Implement exec.

Change-Id: I20329bc9b378479d745b498d6a00eca0872cd5ab
diff --git a/init/init_parser.h b/init/init_parser.h
index 0047da7..6348607 100644
--- a/init/init_parser.h
+++ b/init/init_parser.h
@@ -20,6 +20,7 @@
 #define INIT_PARSER_MAXARGS 64
 
 struct action;
+struct service;
 
 struct action *action_remove_queue_head(void);
 void action_add_queue_tail(struct action *act);
@@ -33,4 +34,6 @@
 int init_parse_config_file(const char *fn);
 int expand_props(char *dst, const char *src, int len);
 
+service* make_exec_oneshot_service(int argc, char** argv);
+
 #endif