How can network restrictions, such as firewalls or blocking mechanisms, impact the ability to download images from URLs using PHP functions like copy or file_get_contents?

Network restrictions like firewalls or blocking mechanisms can prevent PHP functions like copy or file_get_contents from accessing URLs to download images. To bypass these restrictions, you can use cURL, which allows you to set custom headers and options to mimic a browser request. By setting user-agent headers and following redirects, you can successfully download images from URLs even with network restrictions in place.

$ch = curl_init();
$url = "https://example.com/image.jpg";
$output_file = "image.jpg";

curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3');
$data = curl_exec($ch);

file_put_contents($output_file, $data);

curl_close($ch);