1 | /* Noncanonical Mode Example |
2 | Copyright (C) 1991-2024 Free Software Foundation, Inc. |
3 | |
4 | This program is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU General Public License |
6 | as published by the Free Software Foundation; either version 2 |
7 | of the License, or (at your option) any later version. |
8 | |
9 | This program is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
12 | GNU General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU General Public License |
15 | along with this program; if not, see <https://www.gnu.org/licenses/>. |
16 | */ |
17 | |
18 | #include <unistd.h> |
19 | #include <stdio.h> |
20 | #include <stdlib.h> |
21 | #include <termios.h> |
22 | |
23 | /* Use this variable to remember original terminal attributes. */ |
24 | |
25 | struct termios saved_attributes; |
26 | |
27 | void |
28 | reset_input_mode (void) |
29 | { |
30 | tcsetattr (STDIN_FILENO, TCSANOW, &saved_attributes); |
31 | } |
32 | |
33 | void |
34 | set_input_mode (void) |
35 | { |
36 | struct termios tattr; |
37 | |
38 | /* Make sure stdin is a terminal. */ |
39 | if (!isatty (STDIN_FILENO)) |
40 | { |
41 | fprintf (stderr, "Not a terminal.\n" ); |
42 | exit (EXIT_FAILURE); |
43 | } |
44 | |
45 | /* Save the terminal attributes so we can restore them later. */ |
46 | tcgetattr (STDIN_FILENO, termios_p: &saved_attributes); |
47 | atexit (func: reset_input_mode); |
48 | |
49 | /*@group*/ |
50 | /* Set the funny terminal modes. */ |
51 | tcgetattr (STDIN_FILENO, termios_p: &tattr); |
52 | tattr.c_lflag &= ~(ICANON|ECHO); /* Clear ICANON and ECHO. */ |
53 | tattr.c_cc[VMIN] = 1; |
54 | tattr.c_cc[VTIME] = 0; |
55 | tcsetattr (STDIN_FILENO, TCSAFLUSH, &tattr); |
56 | } |
57 | /*@end group*/ |
58 | |
59 | int |
60 | main (void) |
61 | { |
62 | char c; |
63 | |
64 | set_input_mode (); |
65 | |
66 | while (1) |
67 | { |
68 | read (STDIN_FILENO, &c, 1); |
69 | if (c == '\004') /* @kbd{C-d} */ |
70 | break; |
71 | else |
72 | write (STDOUT_FILENO, &c, 1); |
73 | } |
74 | |
75 | return EXIT_SUCCESS; |
76 | } |
77 | |