Exmaple usage:
<< copy test.txt test/test.txt >>
./fsexec {uuid} WyJjb3B5IiwidGVzdC50eHQiLCJmb2xkZXIvdGVzdC50eHQiXQ==

<< copy_folder test/ target/test/ >>
./fsexec {uuid} WyJjb3B5X2ZvbGRlciIsInRlc3QvIiwidGFyZ2V0L3Rlc3QvIl0=