usr/src/usr.bin/more/ttyin.c

/*
 * Copyright (c) 1988 Mark Nudleman
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mark Nudleman.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static char sccsid[] = "@(#)ttyin.c     5.1 (Berkeley) %G%";
#endif /* not lint */

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

#include "less.h"

static int tty;

/*
 * Open keyboard for input.
 * (Just use file descriptor 2.)
 */
        public void
open_getchr()
{
        tty = 2;
}

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

        do
        {
                result = iread(tty, &c, 1);
                if (result == READ_INTR)
                        return (READ_INTR);
                if (result < 0)
                {
                        /*
                         * Don't call error() here,
                         * because error calls getchr!
                         */
                        quit();
                }
        } while (result != 1);
        return (c & 0177);
}