xref: /src/bin/ksh/tty.c

/*	$NetBSD: tty.c,v 1.10 2021/07/24 21:31:31 andvar Exp $	*/

#include <sys/cdefs.h>

#ifndef lint
__RCSID("$NetBSD: tty.c,v 1.10 2021/07/24 21:31:31 andvar Exp $");
#endif

#include <sys/stat.h>

#include "sh.h"
#define EXTERN
#include "tty.h"
#undef EXTERN

int
get_tty(fd, ts)
	int fd;
	TTY_state *ts;
{
	int ret;

# ifdef HAVE_TERMIOS_H
	ret = tcgetattr(fd, ts);
# else /* HAVE_TERIOS_H */
#  ifdef HAVE_TERMIO_H
	ret = ioctl(fd, TCGETA, ts);
#  else /* HAVE_TERMIO_H */
	ret = ioctl(fd, TIOCGETP, &ts->sgttyb);
#   ifdef TIOCGATC
	if (ioctl(fd, TIOCGATC, &ts->lchars) < 0)
		ret = -1;
#   else
	if (ioctl(fd, TIOCGETC, &ts->tchars) < 0)
		ret = -1;
#    ifdef TIOCGLTC
	if (ioctl(fd, TIOCGLTC, &ts->ltchars) < 0)
		ret = -1;
#    endif /* TIOCGLTC */
#   endif /* TIOCGATC */
#  endif /* HAVE_TERMIO_H */
# endif /* HAVE_TERIOS_H */
	return ret;
}

int
set_tty(fd, ts, flags)
	int fd;
	TTY_state *ts;
	int flags;
{
	int ret = 0;

# ifdef HAVE_TERMIOS_H
	ret = tcsetattr(fd, TCSADRAIN, ts);
# else /* HAVE_TERIOS_H */
#  ifdef HAVE_TERMIO_H
#   ifndef TCSETAW				/* e.g. Cray-2 */
		/* first wait for output to drain */
#    ifdef TCSBRK
		if (ioctl(tty_fd, TCSBRK, 1) < 0)
			ret = -1;
#    else /* the following kludge is minimally intrusive, but sometimes fails */
		if (flags & TF_WAIT)
			sleep((unsigned)1);	/* fake it */
#    endif
#   endif /* !TCSETAW */
#   if defined(_BSD_SYSV) || !defined(TCSETAW)
/* _BSD_SYSV must force TIOCSETN instead of TIOCSETP (preserve type-ahead) */
		if (ioctl(tty_fd, TCSETA, ts) < 0)
			ret = -1;
#   else
		if (ioctl(tty_fd, TCSETAW, ts) < 0)
			ret = -1;
#   endif
#  else /* HAVE_TERMIO_H */
	    ret = ioctl(fd, TIOCSETN, &ts->sgttyb);
#   ifdef TIOCGATC
	if (ioctl(fd, TIOCSATC, &ts->lchars) < 0)
		ret = -1;
#   else
	if (ioctl(fd, TIOCSETC, &ts->tchars) < 0)
		ret = -1;
#    ifdef TIOCGLTC
	if (ioctl(fd, TIOCSLTC, &ts->ltchars) < 0)
		ret = -1;
#    endif /* TIOCGLTC */
#   endif /* TIOCGATC */
#  endif /* HAVE_TERMIO_H */
# endif /* HAVE_TERIOS_H */
	return ret;
}


/* Initialize tty_fd.  Used for saving/resetting tty modes upon
 * foreground job completion and for setting up tty process group.
 */
void
tty_init(init_ttystate)
	int init_ttystate;
{
	int	do_close = 1;
	int	tfd;
	const char	*devtty = _PATH_TTY;

	if (tty_fd >= 0) {
		close(tty_fd);
		tty_fd = -1;
	}
	tty_devtty = 1;

	if ((tfd = open(devtty, O_RDWR, 0)) < 0) {
		if (tfd < 0) {
			tty_devtty = 0;
			warningf(false,
				"No controlling tty (open %s: %s)",
				devtty, strerror(errno));
		}
	}

	if (tfd < 0) {
		do_close = 0;
		if (isatty(0))
			tfd = 0;
		else if (isatty(2))
			tfd = 2;
		else {
			warningf(false, "Can't find tty file descriptor");
			return;
		}
	}
	if ((tty_fd = ksh_dupbase(tfd, FDBASE)) < 0) {
		warningf(false, "j_ttyinit: dup of tty fd failed: %s",
			strerror(errno));
	} else if (fd_clexec(tty_fd) < 0) {
		warningf(false, "j_ttyinit: can't set close-on-exec flag: %s",
			strerror(errno));
		close(tty_fd);
		tty_fd = -1;
	} else if (init_ttystate)
		get_tty(tty_fd, &tty_state);
	if (do_close)
		close(tfd);
}

void
tty_close()
{
	if (tty_fd >= 0) {
		close(tty_fd);
		tty_fd = -1;
	}
}