How can I recieve and treat data from a cURL call - php

Question

I have to send a json response from a cURL call.
The user send me a "test" variable to file.php.
On my php file, I use this code
$arr = array($arr = array('test' => 'ok'));
echo json_encode($arr);
And this for the cURL call
curl --request POST http://www.domain.com/WS/file.php -d '{ "test" : "12341234123412342" }'
Here is the answer
[{"test":null}]
What's the good way to get de POST variable and treat it in my php file?
Thanks
EDIT
Just in case, the problem comes from the cURL call. Here's the correct syntax:
curl -H "Content-Type: application/json" -X POST -d "{\"test\":\"12341234123412342\"}" http://www.domain.com/WS/file.php

Answer 1

Ur question is kinda confusing :)
so ur User sends u a variable in file.php
and u have to curl with that variable ?
why not just
curl --request POST http://www.domain.com/WS/file.php -d '{ "test" : "$_POST['USER_INPUT_VALUE']" }'
or am i missing something ?

Answer 2

Thanks for your help.
You're right, it might be confusing. I have to add some new details and give a better example.
The user execute that script in a file test_curl.php:
// test_curl.php
$url = "http://www.domain.com/WS/file.php";
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
$data = array(
'test' => '12345'
);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
$contents = curl_exec($ch);
echo $contents;
curl_close($ch);
Here's the file.php
// file.php
$arr = array($arr = array('test' => $_POST['test']));
echo json_encode($arr);
I recieve the POST variable and it works. Here's what $contents recieve in test_curl.php
{"test" => "12345"}
New fact, it works with test_curl.php. I've got the good answer but when do it in command line with that code...
curl --request POST http://www.domain.com/WS/file.php -d '{ "test" : "12345" }'
...I've got this answer:
[{"test":null}]
And finally, my question is why the response is null when I make my call in command line?

Answer 3

That won't work.
In your post data you are sending a json/application content type. Inside the server, you are expecting content from a variable called test, which should only exists in a normal form key valued body, which is not the case.
So, you need to json_decode directly the raw body of the post data content, then access the test key inside it, as such:
$raw_body = file_get_contents('php://input');
$json = json_decode($raw_body);
$arr = array($arr = array('test' => $json['test']);
echo json_encode($arr);