If going to use CBREAK mode, we must request C-g to interrupt
           and turn off start and stop chars, etc.  If not going to use
           CBREAK mode, do this anyway so as to turn off local flow
           control for user coming over network on 4.2; in this case,
           only t_stopc and t_startc really matter.  */
#ifndef HAVE_TERMIO
#ifdef HAVE_TCHARS
        /* Note: if not using CBREAK mode, it makes no difference how we
           set this */
        tty.tchars = new_tchars;
        tty.tchars.t_intrc = CONSOLE_QUIT_CHAR(con);
        if (TTY_FLAGS(con).flow_control) {
                tty.tchars.t_startc = '\021';
            &nb