1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
/*
* Terminal Text Editor
* Copyright (C) 2022 Johnny Richard
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include <ctype.h>
#include <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <unistd.h>
#define CTRL_KEY(k) ((k) & 0x1F)
typedef struct editor_config {
int screen_rows;
int screen_cols;
struct termios orig_termios;
} editor_config_t;
editor_config_t E;
void editor_init(editor_config_t *ec);
char editor_read_key();
int get_cursor_position(int *rows, int *cols);
int get_window_size(int *rows, int *cols);
void editor_process_key();
void editor_draw_rows(editor_config_t *ec);
void editor_clear_screen();
void editor_refresh_screen(editor_config_t *ec);
void disable_raw_mode();
void enable_raw_mode();
void die(const char *s);
int
main()
{
enable_raw_mode();
editor_init(&E);
while (true) {
editor_refresh_screen(&E);
editor_process_key();
}
return EXIT_SUCCESS;
}
void
editor_init(editor_config_t *ec)
{
if (get_window_size(&ec->screen_rows, &ec->screen_rows) == -1) {
die("get_window_size");
}
}
char
editor_read_key()
{
int nread;
char c;
while ((nread = read(STDIN_FILENO, &c, 1)) != 1) {
if (nread == -1 && errno != EAGAIN) {
die("read");
}
}
return c;
}
int
get_cursor_position(int *rows, int *cols)
{
char buf[32];
uint32_t i = 0;
if (write(STDIN_FILENO, "\x1b[6n", 4) != 4) {
return -1;
}
while (i < sizeof(buf) - 1) {
if (read(STDIN_FILENO, &buf[i], 1) != 1) {
break;
}
if (buf[i] == 'R') {
break;
}
i++;
}
buf[i] = '\0';
if (buf[0] != '\x1b' || buf[1] != '[') {
return -1;
}
if (sscanf(&buf[2], "%d;%d", rows, cols) != 2) {
return -1;
}
return 0;
}
int
get_window_size(int *rows, int *cols)
{
struct winsize ws;
if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0) {
if (write(STDIN_FILENO, "\x1b[999C\x1b[999B", 12) != 12) {
return -1;
}
return get_cursor_position(rows, cols);
}
*cols = ws.ws_col;
*rows = ws.ws_row;
return 0;
}
void
editor_process_key()
{
char c = editor_read_key();
switch (c) {
case CTRL_KEY('q'):
editor_clear_screen();
exit(EXIT_SUCCESS);
break;
}
}
void
editor_clear_screen()
{
write(STDOUT_FILENO, "\x1b[2J", 4);
write(STDOUT_FILENO, "\x1b[H", 3);
}
void
editor_draw_rows(editor_config_t *ec)
{
for (int y = 0; y < ec->screen_rows; ++y) {
write(STDOUT_FILENO, "~", 1);
if (y < ec->screen_rows - 1) {
write(STDOUT_FILENO, "\r\n", 2);
}
}
}
void
editor_refresh_screen(editor_config_t *ec)
{
editor_clear_screen();
editor_draw_rows(ec);
write(STDOUT_FILENO, "\x1b[H", 3);
}
void
disable_raw_mode()
{
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &E.orig_termios) == -1) {
die("tcsetattr");
}
}
void
enable_raw_mode()
{
if (tcgetattr(STDIN_FILENO, &E.orig_termios) == -1) {
die("tcgetattr");
}
atexit(disable_raw_mode);
struct termios raw = E.orig_termios;
raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
raw.c_oflag &= ~(OPOST);
raw.c_cflag &= ~(CS8);
raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
raw.c_cc[VMIN] = 0;
raw.c_cc[VTIME] = 1;
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1) {
die("tcsetattr");
}
}
void
die(const char *s)
{
editor_clear_screen();
perror(s);
exit(EXIT_FAILURE);
}
|
