如何通过curl在Codeigniter中使用Mailgun中的附件

sudo apt-get install php-curl

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Mailgun_lib {
    private $api_key = 'YOUR_MAILGUN_API_KEY';
    private $api_base_url = 'https://api.mailgun.net/v3/YOUR_DOMAIN_NAME';

    public function send_email_with_attachment($to, $subject, $message, $attachment_path) {
        $curl = curl_init();

        curl_setopt_array($curl, array(
            CURLOPT_URL => $this->api_base_url . '/messages',
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_ENCODING => '',
            CURLOPT_MAXREDIRS => 10,
            CURLOPT_TIMEOUT => 30,
            CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
            CURLOPT_CUSTOMREQUEST => 'POST',
            CURLOPT_POSTFIELDS => array(
                'from' => 'YOUR_SENDER_EMAIL',
                'to' => $to,
                'subject' => $subject,
                'text' => $message,
                'attachment' => curl_file_create($attachment_path)
            ),
            CURLOPT_HTTPHEADER => array(
                'Authorization: Basic ' . base64_encode('api:' . $this->api_key)
            ),
        ));

        $response = curl_exec($curl);
        $err = curl_error($curl);

        curl_close($curl);

        if ($err) {
            echo 'cURL Error #:' . $err;
        } else {
            echo $response;
        }
    }
}

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Email_controller extends CI_Controller {
    public function __construct() {
        parent::__construct();
        $this->load->library('mailgun_lib');
    }

    public function send_email() {
        $to = 'recipient@example.com';
        $subject = 'Test Email with Attachment';
        $message = 'This is a test email with attachment.';
        $attachment_path = '/path/to/attachment/file.pdf';

        $this->mailgun_lib->send_email_with_attachment($to, $subject, $message, $attachment_path);
    }
}