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$OpenBSD$

/*	$OpenBSD: ttyin.c,v 1.2 2001/01/29 01:58:04 niklas Exp $	*/

/*
 * Copyright (c) 1984,1985,1989,1994,1995  Mark Nudelman
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice in the documentation and/or other materials provided with 
 *    the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN 
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


/*
 * Routines dealing with getting input from the keyboard (i.e. from the user).
 */

#include "less.h"

static int tty;

/*
 * Open keyboard for input.
 */
	public void
open_getchr()
{
#if MSOFTC || OS2
	extern int fd0;
	/*
	 * Open a new handle to CON: in binary mode 
	 * for unbuffered keyboard read.
	 */
	 fd0 = dup(0);
	 close(0);
	 tty = OPEN_TTYIN();
#else
	/*
	 * Try /dev/tty.
	 * If that doesn't work, use file descriptor 2,
	 * which in Unix is usually attached to the screen,
	 * but also usually lets you read from the keyboard.
	 */
	tty = OPEN_TTYIN();
	if (tty < 0)
		tty = 2;
#endif
}

/*
 * Get a character from the keyboard.
 */
	public int
getchr()
{
	char c;
	int result;

	do
	{
#if MSOFTC
		/*
		 * In raw read, we don't see ^C so look here for it.
		 */
		flush();
		c = getch();
		result = 1;
		if (c == '\003')
			return (READ_INTR);
#else
#if OS2
		flush();
		while (_read_kbd(0, 0, 0) != -1)
			continue;
		if ((c = _read_kbd(0, 1, 0)) == -1)
			return (READ_INTR);
		result = 1;
#else
		result = iread(tty, &c, sizeof(char));
		if (result == READ_INTR)
			return (READ_INTR);
		if (result < 0)
		{
			/*
			 * Don't call error() here,
			 * because error calls getchr!
			 */
			quit(QUIT_ERROR);
		}
#endif
#endif
		/*
		 * Various parts of the program cannot handle
		 * an input character of '\0'.
		 * If a '\0' was actually typed, convert it to '\340' here.
		 */
		if (c == '\0')
			c = '\340';
	} while (result != 1);

	return (c & 0377);
}