PHP 7.0.6 Released

get_headers

(PHP 5, PHP 7)

get_headersFetches all the headers sent by the server in response to a HTTP request

Description

array get_headers ( string $url [, int $format = 0 ] )

get_headers() returns an array with the headers sent by the server in response to a HTTP request.

Parameters

url

The target URL.

format

If the optional format parameter is set to non-zero, get_headers() parses the response and sets the array's keys.

Return Values

Returns an indexed or associative array with the headers, or FALSE on failure.

Changelog

Version Description
5.1.3 This function now uses the default stream context, which can be set/changed with the stream_context_set_default() function.

Examples

Example #1 get_headers() example

<?php
$url 
'http://www.example.com';

print_r(get_headers($url));

print_r(get_headers($url1));
?>

The above example will output something similar to:

Array
(
    [0] => HTTP/1.1 200 OK
    [1] => Date: Sat, 29 May 2004 12:28:13 GMT
    [2] => Server: Apache/1.3.27 (Unix)  (Red-Hat/Linux)
    [3] => Last-Modified: Wed, 08 Jan 2003 23:11:55 GMT
    [4] => ETag: "3f80f-1b6-3e1cb03b"
    [5] => Accept-Ranges: bytes
    [6] => Content-Length: 438
    [7] => Connection: close
    [8] => Content-Type: text/html
)

Array
(
    [0] => HTTP/1.1 200 OK
    [Date] => Sat, 29 May 2004 12:28:14 GMT
    [Server] => Apache/1.3.27 (Unix)  (Red-Hat/Linux)
    [Last-Modified] => Wed, 08 Jan 2003 23:11:55 GMT
    [ETag] => "3f80f-1b6-3e1cb03b"
    [Accept-Ranges] => bytes
    [Content-Length] => 438
    [Connection] => close
    [Content-Type] => text/html
)

Example #2 get_headers() using HEAD example

<?php
// By default get_headers uses a GET request to fetch the headers. If you
// want to send a HEAD request instead, you can do so using a stream context:
stream_context_set_default(
    array(
        
'http' => array(
            
'method' => 'HEAD'
        
)
    )
);
$headers get_headers('http://example.com');
?>

See Also

User Contributed Notes

nick at innovaweb dot co dot uk
5 years ago
Seems like there are some people who are looking for only the 3-digit HTTP response code  - here is a quick and nasty solution:

<?php
function get_http_response_code($theURL) {
   
$headers = get_headers($theURL);
    return
substr($headers[0], 9, 3);
}
?>

How easy is that? Echo the function containing the URL you want to check the response code for, and voilà. Custom redirects, alternative for blocked is_file() or flie_exists() functions (like I seem to have on my servers) hence the cheap workaround. But hey - it works!

Pudding
Jim Greene
2 years ago
I know you're not supposed to reference other notes, but sincere props to Nick at Innovaweb's comment, for which I base this addition to his idea:

If you use that function, it will return a string, which is great if you are checking for only files that return 404, or 200, or whatnot.  If you cast the string value to an integer, you can perform mathematical comparison on it. 

For example:

<?php
function get_http_response_code($theURL) {
   
$headers = get_headers($theURL);
    return
substr($headers[0], 9, 3);
}

if(
intval(get_http_response_code('filename.jpg')) < 400){
// File exists, huzzah!
}
?>

Rule of thumb is if the response is less than 400, then the file's there, even if it doesn't return 200.
damolp at hotmail dot com
4 years ago
I found that this function is the slowest in obtaining the headers of a page probably because it uses a GET request rather then a HEAD request. Over 10,000,000 trials of obtaining the headers of a page from a server i found the following (results in seconds).

cURL: Mean: 0.584127946. Sigma: 0.050581736.
fsocketopen: Mean: 0.622114251. Sigma: 0.263170424.
get_headers: Mean: 0.90375551. Sigma: 0.273823419.

cURL was the fastest with fsocketopens being the second fastest. I noticed as well that fsocketopen had some outliers where as cURL did not.
Weboide
5 years ago
Note that get_headers **WILL follow redirections** (HTTP redirections). New headers will be appended to the array if $format=0. If $format=1 each redundant header will be an array of multiple values, one for each redirection.

For example:

<?php
$url
= 'http://google.com';
var_dump(get_headers($url,0));
/*array(18) {
  [0]=>  string(30) "HTTP/1.0 301 Moved Permanently"
  [1]=>  string(32) "Location: http://www.google.com/"
  [2]=>  string(38) "Content-Type: text/html; charset=UTF-8"
  [3]=>  string(35) "Date: Sun, 26 Sep 2010 00:59:50 GMT"
  [4]=>  string(38) "Expires: Tue, 26 Oct 2010 00:59:50 GMT"
  [5]=>  string(38) "Cache-Control: public, max-age=2592000"
....
  string(15) "HTTP/1.0 200 OK"
  [10]=>  string(35) "Date: Sun, 26 Sep 2010 00:59:51 GMT"
  [11]=>  string(11) "Expires: -1"
  [12]=>  string(33) "Cache-Control: private, max-age=0"
.....
}*/

/*===========================*/

var_dump(get_headers($url,1));
/*array(11) {
  [0]=>
  string(30) "HTTP/1.0 301 Moved Permanently"
  ["Location"]=>  string(22) "http://www.google.com/"
  ["Content-Type"]=>  array(2) {
    [0]=>    string(24) "text/html; charset=UTF-8"
    [1]=>    string(29) "text/html; charset=ISO-8859-1"
  }
  ["Date"]=>  array(2) {
    [0]=>    string(29) "Sun, 26 Sep 2010 01:03:39 GMT"
    [1]=>    string(29) "Sun, 26 Sep 2010 01:03:39 GMT"
  }
  ["Expires"]=>  array(2) {
    [0]=>    string(29) "Tue, 26 Oct 2010 01:03:39 GMT"
    [1]=>    string(2) "-1"
  }
  ["Cache-Control"]=>  array(2) {
    [0]=>    string(23) "public, max-age=2592000"
    [1]=>    string(18) "private, max-age=0"
  }
.....
}*/
?>
gabe at vtunnel dot com
7 years ago
In some cases, you don't want get_headers to follow redirects. For example, some of my servers can access a particular website, which sends a redirect header. The site it is redirected to, however, has me firewalled. I need to take the 302 redirected url, and do something to it to give me a new url that I *can* connect to.

The following will give you output similar to get_headers, except it has a timeout, and it doesn't follow redirects:

<?php
function get_headers_curl($url)
{
   
$ch = curl_init();

   
curl_setopt($ch, CURLOPT_URL,            $url);
   
curl_setopt($ch, CURLOPT_HEADER,         true);
   
curl_setopt($ch, CURLOPT_NOBODY,         true);
   
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
   
curl_setopt($ch, CURLOPT_TIMEOUT,        15);

   
$r = curl_exec($ch);
   
$r = split("\n", $r);
    return
$r;
}

If
you do want to follow redirects, you can do something like this:

$go = 1;
$i = 1;

while (
$go && $i < 6)
{
   
$headers = get_headers_curl($url);
   
$go = getNextLocation($headers);
    if (
$go)
    {
       
$url = modifyUrl($go);
    }
   
$i++;
}

function
getNextLocation($headers)
{
   
$array = $headers;
   
$count = count($array);

    for (
$i=0; $i < $count; $i++)
    {
        if (
strpos($array[$i], "ocation:"))
        {
               
$url = substr($array[$i], 10);
        }
    }
    if (
$url)
    {
        return
$url;
    }
    else
    {
        return
0;
    }
}
?>
pegasus at vaultwiki dot org
1 year ago
Note that get_headers should not be used against a URL that was gathered via user input. The timeout option in the stream context only affects the idle time between data in the stream. It does not affect connection time or the overall time of the request.

(Unfortunately, this is not mentioned in the docs for the timeout option, but has been discussed in a number of code discussions elsewhere, and I have done my own tests to confirm the conclusions of those discussions.)

Thus it is very easy for a user to give you a URL that acts like a Slowloris attack - feeding your get_headers function 1 header only often enough to avoid the stream timeout.

If you are publishing your code, even default_socket_timeout cannot be relied on to remedy this, because it is broken for the HTTPS protocol on many but the more recent versions of PHP: https://bugs.php.net/bug.php?id=41631

With get_headers accepting user input, it can be very easy for an attacker to make all of your PHP child processes become busy.

Instead, use cURL functions to get headers for a URL provided by the user and parse those headers manually, as CURLOPT_TIMEOUT applies to the entire request.
bobray at softville dot com
11 months ago
Testing the validity of a URL that is preceded by one or more server redirects is tricky. There will be more than one status code returned and all but the first will be redirect codes.

This function will return an integer containing the three digit status code of the last code returned, which is what you want.

    function getStatus($url) {
        $headers = @get_headers($url, true);
        $value = NULL;
        if ($headers === false) {
            return $headers;
        }
        foreach ($headers as $k => $v) {
            if (!is_int($k)) {
                continue;
            }
            $value = $v;
        }

        return (int) substr($value, strpos($value, ' ', 8) + 1, 3);
     }

If getHeaders() fails, PHP will throw an error. Test the return value for === false.
cees at cornelisdigitaal dot nl
1 year ago
@Jim Greene:

if the URL does not exist, it returns incomplete headers, making the substring default to rubbish.

The integer value of rubbish is always 0. So your lower than 400 does not always means it exists!
Kubo2
2 years ago
If you don't want to display Warning when get_headers() function fails, you can simply add at-sign (@) before it.

<?php

// in failure, Warning will be hidden and false returned
$withoutWarning = @get_headers("http://www.some-domain.com");

// in  failure, Warning displays and false will be returned, too
$withWarning = get_headers("http://www.some-domain.com");

// bool(false)
var_dump($withoutWarning);
// bool(false)
var_dump($withWarning);
?>
Anonymous
9 years ago
If you want to get headers that current PHP process is going to send back to browser, see headers_list()
php at hm2k dot org
6 years ago
<?php
/**
* Fetches all the real headers sent by the server in response to a HTTP request without redirects
*
* @link      http://php.net/function.get_headers
* @link      http://bugs.php.net/bug.php?id=50719
*/

function get_real_headers($url,$format=0,$follow_redirect=0) {
  if (!
$follow_redirect) {
   
//set new default options
   
$opts = array('http' =>
        array(
'max_redirects'=>1,'ignore_errors'=>1)
    );
   
stream_context_get_default($opts);
  }
 
//get headers
   
$headers=get_headers($url,$format);
   
//restore default options
 
if (isset($opts)) {
   
$opts = array('http' =>
        array(
'max_redirects'=>20,'ignore_errors'=>0)
    );
   
stream_context_get_default($opts);
  }
 
//return
   
return $headers;
}
?>
info at marc-gutt dot de
7 years ago
Should be the same than the original get_headers():

<?php
if (!function_exists('get_headers')) {
function
get_headers($url, $format=0) {
   
$headers = array();
   
$url = parse_url($url);
   
$host = isset($url['host']) ? $url['host'] : '';
   
$port = isset($url['port']) ? $url['port'] : 80;
   
$path = (isset($url['path']) ? $url['path'] : '/') . (isset($url['query']) ? '?' . $url['query'] : '');
   
$fp = fsockopen($host, $port, $errno, $errstr, 3);
    if (
$fp)
    {
       
$hdr = "GET $path HTTP/1.1\r\n";
       
$hdr .= "Host: $host \r\n";
       
$hdr .= "Connection: Close\r\n\r\n";
       
fwrite($fp, $hdr);
        while (!
feof($fp) && $line = trim(fgets($fp, 1024)))
        {
            if (
$line == "\r\n") break;
            list(
$key, $val) = explode(': ', $line, 2);
            if (
$format)
                if (
$val) $headers[$key] = $val;
                else
$headers[] = $key;
            else
$headers[] = $line;
        }
       
fclose($fp);
        return
$headers;
    }
    return
false;
}
}
?>
php dot sirlancelot at spamgourmet dot com
7 years ago
I tried to replicate the native behavior as much as possible for systems that don't have the get_headers() function. Here it is:
<?php
if (!function_exists('get_headers')) {
function
get_headers($Url, $Format= 0, $Depth= 0) {
    if (
$Depth > 5) return;
   
$Parts = parse_url($Url);
    if (!
array_key_exists('path', $Parts))   $Parts['path'] = '/';
    if (!
array_key_exists('port', $Parts))   $Parts['port'] = 80;
    if (!
array_key_exists('scheme', $Parts)) $Parts['scheme'] = 'http';

   
$Return = array();
   
$fp = fsockopen($Parts['host'], $Parts['port'], $errno, $errstr, 30);
    if (
$fp) {
       
$Out = 'GET '.$Parts['path'].(isset($Parts['query']) ? '?'.@$Parts['query'] : '')." HTTP/1.1\r\n".
              
'Host: '.$Parts['host'].($Parts['port'] != 80 ? ':'.$Parts['port'] : '')."\r\n".
              
'Connection: Close'."\r\n";
       
fwrite($fp, $Out."\r\n");
       
$Redirect = false; $RedirectUrl = '';
        while (!
feof($fp) && $InLine = fgets($fp, 1280)) {
            if (
$InLine == "\r\n") break;
           
$InLine = rtrim($InLine);

            list(
$Key, $Value) = explode(': ', $InLine, 2);
            if (
$Key == $InLine) {
                if (
$Format == 1)
                       
$Return[$Depth] = $InLine;
                else   
$Return[] = $InLine;

                if (
strpos($InLine, 'Moved') > 0) $Redirect = true;
            } else {
                if (
$Key == 'Location') $RedirectUrl = $Value;
                if (
$Format == 1)
                       
$Return[$Key] = $Value;
                else   
$Return[] = $Key.': '.$Value;
            }
        }
       
fclose($fp);
        if (
$Redirect && !empty($RedirectUrl)) {
           
$NewParts = parse_url($RedirectUrl);
            if (!
array_key_exists('host', $NewParts))   $RedirectUrl = $Parts['host'].$RedirectUrl;
            if (!
array_key_exists('scheme', $NewParts)) $RedirectUrl = $Parts['scheme'].'://'.$RedirectUrl;
           
$RedirectHeaders = get_headers($RedirectUrl, $Format, $Depth+1);
            if (
$RedirectHeaders) $Return = array_merge_recursive($Return, $RedirectHeaders);
        }
        return
$Return;
    }
    return
false;
}}
?>
The function will handle up to five redirects.
Enjoy!
dxtrim at yahoo dot com
8 years ago
Content-Type returns a value depending only on the extension and not the real MIME TYPE.

So, bad_file.exe renamed to good_file.doc will return application/msword

A file without extension returns a 404.
Anonymous
9 years ago
I've noticed it.
Some Server will simply return the false reply header if you sent 'HEAD' request instead of 'GET'. The 'GET' request header always receiving the most actual HTTP header instead of 'HEAD' request header. But If you don't mind for a fast but risky method then 'HEAD' request is better for you.

btw ... this is get header with additional information such as User, Pass & Refferer. ...
<?php
   
function get_headers_x($url,$format=0, $user='', $pass='', $referer='') {
        if (!empty(
$user)) {
           
$authentification = base64_encode($user.':'.$pass);
           
$authline = "Authorization: Basic $authentification\r\n";
        }

        if (!empty(
$referer)) {
           
$refererline = "Referer: $referer\r\n";
        }

       
$url_info=parse_url($url);
       
$port = isset($url_info['port']) ? $url_info['port'] : 80;
       
$fp=fsockopen($url_info['host'], $port, $errno, $errstr, 30);
        if(
$fp) {
           
$head = "GET ".@$url_info['path']."?".@$url_info['query']." HTTP/1.0\r\n";
            if (!empty(
$url_info['port'])) {
               
$head .= "Host: ".@$url_info['host'].":".$url_info['port']."\r\n";
            } else {
               
$head .= "Host: ".@$url_info['host']."\r\n";
            }
           
$head .= "Connection: Close\r\n";
           
$head .= "Accept: */*\r\n";
           
$head .= $refererline;
           
$head .= $authline;
           
$head .= "\r\n";

           
fputs($fp, $head);      
            while(!
feof($fp) or ($eoheader==true)) {
                if(
$header=fgets($fp, 1024)) {
                    if (
$header == "\r\n") {
                       
$eoheader = true;
                        break;
                    } else {
                       
$header = trim($header);
                    }

                    if(
$format == 1) {
                   
$key = array_shift(explode(':',$header));
                        if(
$key == $header) {
                           
$headers[] = $header;
                        } else {
                           
$headers[$key]=substr($header,strlen($key)+2);
                        }
                    unset(
$key);
                    } else {
                       
$headers[] = $header;
                    }
                }
            }
            return
$headers;

        } else {
            return
false;
        }
    }
?>

Regards.
Donovan
stuart at sixletterwords dot com
10 years ago
hey, i came across this afew weeks ago and used the function in an app for recording info about domains that my company owns, and found that the status this returns was wrong most of the time (400 bad request or void for sites that were clearly online). then looking into it i noticed the problem was that it wasn't able to get the correct info about sites with redirections. but thats not the full problem because everything on my server was returning the wrong status too. i searched around on php.net for other info and found that fsockopen's example worked better and only needed some tweeking.

heres the function i put together from it and a small change.

<?php
if(!function_exists('get_headers')) {
   function
get_headers($url,$format=0,$httpn=0){
   
$fp = fsockopen($url, 80, $errno, $errstr, 30);
    if (
$fp) {
      
$out = "GET / HTTP/1.1\r\n";
      
$out .= "Host: $url\r\n";
      
$out .= "Connection: Close\r\n\r\n";
      
fwrite($fp, $out);
       while (!
feof($fp)) {
          
$var.=fgets($fp, 1280);
       }

   
$var=explode("<",$var);
   
$var=$var[0];
   
$var=explode("\n",$var);
   
fclose($fp);
    return
$var;
    }
    }
}
?>

this returns an array of the header (only problem being that if the site doesn't have correct html it'll pull in some content too).

hope this'll help someone else.
sey at sey dot prometheus-designs dot net
10 years ago
The replacement updated get_headers function by aeontech at gmail dot com improperly formats dates when $format = 1.

Replace:
<?
else {
$headers[strtolower($h2[0])] = trim($h2[1]);
}
?>

With:
<?
else {   
$foo = implode( ':', $h2 );
$foo = preg_replace( '/[a-zA-Z- ]*: /', '', $foo );
$headers[strtolower($h2[0])] = trim( $foo );
}
Anonymous
10 years ago
For anyone reading the previous comments, here is code that takes into account all the previous suggestions and includes a bugfix, too.

This code basically provides the "get_headers" function even on systems that are not running PHP 5.0.  It uses strtolower() on the keys, as suggested.  It uses the $h2 array instead of the $key, as suggested.  It removes a line about unsetting the $key -- no reason to unset something which is no longer used.  And I've changed the status header to be named "status" (instead of "0") in the array.  Note that if more than one header is returned without a label, they'll be stuck in "status" -- but I think status is the only header that comes back without a label, so it works for me.  So, first the code, then a sample of the usage:

<?php
if(!function_exists('get_headers')) {
  
/**
   * @return array
    * @param string $url
    * @param int $format
    * @desc Fetches all the headers
    * @author cpurruc fh-landshut de
    * @modified by dotpointer
    * @modified by aeontech
    */
   
function get_headers($url,$format=0) {
       
$url_info=parse_url($url);
       
$port = isset($url_info['port']) ? $url_info['port'] : 80;
       
$fp=fsockopen($url_info['host'], $port, $errno, $errstr, 30);
        if(
$fp) {
           
$head = "HEAD ".@$url_info['path']."?".@$url_info['query'];
           
$head .= " HTTP/1.0\r\nHost: ".@$url_info['host']."\r\n\r\n";
           
fputs($fp, $head);
            while(!
feof($fp)) {
                if(
$header=trim(fgets($fp, 1024))) {
                    if(
$format == 1) {
                       
$h2 = explode(':',$header);
                       
// the first element is the http header type, such as HTTP/1.1 200 OK,
                        // it doesn't have a separate name, so we have to check for it.
                       
if($h2[0] == $header) {
                           
$headers['status'] = $header;
                        }
                        else {
                           
$headers[strtolower($h2[0])] = trim($h2[1]);
                        }
                    }
                    else {
                       
$headers[] = $header;
                    }
                }
            }
            return
$headers;
        }
        else {
            return
false;
        }
    }
}
?>

OK?  Here's the usage:

<?php
$response
= get_headers('http://www.example.com/', 1);
if (!
$response) {
    echo
'Unable to initiate connection.';
}
else {
   
print_r($response);
}
?>
aeontech at gmail dot com
11 years ago
In response to dotpointer's modification of Jamaz' solution...

Here is a small modification of your function, this adds the emulation of the optional $format parameter.

<?php
if(!function_exists('get_headers')) {
   
   
/**
    * @return array
    * @param string $url
    * @param int $format
    * @desc Fetches all the headers
    * @author cpurruc fh-landshut de
    * @modified by dotpointer
    * @modified by aeontech
    */
   
function get_headers($url,$format=0)
    {
       
$url_info=parse_url($url);
       
$port = isset($url_info['port']) ? $url_info['port'] : 80;
       
$fp=fsockopen($url_info['host'], $port, $errno, $errstr, 30);
       
        if(
$fp)
        {
           
$head = "HEAD ".@$url_info['path']."?".@$url_info['query']." HTTP/1.0\r\nHost: ".@$url_info['host']."\r\n\r\n";      
           
fputs($fp, $head);      
            while(!
feof($fp))
            {
                if(
$header=trim(fgets($fp, 1024)))
                {
                    if(
$format == 1)
                    {
                       
$key = array_shift(explode(':',$header));
                       
// the first element is the http header type, such as HTTP 200 OK,
                        // it doesn't have a separate name, so we have to check for it.
                       
if($key == $header)
                        {
                           
$headers[] = $header;
                        }
                        else
                        {
                           
$headers[$key]=substr($header,strlen($key)+2);
                        }
                        unset(
$key);
                    }
                    else
                    {
                       
$headers[] = $header;
                    }
                }
            }
            return
$headers;
        }
        else
        {
            return
false;
        }
    }
}
?>
Lukas Najduk
5 years ago
Unfortunately there is still no useful output format to handle redirects.

This function will bring all non-broken headers into a usable format. Too bad it has to call the get_headers() funtion 2 times, but i dont see any other possibility right now.

<?php
function page_get_headers($crawl_uri) {
   
// get the array values where to split the second get headers return
   
$headers = get_headers($crawl_uri, 1);
    if (empty(
$headers)) {
        return array();
    }
   
$splitmarks = array();
    foreach (
$headers as $key=>$h) {
        if (
is_numeric($key)) {
           
array_push($splitmarks, $h);
        }
    }

   
// get the "real" headers
   
$headers_final = array();
   
$i = 0;
   
$headers = get_headers($crawl_uri);
    foreach (
$headers as $head) {
       
// if the value is one of the splitmarks, start the next header
       
if (array_key_exists($i, $splitmarks) && $head === $splitmarks[$i]) {
           
$i++;
        }  
        else {
           
// get the headers name
           
$tmp = explode(": ", $head, 2);
           
// check if the header is already existing, if yes, parse the similar header to an array
           
if (!empty($headers_final[$i-1][$tmp[0]])) {
                if (
is_array($headers_final[$i-1][$tmp[0]])) {
                   
array_push($headers_final[$i-1][$tmp[0]], $tmp[1]);
                }
                else {
                   
$headers_final[$i-1][$tmp[0]] = array($headers_final[$i-1][$tmp[0]], $tmp[1]);
                }
            }
            else {
               
$headers_final[$i-1][$tmp[0]] = $tmp[1];  
            }  
        }
    }
    return
$headers_final;
}
?>
Backslider
4 years ago
It should be noted that rather than returning "false" on failure, this function (and others) return a big phat WARNING that will halt your script in its tracks if you do not have error reporting /warning turned off.

Thats just insane!  Any function that does something like fetch a URL should simply return false, without a warning, if the URL fails for whatever reason other than it is badly formatted.
drfickle2 at yahoo dot com
10 years ago
aeontech, this the below change adds support for SSL connections. Thanks for the code!

        if (isset($url_info['scheme']) && $url_info['scheme'] == 'https') {
            $port = 443;
            $fp=fsockopen('ssl://'.$url_info['host'], $port, $errno, $errstr, 30);
        } else {
           $port = isset($url_info['port']) ? $url_info['port'] : 80;
            $fp=fsockopen($url_info['host'], $port, $errno, $errstr, 30);
        }
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