splitting things out

ke/Makefile

@@ -1,5 +1,5 @@
 BIN :=		ke
-OBJS :=		main.o
+OBJS :=		main.o terminal.o util.o
 
 LDFLAGS :=	-static
 CFLAGS :=	-pedantic -Wall -Werror -Wextra -O2 -std=c99
@@ -16,6 +16,7 @@ clean:
 
 .PHONY: run
 run: $(BIN)
+	reset
 	./$(BIN)
 
 %.o: %.c

ke/main.c

@@ -1,68 +1,62 @@
 #include <ctype.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <termios.h>
 #include <unistd.h>
 
-
-/* entry_term contains a snapshot of the termios settings at startup. */
-struct termios	entry_term;
+#include "terminal.h"
+#include "util.h"
 
 
-/*
- * A text editor needs the terminal to be in raw mode; but the default
- * is to be in canonical (cooked) mode, which is a buffered input mode.
- */
-
-static void
-enable_termraw()
+void
+loop()
 {
-	struct termios	raw;
-
-	/* Read the current terminal parameters for standard input. */
-	tcgetattr(STDIN_FILENO, &raw);
+	char	c;
+	int	command = 0;
 
+	while (1) {
+		c = '\0';
 		/*
-	 * Turn off the local ECHO mode, which we need to do in raw mode
-	 * because what gets displayed is going to need extra control.
-	 *
-	 * NOTE(kyle): look into cfmakeraw, which will require
-	 * snapshotting.
+		 * 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.
 		 */
-	raw.c_lflag &= ~(ECHO|ICANON);
-
-	/*
-	 * Now write the terminal parameters to the current terminal,
-	 * after flushing any waiting input out.
-	 */
-	tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw);
+		if ((read(STDIN_FILENO, &c, 1) == -1)) {
+			die("failed to read from the terminal");
 		}
 
+		if (c == 0x00) {
+			continue;
+		}
 
-static void
-disable_termraw()
-{
-	tcsetattr(STDIN_FILENO, TCSAFLUSH, &entry_term);
+		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);
+		}
+	}
 }
 
 
 int
 main()
 {
-	char	c;
-
-	/* prepare the terminal */
-	tcgetattr(STDIN_FILENO, &entry_term);
-	atexit(disable_termraw);
-	enable_termraw();
-
-	while (read(STDIN_FILENO, &c, 1) == 1 && c != 'q') {
-		if (iscntrl(c)) {
-			printf("%02x\n", c);
-		} else {
-			printf("%02x ('%c')\n", c, c);
-		}
-	}
+	setup_terminal();
+	loop();
 
 	return 0;
 }

ke/terminal.c

@@ -0,0 +1,70 @@
+#include <stdlib.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "util.h"
+
+
+static struct termios	entry_term;
+
+
+/*
+ * A text editor needs the terminal to be in raw mode; but the default
+ * is to be in canonical (cooked) mode, which is a buffered input mode.
+ */
+
+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");
+	}
+
+	/*
+	 * Put the terminal into raw mode.
+	 */
+	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");
+	}
+}
+
+
+static void
+disable_termraw()
+{
+	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &entry_term) == -1) {
+		die("couldn't disable terminal raw mode");
+	}
+}
+
+
+void
+setup_terminal()
+{
+	if (tcgetattr(STDIN_FILENO, &entry_term) == -1) {
+		die("can't snapshot terminal settings");
+	}
+	atexit(disable_termraw);
+	enable_termraw();
+}

ke/terminal.h

@@ -0,0 +1,8 @@
+#ifndef KE_TERMINAL_H
+#define KE_TERMINAL_H
+
+
+void	setup_terminal();
+
+
+#endif /* KE_TERMINAL_H */

ke/util.c

@@ -0,0 +1,10 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+
+void
+die(const char *s)
+{
+	perror(s);
+	exit(1);
+}

ke/util.h

@@ -0,0 +1,8 @@
+#ifndef KE_UTIL_H
+#define KE_UTIL_H
+
+
+void	die(const char *s);
+
+
+#endif /* KE_UTIL_H */