distrib/utils/more/ttyin.c

   1 /*      $NetBSD: ttyin.c,v 1.4 2003/08/07 09:28:01 agc Exp $    */
   2
   3 /*
   4  * Copyright (c) 1988 Mark Nudelman
   5  * Copyright (c) 1988, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <sys/cdefs.h>
  34 #ifndef lint
  35 #if 0
  36 static char sccsid[] = "@(#)ttyin.c     8.1 (Berkeley) 6/6/93";
  37 #else
  38 __RCSID("$NetBSD: ttyin.c,v 1.4 2003/08/07 09:28:01 agc Exp $");
  39 #endif
  40 #endif /* not lint */
  41
  42 /*
  43  * Routines dealing with getting input from the keyboard (i.e. from the user).
  44  */
  45
  46 #include <sys/types.h>
  47
  48 #include "less.h"
  49 #include "extern.h"
  50
  51 static int tty;
  52
  53 /*
  54  * Open keyboard for input.
  55  * (Just use file descriptor 2.)
  56  */
  57 void
  58 open_getchr()
  59 {
  60         tty = 2;
  61 }
  62
  63 /*
  64  * Get a character from the keyboard.
  65  */
  66 int
  67 getchr()
  68 {
  69         char c;
  70         int result;
  71
  72         do
  73         {
  74                 result = iread(tty, &c, 1);
  75                 if (result == READ_INTR)
  76                         return (READ_INTR);
  77                 if (result < 0)
  78                 {
  79                         /*
  80                          * Don't call error() here,
  81                          * because error calls getchr!
  82                          */
  83                         quit();
  84                 }
  85         } while (result != 1);
  86         return (c & 0177);
  87 }