fuNote/kilo.c

434 lines
8.8 KiB
C
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/*** includes ***/
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#define _DEFAULT_SOURCE
#define _BSD_SOURCE
#define _GNU_SOURCE
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#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
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#include <sys/types.h>
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#include <termios.h>
#include <unistd.h>
/*** defines ***/
#define KILO_VERSION "0.0.1"
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#define KILO_TAB_STOP 8
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#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
};
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/*** data ***/
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typedef struct erow {
int size;
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int rsize;
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char *chars;
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char *render;
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} erow;
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struct editorConfig {
int cx, cy;
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int rowoff;
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int coloff;
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int screenrows;
int screencols;
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int numrows;
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erow *row;
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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 | ISIG);
raw.c_cc[VMIN] = 0;
raw.c_cc[VTIME] = 1;
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1)
die("tcsetattr");
}
int editorReadKey() {
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int nread;
char c;
while ((nread = read(STDIN_FILENO, &c, 1)) != 1) {
if (nread == -1 && errno != EAGAIN) die("read");
}
// Process escape sequences
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;
}
}
} else if (seq[0] == '0') {
switch (seq[1]) {
case 'H': return HOME_KEY;
case 'F': return END_KEY;
}
}
return '\x1b';
} else {
return c;
}
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}
int getCursorPosition(int *rows, int *cols) {
char buf[32];
unsigned int i = 0;
if (write(STDOUT_FILENO, "\x1b[6n", 4) != 4) // CPR (custor position report)
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) {
// Move cursor to the lower right as a fallback if TIOCGWINSZ does
// not work. We count the columns and rows then by hand.
if (write(STDOUT_FILENO, "\x1b[999C\x1b[999B", 12) != 12)
return -1;
return getCursorPosition(rows, cols);
return -1;
} else {
*cols = ws.ws_col;
*rows = ws.ws_row;
return 0;
}
}
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/*** row operations ***/
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void editorUpdateRow(erow *row) {
int tabs = 0;
int j;
for (j=0; j<row->size; j++) {
if (row->chars[j] == '\t') tabs++;
}
free(row->render);
row->render = malloc(row->size + tabs*(KILO_TAB_STOP-1) + 1);
int idx = 0;
for (j=0; j<row->size; j++) {
if (row->chars[j] == '\t') {
row->render[idx++] = ' ';
while (idx%KILO_TAB_STOP != 0) row->render[idx++] = ' ';
} else {
row->render[idx++] = row->chars[j];
}
}
row->render[idx] = '\0';
row->rsize = idx;
}
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void editorAppendRow(char *s, size_t len) {
E.row = realloc(E.row, sizeof(erow) * (E.numrows +1));
int at = E.numrows;
E.row[at].size = len;
E.row[at].chars = malloc(len + 1);
memcpy(E.row[at].chars, s, len);
E.row[at].chars[len] = '\0';
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E.row[at].rsize = 0;
E.row[at].render = NULL;
editorUpdateRow(&E.row[at]);
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E.numrows++;
}
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/*** file i/o ***/
void editorOpen(char *filename) {
FILE *fp = fopen(filename, "r");
if (!fp) die("fopen");
char *line = NULL;
size_t linecap = 0;
ssize_t linelen;
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while ((linelen = getline(&line, &linecap, fp)) != -1) {
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while (linelen > 0 && (line[linelen - 1] == '\n' ||
line[linelen - 1] == '\r'))
linelen--;
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editorAppendRow(line, linelen);
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}
free(line);
fclose(fp);
}
/*** append buffer ***/
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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 ***/
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void editorScroll() {
if (E.cy < E.rowoff) {
E.rowoff = E.cy;
}
if (E.cy >= E.rowoff + E.screenrows) {
E.rowoff = E.cy - E.screenrows + 1;
}
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if (E.cx < E.coloff) {
E.coloff = E.cx;
}
if (E.cx >= E.coloff + E.screencols) {
E.coloff = E.cx - E.screencols + 1;
}
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}
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void editorDrawRows(struct abuf *ab) {
int y;
for (y = 0; y < E.screenrows; y++) {
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int filerow = y + E.rowoff;
if (filerow >= E.numrows) {
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if (E.numrows == 0 && 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);
}
} else {
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int len = E.row[filerow].rsize - E.coloff;
if (len < 0) len = 0;
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if (len > E.screencols) len = E.screencols;
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abAppend(ab, &E.row[filerow].render[E.coloff], len);
}
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abAppend(ab, "\x1b[K", 3); // Erase one line
if (y < E.screenrows - 1) {
abAppend(ab, "\r\n", 2);
}
}
}
void editorRefreshScreen() {
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editorScroll();
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struct abuf ab = ABUF_INIT;
abAppend(&ab, "\x1b[?25l", 6); // Hide cursor
abAppend(&ab, "\x1b[H", 3); // CUP (cursor position)
editorDrawRows(&ab);
// Update cursor position
char buf[32];
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snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cy - E.rowoff) + 1, (E.cx - E.coloff) + 1);
abAppend(&ab, buf, strlen(buf));
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abAppend(&ab, "\x1b[?25h", 6); // Show cursor
write(STDOUT_FILENO, ab.b, ab.len);
abFree(&ab);
}
/*** input ***/
void editorMoveCursor(int key) {
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erow *row = (E.cy >= E.numrows) ? NULL : &E.row[E.cy];
switch (key) {
case ARROW_LEFT:
if (E.cx != 0) {
E.cx--;
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} else if (E.cy > 0) {
E.cy--;
E.cx = E.row[E.cy].size;
}
break;
case ARROW_RIGHT:
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if (row && E.cx < row->size) {
E.cx++;
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} else if (row && E.cx == row->size) {
E.cy++;
E.cx = 0;
}
break;
case ARROW_UP:
if (E.cy != 0) {
E.cy--;
}
break;
case ARROW_DOWN:
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if (E.cy < E.numrows) {
E.cy++;
}
break;
}
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row = (E.cy >= E.numrows) ? NULL : &E.row[E.cy];
int rowlen = row ? row->size : 0;
if (E.cx > rowlen) {
E.cx = rowlen;
}
}
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void editorProcessKeypress() {
int c = editorReadKey(); // Blocking!
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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;
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}
}
/*** init ***/
void initEditor() {
E.cx = 0;
E.cy = 0;
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E.rowoff = 0;
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E.coloff = 0;
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E.numrows = 0;
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E.row = NULL;
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if (getWindowSize(&E.screenrows, &E.screencols) == -1)
die("getWindowSize");
}
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int main(int argc, char *argv[]) {
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enableRawMode();
initEditor();
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if (argc >= 2) {
editorOpen(argv[1]);
}
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while (1) {
editorRefreshScreen();
editorProcessKeypress();
}
return 0;
}