reorganising and screen clearing and whatnot

.hgignore

@@ -1 +1,2 @@
 .o$
+ke/ke

ke/Makefile

@@ -1,5 +1,9 @@
 BIN :=		ke
-OBJS :=		main.o terminal.o util.o
+OBJS :=		main.o		\
+		display.o	\
+		keys.o		\
+		terminal.o	\
+		util.o
 
 LDFLAGS :=	-static
 CFLAGS :=	-pedantic -Wall -Werror -Wextra -O2 -std=c99

ke/main.c

@@ -5,6 +5,8 @@
 #include <termios.h>
 #include <unistd.h>
 
+#include "display.h"
+#include "keys.h"
 #include "terminal.h"
 #include "util.h"
 
@@ -12,42 +14,8 @@
 void
 loop()
 {
-	char	c;
-	int	command = 0;
-
 	while (1) {
-		c = '\0';
-		/*
-		 * Note that Cygwin, apparently, will treat a read time-
-		 * out as an error with errno == EAGAIN. I don't really
-		 * have any interest in supporting code for Cygwin.
-		 */
-		if ((read(STDIN_FILENO, &c, 1) == -1)) {
-			die("failed to read from the terminal");
-		}
-
-		if (c == 0x00) {
-			continue;
-		}
-
-		if (command && ((c == 'q') || (c == 0x11))) {
-			break;
-		}
-
-		if (c == 0x0b) {
-			if (!command) {
-				command = 1;
-				continue;
-			}
-		} else {
-			command = 0;
-		}
-
-		if (iscntrl(c)) {
-			printf("%02x\r\n", c);
-		} else {
-			printf("%02x ('%c')\r\n", c, c);
-		}
+		process_keypress();
 	}
 }
 
@@ -56,6 +24,8 @@ int
 main()
 {
 	setup_terminal();
+
+	display_clear();
 	loop();
 
 	return 0;

ke/notes.txt

@@ -0,0 +1,87 @@
+static void
+enable_termraw()
+{
+	struct termios	raw;
+
+	/* Read the current terminal parameters for standard input. */
+	if (tcgetattr(STDIN_FILENO, &raw) == -1) {
+		die("tcgetattr while enabling raw mode");
+	}
+
+	/*
+	 * Turn off software flow control. IXON: disable flow control,
+	 * so named because XON and XOFF :)
+	 *
+	 * ICRNL: Don't interpret carriage returns as newlines.
+	 *
+	 * raw.c_iflag &= ~(ICRNL|IXON|BRKINT|INPCK|ISTRIP);
+	 */
+
+	/*
+	 * Turn off the terminal's conversion of newlines -> carriage
+	 * return + newline.
+	 *
+	 * raw.c_oflag &= ~(OPOST);
+	 */
+
+	/*
+	 * Turn off the local ECHO mode, which we need to do in raw mode
+	 * because what gets displayed is going to need extra control.
+	 *
+	 * ICANON: Turn off canonical mode.
+	 *
+	 * ISIG: Turn off SIGINT / SIGSTP processing.
+	 *
+	 * IEXTEN: turn off ^v processing.
+	 *
+	 * NOTE(kyle): look into cfmakeraw, which will require
+	 * snapshotting. However, this skips all the notes about what
+	 * it takes to put the terminal in raw mode.
+	 *
+	 * raw.c_lflag &= ~(ECHO|ICANON|ISIG|IEXTEN);
+	 */
+
+	/*
+	 * The following are probably not really needed on modern
+	 * terminals, but it's fashionable to do as much.
+	 *
+	 * BRKINT: break conditions trigger SIGINT.
+	 *
+	 * INPCK: parity checking, which might be useful over serial
+	 * terminals?
+	 *
+	 * ISTRIP strips the high bit.
+	 *
+	 * CS: set character size to 8-bit.
+	 * raw.c_iflag &= ~(BRKINT | INPCK | ISTRIP);
+	 *
+	 * NOTE(kyle): I had this set here, but then it turns out
+	 * that it fuckled my terminal.
+	 * raw.c_cflag |= CS8;
+	 */
+
+	/*
+	 * Switched over to cfmakeraw.
+	 */
+	cfmakeraw(&raw);
+
+	/*
+	 * Set timeout for read(2).
+	 *
+	 * VMIN: what is the minimum number of bytes required for read
+	 * to return?
+	 *
+	 * VTIME: max time before read(2) returns in hundreds of milli-
+	 * seconds.
+	 */
+	raw.c_cc[VMIN] = 0;
+	raw.c_cc[VTIME] = 1;
+
+	/*
+	 * Now write the terminal parameters to the current terminal,
+	 * after flushing any waiting input out.
+	 */
+	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1) {
+		die("tcsetattr while enabling raw mode");
+	}
+}

ke/terminal.c

@@ -5,6 +5,9 @@
 #include "util.h"
 
 
+#define ESCSEQ		"\x1b["
+
+
 static struct termios	entry_term;
 
 
@@ -68,3 +71,11 @@ setup_terminal()
 	atexit(disable_termraw);
 	enable_termraw();
 }
+
+
+void
+display_clear()
+{
+	write(STDOUT_FILENO, ESCSEQ "2J", 4);
+	write(STDOUT_FILENO, ESCSEQ "H", 3);
+}

ke/terminal.h

@@ -3,6 +3,7 @@
 
 
 void	setup_terminal();
+void	display_clear();
 
 
 #endif /* KE_TERMINAL_H */

ke/util.c

@@ -5,6 +5,13 @@
 void
 die(const char *s)
 {
+	/*
+	 * NOTE(kyle): this is a duplication of the code in display.c
+	 * but I would like to be able to import these files from there.
+	 */
+	write(STDOUT_FILENO, "\x1b[2J", 4);
+	write(STDOUT_FILENO, "\x1b[H", 3);
+	
 	perror(s);
 	exit(1);
 }