--- less-378/screen.c.orig	2002-09-30 21:57:15 +0400
+++ less-378/screen.c	2002-10-02 13:14:32 +0400
@@ -237,6 +237,18 @@ extern int hilite_search;
 extern char *tgetstr();
 extern char *tgoto();
 
+static int screen_fd(void)
+{
+	static int fd = -1;
+	if (fd == -1)
+	{
+		for (fd = STDIN_FILENO; fd <= STDERR_FILENO; ++fd)
+			if (isatty(fd))
+				break;
+	}
+
+	return (fd <= STDERR_FILENO) ? fd : -1;
+}
 
 /*
  * Change terminal to "raw mode", or restore to "normal" mode.
@@ -268,7 +280,7 @@ raw_mode(on)
 		/*
 		 * Get terminal modes.
 		 */
-		tcgetattr(tty, &s);
+		tcgetattr(screen_fd(), &s);
 
 		/*
 		 * Save modes and set certain variables dependent on modes.
@@ -426,7 +438,7 @@ raw_mode(on)
 #if HAVE_FSYNC
 	fsync(tty);
 #endif
-	tcsetattr(tty, TCSADRAIN, &s);
+	tcsetattr(screen_fd(), TCSADRAIN, &s);
 #if MUST_SET_LINE_DISCIPLINE
 	if (!on)
 	{
@@ -436,7 +448,7 @@ raw_mode(on)
 		 * is therefore not restored, yet.  Restore the old
 		 * line discipline by hand.
 		 */
-		ioctl(tty, TIOCSETD, &save_term.c_line);
+		ioctl(screen_fd(), TIOCSETD, &save_term.c_line);
 	}
 #endif
     }
@@ -452,7 +464,7 @@ raw_mode(on)
 		/*
 		 * Get terminal modes.
 		 */
-		ioctl(tty, TCGETA, &s);
+		ioctl(screen_fd(), TCGETA, &s);
 
 		/*
 		 * Save modes and set certain variables dependent on modes.
@@ -488,7 +500,7 @@ raw_mode(on)
 		 */
 		s = save_term;
 	}
-	ioctl(tty, TCSETAW, &s);
+	ioctl(screen_fd(), TCSETAW, &s);
     }
 #else
 #ifdef TIOCGETP
@@ -502,7 +514,7 @@ raw_mode(on)
 		/*
 		 * Get terminal modes.
 		 */
-		ioctl(tty, TIOCGETP, &s);
+		ioctl(screen_fd(), TIOCGETP, &s);
 
 		/*
 		 * Save modes and set certain variables dependent on modes.
@@ -531,7 +543,7 @@ raw_mode(on)
 		 */
 		s = save_term;
 	}
-	ioctl(tty, TIOCSETN, &s);
+	ioctl(screen_fd(), TIOCSETN, &s);
     }
 #else
 #ifdef _OSK
@@ -741,7 +753,7 @@ scrsize()
 #ifdef TIOCGWINSZ
 	{
 		struct winsize w;
-		if (ioctl(2, TIOCGWINSZ, &w) == 0)
+		if (ioctl(screen_fd(), TIOCGWINSZ, &w) == 0)
 		{
 			if (w.ws_row > 0)
 				sys_height = w.ws_row;
@@ -753,7 +765,7 @@ scrsize()
 #ifdef WIOCGETD
 	{
 		struct uwdata w;
-		if (ioctl(2, WIOCGETD, &w) == 0)
+		if (ioctl(screen_fd(), WIOCGETD, &w) == 0)
 		{
 			if (w.uw_height > 0)
 				sys_height = w.uw_height / w.uw_vs;