How to Use Arrays in Curl Post Requests

How do I use arrays in cURL POST requests

You are just creating your array incorrectly. You could use http_build_query:

$fields = array(
            'username' => "annonymous",
            'api_key' => urlencode("1234"),
            'images' => array(
                 urlencode(base64_encode('image1')),
                 urlencode(base64_encode('image2'))
            )
        );
$fields_string = http_build_query($fields);

So, the entire code that you could use would be:

<?php
//extract data from the post
extract($_POST);

//set POST variables
$url = 'http://api.example.com/api';
$fields = array(
            'username' => "annonymous",
            'api_key' => urlencode("1234"),
            'images' => array(
                 urlencode(base64_encode('image1')),
                 urlencode(base64_encode('image2'))
            )
        );

//url-ify the data for the POST
$fields_string = http_build_query($fields);

//open connection
$ch = curl_init();

//set the url, number of POST vars, POST data
curl_setopt($ch,CURLOPT_URL, $url);
curl_setopt($ch,CURLOPT_POST, 1);
curl_setopt($ch,CURLOPT_POSTFIELDS, $fields_string);

//execute post
$result = curl_exec($ch);
echo $result;

//close connection
curl_close($ch);
?>

How to pass curl post request where there is an array in data?

The data payload is just JSON? Wouldn't you simply include the array as an element of the data object?

curl --digest --user abc -H 'Content-Type: application/json' --request POST -d ' {"url":"www.okta.com", "groups": ["g1", "g2"]}' url

How to post array within array with curl

Neither of form submission formats support nested (multi-dimensional) arrays. In other words you cannot send nested arrays in POST request as form-encoded data (CURL uses application/x-www-form-urlencoded format by default). Most likely you've misinterpreted API specs. Perhaps the API accept data in other format, for instance, JSON which allows any level of nesting.

Passing form array data in CURL

CURLOPT_POSTFIELDS => array(
    'first_name' => $_POST['user']['first_name'],
    'last_name' => $_POST['user']['last_name'],
    'conditions[]' => '1',
    'conditions[]' => '2',
    'conditions[]' => '3'
),

That conditions[] “syntax” works for form field names, PHP will then automatically create an array out of those parameters.

It does not work in code - you have just overwritten the key conditions[] three times here, so of course only the last value survives.

You simply want something like 'conditions[]' => ['1', '2', '3'] in that place.

Sending a multidimensional array using cURL and foreach in php

Thanks to This awesome reply I understood I must use $POST only.

sender:

<?php

function post_to_url($url, $data) {
    $post = curl_init();

    curl_setopt($post, CURLOPT_URL, $url);
    curl_setopt($post, CURLOPT_POSTFIELDS, http_build_query($data));
    curl_setopt($post, CURLOPT_RETURNTRANSFER, true);

    $result = curl_exec($post);
    curl_close($post);
}

if (isset($_POST['submit'])){

    $name = addslashes(strip_tags($_POST["name"]));
    $address = addslashes(strip_tags($_POST["address"]));
    $email = addslashes(strip_tags($_POST["email"]));
    $job = addslashes(strip_tags($_POST["job"]));

    $list = array (
        array('name', "$name"),
        array('address', "$address"),
        array('email', "$email"),
        array('job', "$job"),
        array(''),
        array('options', 'status', 'link','time', 'note','check' )
    );


    // Merge the 2 arrays together
    $final_array = array_merge($list, $_POST['prefs']);

    // Send through CURL
    post_to_url("http://192.168.10.10/receiver.php", $final_array);

    header("Location:index.php");
    exit;
}

?>

receiver:

<?php
$csv = fopen( "/home/user/file.csv", 'w+' );
foreach ($_POST as $fields) {
    fputcsv($csv, $fields, ";");
}
fclose($csv);
?>

And now it works.

how do i POST an empty array with curl in c?

Empty arrays don't really exist in URL-encoded parameters. When you send an array, it's sent as:

name[]=firstElement&name[]=secondElement&name[]=thirdElement

An empty array means you don't send any of these, but then there's no parameter at all.

It's the responsibility of the server code to handle the nonexisting parameter and treat it as an empty array.

When you write

curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "emptyArr[]");

it's being treated as

curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "emptyArr[]=");

so you're creating an array with one element whose value is an empty string.

You should simply leave out the parameter entirely, and the server should treat it as empty.

How can I post array field data via cURL?

You are doing concatenation over the array inside the foreach loop.

Your Array:

'fruit' => array($fruit)

And when doing a concatenation like below, you are getting Array as plain text inside the $value:

$fields_string .= $key.'='.$value.'&';

So ultimately you are posting: first_name=Joe&last_name=Jones&fruit=Array

My suggestion is to use http_build_query() and remove your manual post data building.

curl_setopt($ch,CURLOPT_POSTFIELDS, http_build_query($fields));