Hex-Oct-encode

Sometimes you need to change the code so that it's difficult to understand what it does. For example, if you are a web developer delivering a project to a client but are afraid that they might not pay, you can embed code on the site that, for example, gives you access to create/modify/delete files on the client's server. But this code needs to be disguised. For such purposes, with the help of the Hex-Oct-encoder, you can convert some pieces of code into an escape sequence.

For example, $_SERVER["DOCUMENT_ROOT"] can be converted to $_SERVER["\104\117\103\x55\115\x45\116\124\x5f\x52\x4f\x4f\124"] and it will be the same.

Here's a more interesting example:
$a = "\143\162\x65\141\164\145\137\146\x75\156\x63\164\x69\x6f\156";
$a('$c', "\x65\143\x68\x6f\x20\x24\143\x3b")("\x68\x65\x6c\x6c\x6f\40\167\157\x72\x6c\x64\x21");
This code will display "hello world!" on the page.