bin/less/ttyin.c

   1 /*
   2  * Copyright (C) 1984-2012  Mark Nudelman
   3  * Modified for use with illumos by Garrett D'Amore.
   4  * Copyright 2014 Garrett D'Amore <garrett@damore.org>
   5  *
   6  * You may distribute under the terms of either the GNU General Public
   7  * License or the Less License, as specified in the README file.
   8  *
   9  * For more information, see the README file.
  10  */
  11
  12 /*
  13  * Routines dealing with getting input from the keyboard (i.e. from the user).
  14  */
  15
  16 #include "less.h"
  17
  18 int tty;
  19 extern volatile sig_atomic_t sigs;
  20 extern int utf_mode;
  21
  22 /*
  23  * Open keyboard for input.
  24  */
  25 void
  26 open_getchr(void)
  27 {
  28         /*
  29          * Try /dev/tty.
  30          * If that doesn't work, use file descriptor 2,
  31          * which in Unix is usually attached to the screen,
  32          * but also usually lets you read from the keyboard.
  33          */
  34         tty = open("/dev/tty", O_RDONLY);
  35         if (tty < 0)
  36                 tty = STDERR_FILENO;
  37 }
  38
  39 /*
  40  * Get a character from the keyboard.
  41  */
  42 int
  43 getchr(void)
  44 {
  45         unsigned char c;
  46         int result;
  47
  48         do {
  49                 result = iread(tty, &c, sizeof (char));
  50                 if (result == READ_INTR)
  51                         return (READ_INTR);
  52                 if (result < 0) {
  53                         /*
  54                          * Don't call error() here,
  55                          * because error calls getchr!
  56                          */
  57                         quit(QUIT_ERROR);
  58                 }
  59                 /*
  60                  * Various parts of the program cannot handle
  61                  * an input character of '\0'.
  62                  * If a '\0' was actually typed, convert it to '\340' here.
  63                  */
  64                 if (c == '\0')
  65                         c = 0340;
  66         } while (result != 1);
  67
  68         return (c & 0xFF);
  69 }