tutorials/kilo
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Timothy Warren 2019-08-16 16:32:29 -04:00
commit 727baa5069
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.gitignore vendored Normal file
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.idea
kilo

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Makefile Normal file
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kilo: kilo.c
$(CC) kilo.c -o kilo -Wall -Wextra -pedantic -std=c99

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kilo.c Normal file
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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;
}