get_headers

(PHP 5)

get_headers --  Fetches all the headers sent by the server in response to a HTTP request

Description

array get_headers ( string url [, int format] )

get_headers() returns an array with the headers sent by the server in response to a HTTP request. Returns FALSE on failure and an error of level E_WARNING will be issued.

If the optional format parameter is set to 1, get_headers() parses the response and sets the array's keys.

例子 1. get_headers() example

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

print_r(get_headers($url));

print_r(get_headers($url, 1));
?>

上例的输出类似于:

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
)


add a note add a note User Contributed Notes
eis
29-Oct-2006 10:29
denilson at vialink:

if you want just the headers, use HEAD request, not GET.
10-May-2006 07:10
If you want to get headers that current PHP process is going to send back to browser, see headers_list()
rsyring+phppost at gmail dot com
07-Apr-2006 06:08
Once again another update.  The improvements are:

HTTPS support (make sure you have SSL support enabled -- PHP5 is as simple as uncommenting extension=php_openssl.dll in php.ini)

Fixed bug with exploding the header on ':'.  This caused the location header to be broken and just return 'http'.

Set stream timeout in addition to socket timeout.

<?php

function my_get_headers($url ) {

      
$url_info=parse_url($url);
       if (isset(
$url_info['scheme']) && $url_info['scheme'] == 'https') {
          
$port = 443;
           @
$fp=fsockopen('ssl://'.$url_info['host'], $port, $errno, $errstr, 10);
       } else {
          
$port = isset($url_info['port']) ? $url_info['port'] : 80;
           @
$fp=fsockopen($url_info['host'], $port, $errno, $errstr, 10);
       }
       if(
$fp) {
          
stream_set_timeout($fp, 10);
          
$head = "HEAD ".@$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))) {
                      
$sc_pos = strpos( $header, ':' );
                       if(
$sc_pos === false ) {
                          
$headers['status'] = $header;
                       } else {
                          
$label = substr( $header, 0, $sc_pos );
                          
$value = substr( $header, $sc_pos+1 );
                          
$headers[strtolower($label)] = trim($value);
                       }
               }
           }
           return
$headers;
       }
       else {
           return
false;
       }
   }

?>
denilson at vialink dot com dot br
31-Oct-2005 05:15
This is a modified version of code from "stuart at sixletterwords dot com", at 14-Sep-2005 04:52. This version tries to emulate get_headers() function at PHP4. I think it works fairly well, and is simple. It is not the best emulation available, but it works.

Features:
- supports (and requires) full URLs.
- supports changing of default port in URL.
- stops downloading from socket as soon as end-of-headers is detected.

Limitations:
- only gets the root URL (see line with "GET / HTTP/1.1").
- don't support HTTPS (nor the default HTTPS port).

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

          
$var=preg_replace("/\r\n\r\n.*\$/",'',$var);
          
$var=explode("\r\n",$var);
           if(
$format)
           {
               foreach(
$var as $i)
               {
                   if(
preg_match('/^([a-zA-Z -]+): +(.*)$/',$i,$parts))
                      
$v[$parts[1]]=$parts[2];
               }
               return
$v;
           }
           else
               return
$var;
       }
   }
}
?>
tylerxxdurden at web dot de
25-Sep-2005 02:54
my version
cleans the input URL a little bit
(you should be able to put in almost every shit, and it should still work)
Should work for:
http://test.de
http://test.de/
www.test.de
http://test.de/
http://test.de/test.html
http://test.de/test.html?testme
...

not nice, but seems to work for me

<?
function get_headers2($url,$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) {
           if(!
$url_info['path']){
                        
$url_info['path'] = "/";
                     }
                     if(
$url_info['path'] && !$url_info['host']){
                      
$url_info['host'] = $url_info['path'];
                      
$url_info['path'] = "/";
                     }
                     if(
$url_info['host'][(strlen($url_info['host'])-1)] == "/" ){
                      
$url_info['host'][(strlen($url_info['host'])-1)] = "";
                     }
                     if(!
$url_array[scheme]){
                        
$url_array[scheme] = "http"; //we always use http links
                      
}
                    
$head = "HEAD ".@$url_info['path'];
                     if(
$url_info['query'] ){
                        
$head .= "?".@$url_info['query'];
                       }
                      
print_r($url_info);
          
$head .= " HTTP/1.0\r\nHost: ".@$url_info['host']."\r\n\r\n";
           echo
$head;
                    
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;
       }
   }
?>
stuart at sixletterwords dot com
15-Sep-2005 03:52
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.

<?
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 07:10
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 08:01
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);
       }
16-Jul-2005 04:37
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);
}
?>
Chortos-2
03-Jun-2005 05:44
aeontech, I'd edit your function a little... How about replacing this:

<?
                       $key
= array_shift(explode(':',$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);
                       }
?>

with this:

<?
                       $h2
= explode(':',$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[] = $header;
                       }
                       else
                       {
                          
$headers[ $h2[0] ] = trim($h2[1]);
                       }
?>

I think it looks a bit nicer :)
david at nothisbit dot futuresbright dot com
05-Apr-2005 07:03
After discovering that some webservers reply with "Content-Type" and others with "Content-type" I modified the function below to use strtolower($key) to make for easy checking against these case differences.
aeontech at gmail dot com
24-Dec-2004 09:20
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;
       }
   }
}
?>