113 lines
2.1 KiB
C
113 lines
2.1 KiB
C
/*** includes ***/
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#include <ctype.h>
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <termios.h>
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#include <unistd.h>
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/*** defines ***/
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#define CTRL_KEY(k) ((k) & 0x1f)
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/*** data ***/
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struct termios orig_termios;
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/*** terminal ***/
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void die(const char* s) {
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// Clear the whole screen.
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write(STDOUT_FILENO, "\x1b[2J", 4);
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// Move cursor to top left.
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write(STDOUT_FILENO, "\x1b[H", 3);
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perror(s);
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exit(1);
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}
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void disableRawMode() {
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if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios) == -1)
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die("tcsetattr");
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}
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void enableRawMode() {
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if (tcgetattr(STDIN_FILENO, &orig_termios) == -1)
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die("tcgetattr");
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atexit(disableRawMode);
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struct termios raw = orig_termios;
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raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
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raw.c_oflag &= ~(OPOST);
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raw.c_cflag |= (CS8);
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raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
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// Sets timeouts for read()
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raw.c_cc[VMIN] = 0;
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raw.c_cc[VTIME] = 1;
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if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1)
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die("tcsetattr");
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}
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char editorReadKey() {
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int nread;
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char c;
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while ((nread = read(STDIN_FILENO, &c, 1)) != 1) {
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if (nread == -1 && errno != EAGAIN) {
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die("read");
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}
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}
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return c;
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}
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/*** output ***/
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void editorDrawRows() {
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for (int y = 0; y < 24; y++) {
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write(STDOUT_FILENO, "~\r\n", 3);
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}
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}
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void editorRefreshScreen() {
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// Clear the whole screen.
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write(STDOUT_FILENO, "\x1b[2J", 4);
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// Move cursor to top left.
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write(STDOUT_FILENO, "\x1b[H", 3);
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editorDrawRows();
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write(STDOUT_FILENO, "\x1b[H", 3);
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}
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/*** input ***/
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void editorProcessKeypress() {
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char c = editorReadKey();
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switch (c) {
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case CTRL_KEY('q'):
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// Clear the whole screen.
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write(STDOUT_FILENO, "\x1b[2J", 4);
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// Move cursor to top left.
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write(STDOUT_FILENO, "\x1b[H", 3);
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exit(0);
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break;
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}
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}
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/*** init ***/
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int main() {
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enableRawMode();
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while(1) {
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editorRefreshScreen();
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editorProcessKeypress();
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}
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return 0;
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}
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