+file
+open_tty(string name)
+{
+ int i = 0;
+ for (;;) {
+ try {
+ return open (name, "r+");
+ } catch open_error(string error, File::error_type error, string name) {
+ if (error == File::error_type.BUSY) {
+ if (i < 30) {
+ printf ("waiting for %s to be usable\n", name);
+ sleep(2000);
+ continue;
+ }
+ } else {
+ printf ("%s: %s\n", name, error);
+ exit(1);
+ }
+ }
+ }
+}
+