+/*
+ * Do the "twrch" command. Returned value is 0 on success, -1 on failure
+ * (processing or arguments), or a non-zero exit code. Command-line
+ * arguments start _after_ the command name.
+ */
+int do_twrch(int argc, char *argv[]);
+
+/*
+ * Do the "impl" command. Returned value is 0 on success, -1 on failure.
+ * Command-line arguments start _after_ the command name.
+ */
+int do_impl(int argc, char *argv[]);
+