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ttyin.c revision 1.1 
      1 /*
      2  * Copyright (c) 1988 Mark Nudleman
      3  * Copyright (c) 1988, 1993
      4  *	The Regents of the University of California.  All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. All advertising materials mentioning features or use of this software
     15  *    must display the following acknowledgement:
     16  *	This product includes software developed by the University of
     17  *	California, Berkeley and its contributors.
     18  * 4. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #ifndef lint
     36 static char sccsid[] = "@(#)ttyin.c	8.1 (Berkeley) 6/6/93";
     37 #endif /* not lint */
     38 
     39 /*
     40  * Routines dealing with getting input from the keyboard (i.e. from the user).
     41  */
     42 
     43 #include <less.h>
     44 
     45 static int tty;
     46 
     47 /*
     48  * Open keyboard for input.
     49  * (Just use file descriptor 2.)
     50  */
     51 open_getchr()
     52 {
     53 	tty = 2;
     54 }
     55 
     56 /*
     57  * Get a character from the keyboard.
     58  */
     59 getchr()
     60 {
     61 	char c;
     62 	int result;
     63 
     64 	do
     65 	{
     66 		result = iread(tty, &c, 1);
     67 		if (result == READ_INTR)
     68 			return (READ_INTR);
     69 		if (result < 0)
     70 		{
     71 			/*
     72 			 * Don't call error() here,
     73 			 * because error calls getchr!
     74 			 */
     75 			quit();
     76 		}
     77 	} while (result != 1);
     78 	return (c & 0177);
     79 }
     80