displays rowq and getting terminal size

Makefile

@@ -14,6 +14,7 @@ build: main.c main.h
 	if [ ! -d beluga-output ]; then mkdir beluga-output; fi
 	if [ ! -d beluga-output/build ]; then mkdir beluga-output/build; fi
 	$(CC) main.c -o $(BELUGA_OUTPUT)/$(BUILD_DIR)/beluga $(BUILD_FLAGS)
+	doxygen
 
 DEBUG_DIR=debug
 
@@ -26,5 +27,6 @@ debug:  main.c main.h
 
 clean:
 	rm -rf $(BELUGA_OUTPUT)
+	rm -rf doc/
 
 # end

main.c

@@ -6,17 +6,31 @@
  */
 
 #include "main.h"
+#include <asm-generic/ioctls.h>
+#include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/ioctl.h>
 #include <termios.h>
 #include <unistd.h>
 
 /* defines */
 #define CTRL_KEY(k) ((k) & 0x1f)
+#define CURSOR_TOP_LEFT "\x1b[H"
 
 /* data */
-struct termios orig_termios;
+/**
+ * \struct editorConfig
+ * \brief Containing our editor state.
+ */
+struct editorConfig {
+  int screenrows;
+  int screencols;
+  struct termios orig_termios;
+};
+
+struct editorConfig E;
 
 /* terminal */
 
@@ -32,18 +46,18 @@ void die(const char *s) {
 }
 
 void disableRawMode() {
-  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios) == -1) {
+  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &E.orig_termios) == -1) {
     die("tcsetattr");
   }
 }
 
 void enableRawMode() {
-  if (tcgetattr(STDIN_FILENO, &orig_termios) == -1) {
+  if (tcgetattr(STDIN_FILENO, &E.orig_termios) == -1) {
     die("tcgetattr");
   }
   atexit(disableRawMode);
 
-  struct termios raw = orig_termios;
+  struct termios raw = E.orig_termios;
   raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
   raw.c_oflag &= ~(OPOST);
   raw.c_cflag |= (CS8);
@@ -67,16 +81,86 @@ char editorReadKey() {
   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;
+    }
+    return getCursorPosition(rows, cols);
+  } else {
+    *cols = ws.ws_col;
+    *rows = ws.ws_row;
+    return 0;
+  }
+}
+
 /* output */
 
+/** \fn void wipeScreen()
+ * \brief Wipe the terminal screen and put the cursor on the top left corner.
+ * */
 void wipeScreen() {
   /* Clear the screen */
   write(STDOUT_FILENO, "\x1b[2J", 4);
   /* Put the cursor at the top left corner */
-  write(STDOUT_FILENO, "\x1b[H", 3);
+  write(STDOUT_FILENO, CURSOR_TOP_LEFT, 3);
+}
+
+/**
+ * \fn void editorDrawRows()
+ * \brief Draws left rows of the editor.
+ */
+void editorDrawRows() {
+  int y;
+  for (y = 0; y < E.screenrows; ++y) {
+    write(STDOUT_FILENO, "~\r\n", 3);
+  }
+}
+
+void editorRefreshScreen() {
+  wipeScreen();
+  editorDrawRows();
+
+  write(STDOUT_FILENO, CURSOR_TOP_LEFT, 3);
 }
 
 /* input */
+
+/**
+ * \fn void editorProcessKeypress()
+ * \brief Get the last key input and do the proper action.
+ */
 void editorProcessKeypress() {
   char c = editorReadKey();
 
@@ -90,12 +174,23 @@ void editorProcessKeypress() {
 
 /* init */
 
+/**
+ * \fn void initEditor()
+ * \brief Job's function is to initialize all the fields of editorConfig.
+ * */
+void initEditor() {
+  if (getWindowSize(&E.screenrows, &E.screencols) == -1) {
+    die("getWindowSize");
+  }
+}
+
 int main() {
 
   enableRawMode();
+  initEditor();
 
   while (1) {
-    wipeScreen();
+    editorRefreshScreen();
     editorProcessKeypress();
   }
   return 0;

main.h

@@ -9,6 +9,8 @@ char editorReadKey();
 
 /* output */
 void wipeScreen();
+void editorDrawRows();
+void editorRefreshScreen();
 
 /* input */
 void editorProcessKeypress();