get_headers

(PHP 5, PHP 7)

get_headers — 取得服务器响应一个 HTTP 请求所发送的所有标头

说明

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

get_headers() 返回一个数组，包含有服务器响应一个 HTTP 请求所发送的标头。

参数

url

目标 URL。

format

如果将可选的 format 参数设为 1，则 get_headers() 会解析相应的信息并设定数组的键名。

返回值

返回包含有服务器响应一个 HTTP 请求所发送标头的索引或关联数组，如果失败则返回 FALSE。

更新日志

版本 说明
5.1.3 自 PHP 5.1.3 起本函数使用默认的流上下文，其可以用 stream_context_get_default() 函数设定和修改。

范例

Example #1 get_headers() 例子

<?php
$url = 'http://www.example.com';

print_r(get_headers($url));

print_r(get_headers($url, 1));
?>

以上例程的输出类似于：

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');
?>

参见

User Contributed Notes

dongchao769390531 at 163 dot com 07-Jun-2017 03:43
<?php
/**
 * We can use get_headers to check image url is real image resource or not
 * Only check image url format is not safe
 * @param string $link
 * @return boolean
 */
function checkImageContentType($link){
    //Set the second parameter as 1, then get "Content-Type" value
    $imgHeader = get_headers($link,1);
    if(!isset($imgHeader['Content-Type'])){
        //No "Content-Type" in headers, then that image url is not a real image resource
        return false;
    }
    //A regular pattern to check "Content-Type" value
    $imgPattern = '/^image\/(jpeg|gif|png|svg)[;\w\=\+]*$/';
    //Some image resource's "Content-Type" may be an array
    if(is_array($imgHeader['Content-Type'])){
        //Check the resource's Content-Type is accord with the regular pattern or not
        $typeArr = preg_grep($imgPattern,$imgHeader['Content-Type']);
        if(empty($typeArr)){
            return false;
        }
    }elseif(is_string($imgHeader['Content-Type'])){
        //Image resource's "Content-Type" may be a simple string
        if(!preg_match($imgPattern,$imgHeader['Content-Type'])){
            return false;
        }
    }else{
        return false;
    }
    return true;
}

//A image url(php logo from php.net), a legal image resource url
$link = 'http://php.net/images/logos/php-logo.svg';
var_dump(checkImageContentType($link));// return true

//An illegal image resource url
$link = 'http://php.net/images/logos.jpg';
var_dump(checkImageContentType($link));// return false
?>
bunny at bunny dot hu 22-Oct-2016 11:26
If the URL redirected and the new target is also redirected, we got the Locations in array. Also we got the HTTP codes in a number indexed values.

Here a PART of the header (not all), how it is look like with this redirection chain ( the id=4 is the landing page):
/test.php?id=1 -> /test.php?id=2 -> /test.php?id=3 -> /test.php?id=4

array
(
    [0] => HTTP/1.1 302 Moved Temporarily

    [Location] => Array
        (
            [0] => /test.php?id=2
            [1] => /test.php?id=3
            [2] => /test.php?id=4
        )

    [1] => HTTP/1.1 302 Moved Temporarily
    [2] => HTTP/1.1 302 Moved Temporarily
    [3] => HTTP/1.1 200 OK
)

In a typical situation we need only the landing page information, so here is a small code to get it:

$result = array();
$header = get_headers($url, 1);
foreach ($header as $key=>$value) {
    if (is_array($value)) {
        $value = end($value);
    }
    $result[$key] = $value;
}
sidnash56 at gmail dot com 22-Jun-2016 08:30
To check URL validity, this has been working nicely for me:

function url_valid(&$url) {
  $file_headers = @get_headers($url);
  if ($file_headers === false) return false; // when server not found
  foreach($file_headers as $header) { // parse all headers:
    // corrects $url when 301/302 redirect(s) lead(s) to 200:
    if(preg_match("/^Location: (http.+)$/",$header,$m)) $url=$m[1];
    // grabs the last $header $code, in case of redirect(s):
    if(preg_match("/^HTTP.+\s(\d\d\d)\s/",$header,$m)) $code=$m[1];
  } // End foreach...
  if($code==200) return true; // $code 200 == all OK
  else return false; // All else has failed, so this must be a bad link
} // End function url_exists
bobray at softville dot com 11-May-2015 02:29
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.
pegasus at vaultwiki dot org 29-Apr-2015 11:41
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.
cees at cornelisdigitaal dot nl 23-Feb-2015 06:20
@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 24-Nov-2013 06:55
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);
?>
Jim Greene 09-Jul-2013 11:47
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.
Backslider 16-Feb-2012 04:06
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.
damolp at hotmail dot com 04-Jul-2011 02:43
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.
Lukas Najduk 11-Jan-2011 12:36
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;
}
?>
Weboide 26-Sep-2010 03:13
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=gb2312"
  [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=gb2312"
    [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"
  }
.....
}*/
?>
nick at innovaweb dot co dot uk 03-May-2010 02:28
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
php at hm2k dot org 28-Jan-2010 07:20
<?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;
}
?>
gabe at vtunnel dot com 22-Apr-2009 10:23
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;
    }
}
?>
info at marc-gutt dot de 21-Jun-2008 02:04
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 $headers;
    }
    return false;
}
}
?>
php dot sirlancelot at spamgourmet dot com 05-Jun-2008 10:59
I tried to replicate the native behavior as much as possible for systems that don't have the get_headers() function. Here it is:
<?php
if (!function_exists('get_headers')) {
function get_headers($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 17-Jan-2008 10:16
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.
13-Nov-2006 09:29
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
10-May-2006 01:10
If you want to get headers that current PHP process is going to send back to browser, see headers_list()
stuart at sixletterwords dot com 14-Sep-2005 09:52
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 28-Jul-2005 01:10
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 );
}
drfickle2 at yahoo dot com 27-Jul-2005 02:01
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);
        }
15-Jul-2005 10:37
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 24-Dec-2004 02:20
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;
        }
    }
}
?>