Need help with a PHP Curl Post

I am working with an API that is asking me to do a http post to their server which has a tab-delimited batch file in the message-body.

I am currently using curl to handle the HTTP Post but I am not sure how I would add a file to the message body?

Anyone able to help?

 

Like this:

function execURL($url, $data = NULL){
        $postlen = count($data);
        foreach($data as $key=>$value) { $fields .= $key.'='.$value.'&'; }
        rtrim($fields,'&');
        $ch = curl_init();
        $timeout = 10;
        curl_setopt($ch,CURLOPT_URL,$url);
        curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
        curl_setopt($ch,CURLOPT_CONNECTTIMEOUT,$timeout);
        curl_setopt($ch,CURLOPT_POST,$postlen);
        curl_setopt($ch,CURLOPT_POSTFIELDS,$fields);
        $response = curl_exec($ch);
        curl_close($ch);
        return $response;
    }

PHP:

$data being thearray of data you want to post.
If you have 3 variables lets say - id, status and msg
It should be -
$data = array('id'=>$id, 'status'=>$status, 'msg'=>$msg);