PHP | get_headers() Function

The get_headers() function in PHP is used to fetch all the headers sent by the server in the response of an HTTP request.

Syntax:

get_headers( $url, $format, $context )

Parameters: This function accepts three parameters as mentioned above and described below:

• $url: It is a mandatory parameter of type string. It defines the target URL.
• $format: It is an optional parameter of type int. If its value is set to non-zero it will return an associative array otherwise indexed array.
• $context: It holds the valid resource context created by stream_context_create() function.

Example 1: In this example, value of optional parameter $format is not assigned.

<?php

// Target URL
$url = "https://www.geeksforgeeks.org";

// Fetching headers
$headers = get_headers($url);

// Printing headers
print_r($headers);
?>

Output:

Array (
     [0] => HTTP/1.1 200 OK 
     [1] => Content-Type: text/html; charset=UTF-8 
     [2] => Connection: close 
     [3] => Date: Sun, 19 May 2019 08:31:29 GMT 
     [4] => Server: Apache 
     [5] => Strict-Transport-Security: max-age=3600; includeSubDomains 
     [6] => Cache-Control: s-maxage=21600, max-age=3, must-revalidate 
     [7] => Access-Control-Allow-Credentials: true 
     [8] => X-Frame-Options: DENY 
     [9] => X-Content-Type-Options: nosniff 
     [10] => Vary: Accept-Encoding, Cookie 
     [11] => X-Cache: Miss from cloudfront 
     [12] => Via: 1.1 aa0bb866c09b4e243eb9a97bcdb7fe32.cloudfront.net (CloudFront) 
     [13] => X-Amz-Cf-Id: QAOIIj4eBsrX0hyZ-UHjOtqA2dQePcLbEUZJ3KRohjsSPfcrcAFaiQ== 
) 

Example 2: In this example, value of optional parameter $format is set to non-zero.

<?php

// Target URL
$url = "https://www.geeksforgeeks.org";

// Fetching headers
$headers = get_headers($url, 1);

// Printing headers
print_r($headers);
?>

Output:

Array ( 
        [0] => HTTP/1.1 200 OK 
        [Content-Type] => text/html; charset=UTF-8 
        [Connection] => close 
        [Date] => Sun, 19 May 2019 08:35:47 GMT 
        [Server] => Apache 
        [Strict-Transport-Security] => max-age=3600; includeSubDomains 
        [Cache-Control] => s-maxage=21600, max-age=3, must-revalidate 
        [Access-Control-Allow-Credentials] => true 
        [X-Frame-Options] => DENY 
        [X-Content-Type-Options] => nosniff 
        [Vary] => Accept-Encoding, Cookie 
        [X-Cache] => Miss from cloudfront 
        [Via] => 1.1 95d17b4d563934eb90636ad03f8f524e.cloudfront.net (CloudFront) 
        [X-Amz-Cf-Id] => se3QRyaWDeuHI3GrisMzAr4FJBamqMtbUNzhTPqAJhBoQZbWvy3UPw== 
)