First commit

.gitignore

@@ -0,0 +1,2 @@
+.idea
+kilo

Makefile

@@ -0,0 +1,2 @@
+kilo: kilo.c
+	$(CC) kilo.c -o kilo -Wall -Wextra -pedantic -std=c99

kilo.c

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+/*** includes ***/
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <termios.h>
+#include <unistd.h>
+
+/*** defines ***/
+
+#define KILO_VERSION "0.0.1"
+
+#define CTRL_KEY(k) ((k) & 0x1f)
+
+enum editorKey {
+	ARROW_LEFT = 1000,
+	ARROW_RIGHT,
+	ARROW_UP,
+	ARROW_DOWN,
+	DEL_KEY,
+	HOME_KEY,
+	END_KEY,
+	PAGE_UP,
+	PAGE_DOWN,
+};
+
+/*** data ***/
+
+struct editorConfig {
+	int cx, cy;
+	int screenrows;
+	int screencols;
+	struct termios orig_termios;
+};
+
+struct editorConfig E;
+
+/*** terminal ***/
+
+void die(const char *s)
+{
+	write(STDOUT_FILENO, "\x1b[2J", 4);
+	write(STDOUT_FILENO, "\x1b[H", 3);
+
+	perror(s);
+	exit(1);
+}
+
+void disableRawMode()
+{
+	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &E.orig_termios) == -1)
+	{
+		die("tcsetattr");
+	}
+}
+
+void enableRawMode()
+{
+	if (tcgetattr(STDIN_FILENO, &E.orig_termios) == -1) {
+		die("tcgetattr");
+	}
+	atexit(disableRawMode);
+
+	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");
+	}
+}
+
+int editorReadKey()
+{
+	int nread;
+	char c;
+	while ((nread = read(STDIN_FILENO, &c, 1)) != 1)
+	{
+		if (nread == -1 && errno != EAGAIN)
+		{
+			die("read");
+		}
+	}
+
+	if (c == '\x1b')
+	{
+		char seq[3];
+
+		if (read(STDIN_FILENO, &seq[0], 1) != 1)
+		{
+			return '\x1b';
+		}
+
+		if (read(STDIN_FILENO, &seq[1], 1) != 1)
+		{
+			return '\x1b';
+		}
+
+		if (seq[0] == '[')
+		{
+			if (seq[1] >= '0' && seq[1] <= 9)
+			{
+				if (read(STDIN_FILENO, &seq[2], 1) != 1)
+				{
+					return '\x1b';
+				}
+
+				if (seq[2] == '~')
+				{
+					switch (seq[1])
+					{
+						case '1': return HOME_KEY;
+						case '3': return DEL_KEY;
+						case '4': return END_KEY;
+						case '5': return PAGE_UP;
+						case '6': return PAGE_DOWN;
+						case '7': return HOME_KEY;
+						case '8': return END_KEY;
+					}
+				}
+			}
+			else
+			{
+				switch (seq[1])
+				{
+					case 'A': return ARROW_UP;
+					case 'B': return ARROW_DOWN;
+					case 'C': return ARROW_RIGHT;
+					case 'D': return ARROW_LEFT;
+					case 'H': return HOME_KEY;
+					case 'F': return END_KEY;
+				}
+			}
+
+		}
+		else if (seq[0] == 'O')
+		{
+			switch (seq[1])
+			{
+				case 'H': return HOME_KEY;
+				case 'F': return END_KEY;
+			}
+		}
+
+		return '\x1b';
+	}
+
+	return c;
+}
+
+int getCursorPosition(int *rows, int *cols)
+{
+	char buf[32];
+	unsigned int i = 0;
+
+	if (write(STDOUT_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 getWindowSize(int *rows, int *cols)
+{
+	struct winsize ws;
+
+	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0)
+	{
+		if (write(STDOUT_FILENO, "\x1b[999C\x1b[999B", 12) != 12)
+		{
+			return -1;
+		}
+		else
+		{
+			return getCursorPosition(rows, cols);
+		}
+	}
+
+	*cols = ws.ws_col;
+	*rows = ws.ws_row;
+
+	return 0;
+}
+
+/*** append buffer ***/
+
+struct abuf {
+	char *b;
+	int len;
+};
+
+#define ABUF_INIT {NULL, 0};
+
+void abAppend(struct abuf *ab, const char *s, int len)
+{
+	char *new = realloc(ab->b, ab->len + len);
+
+	if (new == NULL)
+	{
+		return;
+	}
+
+	memcpy(&new[ab->len], s, len);
+	ab->b = new;
+	ab->len += len;
+}
+
+void abFree(struct abuf *ab)
+{
+	free(ab->b);
+}
+
+/*** output ***/
+
+void editorDrawRows(struct abuf *ab)
+{
+	int y;
+	for (y = 0; y < E.screenrows; y++)
+	{
+		if (y == E.screenrows / 3)
+		{
+			char welcome[80];
+			int welcomelen = snprintf(welcome, sizeof(welcome),
+				"Kilo editor -- version %s", KILO_VERSION);
+
+			if (welcomelen > E.screencols)
+			{
+				welcomelen = E.screencols;
+			}
+
+			int padding = (E.screencols - welcomelen) / 2;
+			if (padding)
+			{
+				abAppend(ab, "~", 1);
+				padding--;
+			}
+
+			while (padding--)
+			{
+				abAppend(ab, " ", 1);
+			}
+
+			abAppend(ab, welcome, welcomelen);
+		}
+		else
+		{
+			abAppend(ab, "~", 1);
+		}
+
+		abAppend(ab, "\x1b[K", 3);
+		if (y < E.screenrows - 1)
+		{
+			abAppend(ab, "\r\n", 2);
+		}
+	}
+}
+
+void editorRefreshScreen()
+{
+	struct abuf ab = ABUF_INIT;
+
+	abAppend(&ab, "\x1b[?25l", 6);
+	abAppend(&ab, "\x1b[H", 3);
+
+	editorDrawRows(&ab);
+
+	char buf[32];
+	snprintf(buf, sizeof(buf), "\x1b[%d;%dH", E.cy + 1, E.cx + 1);
+	abAppend(&ab, buf, strlen(buf));
+
+	abAppend(&ab, "\x1b[?25h", 6);
+
+	write(STDOUT_FILENO, ab.b, ab.len);
+	abFree(&ab);
+}
+
+/*** input ***/
+
+void editorMoveCursor(int key)
+{
+	switch (key)
+	{
+		case ARROW_LEFT:
+			if (E.cx != 0)
+			{
+				E.cx--;
+			}
+		break;
+
+		case ARROW_RIGHT:
+			if (E.cx != E.screencols - 1)
+			{
+				E.cx++;
+			}
+		break;
+
+		case ARROW_UP:
+			if (E.cy != 0)
+			{
+				E.cy--;
+			}
+		break;
+
+		case ARROW_DOWN:
+			if (E.cy != E.screenrows - 1)
+			{
+				E.cy++;
+			}
+		break;
+	}
+}
+
+void editorProcessKeypress()
+{
+	int c = editorReadKey();
+
+	switch (c)
+	{
+		case CTRL_KEY('q'):
+			write(STDOUT_FILENO, "\x1b[2J", 4);
+			write(STDOUT_FILENO, "\x1b[H", 3);
+			exit(0);
+		break;
+
+		case HOME_KEY:
+			E.cx = 0;
+		break;
+
+		case END_KEY:
+			E.cx = E.screencols - 1;
+		break;
+
+		case PAGE_UP:
+		case PAGE_DOWN: {
+			int times = E.screenrows;
+			while (times--)
+			{
+				editorMoveCursor(c == PAGE_UP ? ARROW_UP : ARROW_DOWN);
+			}
+		}
+		break;
+
+		case ARROW_UP:
+		case ARROW_DOWN:
+		case ARROW_LEFT:
+		case ARROW_RIGHT:
+			editorMoveCursor(c);
+		break;
+	}
+}
+
+/*** init ***/
+
+void initEditor()
+{
+	E.cx = 0;
+	E.cy = 0;
+
+	if (getWindowSize(&E.screenrows, &E.screencols) == -1)
+	{
+		die("getWindowSize");
+	}
+}
+
+int main()
+{
+	enableRawMode();
+	initEditor();
+
+	while (1)
+	{
+		editorRefreshScreen();
+		editorProcessKeypress();
+	}
+	return 0;
+}
+