Added register decl, re-arranged some code

modules/src/system/break.c

@@ -13,7 +13,7 @@ sys_break(incr)
 	int incr;
 {
 	char *sbrk();
-	char *brk = sbrk(incr);
+	register char *brk = sbrk(incr);
 
 	if (brk == (char *) 0 || brk == (char *)-1)
 		return ILL_BREAK;

modules/src/system/open.c

@@ -14,42 +14,36 @@ sys_open(path, flag, filep)
 	int flag;
 	File **filep;
 {
-	register fd;
+	register int fd;
 	register File *fp;
-	int open_mode;
 	long lseek();
 
+	if ((fp = _get_entry()) == (File *)0)
+		return 0;
 	switch (flag) {
 	case OP_READ:
-		open_mode = 0;
+		if ((fd = open(path, 0)) < 0)
+			return 0;
 		break;
-	case OP_WRITE:
 	case OP_APPEND:
-		open_mode = 1;
+		if ((fd = open(path, 1)) < 0) {
+			if (access(path, 0) == 0)
+				return 0;
+		}
+		else {
+			if (lseek(fd, 0L, 2) < 0L) {
+				close(fd);
+				return 0;
+			}
+		}
+		/* Fall through */
+	case OP_WRITE:
+		if ((fd = creat(path, 0644)) < 0)
+			return 0;
 		break;
 	default:
 		return 0;
 	}
-	if ((fp = _get_entry()) == (File *)0)
-		return 0;
-	if (flag == OP_WRITE) {
-		if ((fd = creat(path, 0644)) < 0)
-			return 0;
-	}
-	else /* OP_READ or OP_APPEND */
-	if ((fd = open(path, open_mode)) < 0) {
-		if (flag == OP_READ || access(path, 0) == 0)
-			return 0;
-		/* now: flag == OP_APPEND */
-		if ((fd = creat(path, 0644)) < 0)
-			return 0;
-	}
-	else {
-		if (flag == OP_APPEND && (lseek(fd, 0L, 2) < 0L)) {
-			close(fd);
-			return 0;
-		}
-	}
 	fp->o_flags = flag;
 	fp->o_fd = fd;
 	*filep = fp;