Percent character replaced in Codeigniter

Question

In Codeigniter I\'m sending a string using POST method as \"%100\" and it becomes \"0\". I believe this is because they\'re being treated as encode

Answer 1

I believe the problem here is nothing to do with CI or even PHP, but with your HTTP request.

Lets say I make a POST request that looks like this:

POST /path/to/file HTTP/1.1
Host: server.com
User-Agent: Bob the browser/1.0
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 25

name=Dave&percentage=%100

What you are probably expecting is for $_POST to look like this:

Array
    (
        [name] => Dave
        [percentage] => %100
    )

But, in fact PHP will (correctly) decode it as this:

Array
    (
        [name] => Dave
        [percentage] => 0
    )

This is because %10 is a valid url encoded string, and will be translated to the non-printable and in this context meaningless "Data Link Escape" character, ASCII 0x10.

In order to get the result you expect, the request needs to be like this:

POST /path/to/file HTTP/1.1
Host: server.com
User-Agent: Bob the browser/1.0
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 27

name=Dave&percentage=%25100

So the value you actually send in the POST body is %25100. This will be correctly decoded as %100.