Converts a string to an octal and hexadecimal escape sequence.
Escape sequence type:

Sometimes you need to change the code so that it is difficult to understand what it does. For example, you are a web developer, hand over a project to a customer, but are afraid that he may not pay. Then you can embed code on the site, which, for example, will give you access to create / modify / delete files on the client's server. But this code needs to be masked somehow. For such purposes, using the Hex-Oct encoder, you can convert some pieces of code to 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!".