$_SERVER
  $HTTP_SERVER_VARS [removed]
  (PHP 4 >= 4.1.0, PHP 5)
$_SERVER -- $HTTP_SERVER_VARS [removed] — Server and execution environment information
  
 
 
  Description
  
   $_SERVER is an array containing information
   such as headers, paths, and script locations. The entries in this
   array are created by the web server. There is no guarantee that
   every web server will provide any of these; servers may omit some,
   or provide others not listed here. That said, a large number of
   these variables are accounted for in the » CGI/1.1 specification, so you should
   be able to expect those.
  
  Note: 
   
     Prior to PHP 5.4.0, $HTTP_SERVER_VARS contained the same initial
     information, but was not a superglobal.
     (Note that $HTTP_SERVER_VARS and $_SERVER
     were different variables and that PHP handled them as such.)
   
  
  
 
  Indices
  
   You may or may not find any of the following elements in
   $_SERVER. Note that few, if any, of these will be
   available (or indeed have any meaning) if running PHP on the
   command line.
  
  
   
    
     - 
'PHP_SELF'
- 
      
       The filename of the currently executing script, relative to
       the document root. For instance,
       $_SERVER['PHP_SELF'] in a script at the
       address http://example.com/foo/bar.php
       would be /foo/bar.php.
       The __FILE__
       constant contains the full path and filename of the current (i.e.
       included) file.
      
      
       If PHP is running as a command-line processor this variable contains
       the script name since PHP 4.3.0. Previously it was not available.
      
     
- 
'argv'
- 
      
       Array of arguments passed to the script. When the script is
       run on the command line, this gives C-style access to the
       command line parameters. When called via the GET method, this
       will contain the query string.
      
     
- 
'argc'
- 
      
       Contains the number of command line parameters passed to the
       script (if run on the command line).
      
     
- 
'GATEWAY_INTERFACE'
- 
      
       What revision of the CGI specification the server is using;
       i.e. 'CGI/1.1'.
      
     
- 
'SERVER_ADDR'
- 
      
       The IP address of the server under which the current script is
       executing.
      
     
- 
'SERVER_NAME'
- 
      
       The name of the server host under which the current script is
       executing. If the script is running on a virtual host, this
       will be the value defined for that virtual host.
      
     
- 
'SERVER_SOFTWARE'
- 
      
       Server identification string, given in the headers when
       responding to requests.
      
     
- 
'SERVER_PROTOCOL'
- 
      
       Name and revision of the information protocol via which the
       page was requested; i.e. 'HTTP/1.0';
      
     
- 
'REQUEST_METHOD'
- 
      
       Which request method was used to access the page; i.e. 'GET',
       'HEAD', 'POST', 'PUT'.
      
      Note: 
        
        PHP script is terminated after sending headers (it means after
        producing any output without output buffering) if the request method
        was HEAD.
        
 
- 
'REQUEST_TIME'
- 
      
       The timestamp of the start of the request. Available since PHP 5.1.0.
      
     
- 
'REQUEST_TIME_FLOAT'
- 
      
       The timestamp of the start of the request, with microsecond precision.
       Available since PHP 5.4.0.
      
     
- 
'QUERY_STRING'
- 
      
       The query string, if any, via which the page was accessed.
      
     
- 
'DOCUMENT_ROOT'
- 
      
       The document root directory under which the current script is
       executing, as defined in the server's configuration file.
      
     
- 
'HTTP_ACCEPT'
- 
      
       Contents of the Accept: header from the
       current request, if there is one.
      
     
- 
'HTTP_ACCEPT_CHARSET'
- 
      
       Contents of the Accept-Charset: header
       from the current request, if there is one. Example:
       'iso-8859-1,*,utf-8'.
      
     
- 
'HTTP_ACCEPT_ENCODING'
- 
      
       Contents of the Accept-Encoding: header
       from the current request, if there is one. Example: 'gzip'.
      
     
- 
'HTTP_ACCEPT_LANGUAGE'
- 
      
       Contents of the Accept-Language: header
       from the current request, if there is one. Example: 'en'.
      
     
- 
'HTTP_CONNECTION'
- 
      
       Contents of the Connection: header from
       the current request, if there is one. Example: 'Keep-Alive'.
      
     
- 
'HTTP_HOST'
- 
      
       Contents of the Host: header from the
       current request, if there is one.
      
     
- 
'HTTP_REFERER'
- 
      
       The address of the page (if any) which referred the user
       agent to the current page. This is set by the user agent. Not
       all user agents will set this, and some provide the ability
       to modify HTTP_REFERER as a feature. In
       short, it cannot really be trusted.
      
     
- 
'HTTP_USER_AGENT'
- 
      
       Contents of the User-Agent: header from
       the current request, if there is one. This is a string
       denoting the user agent being which is accessing the page. A
       typical example is: Mozilla/4.5 [en] (X11; U;
       Linux 2.2.9 i586). Among other things, you
       can use this value with get_browser() to
       tailor your page's output to the capabilities of the user
       agent.
      
     
- 
'HTTPS'
- 
      
       Set to a non-empty value if the script was queried through the HTTPS
       protocol.
      
      Note: 
       
        Note that when using ISAPI with IIS, the value will be 
        off if the request was not made through the HTTPS
        protocol.
       
       
 
- 
'REMOTE_ADDR'
- 
      
       The IP address from which the user is viewing the current
       page.
      
     
- 
'REMOTE_HOST'
- 
      
       The Host name from which the user is viewing the current
       page.  The reverse dns lookup is based off the 
       REMOTE_ADDR of the user.
      
      Note: 
       
        Your web server must be configured to create this variable. For
        example in Apache you'll need HostnameLookups On
        inside httpd.conf for it to exist.  See also
        gethostbyaddr().
       
       
 
- 
'REMOTE_PORT'
- 
      
       The port being used on the user's machine to communicate with
       the web server.
      
     
- 
'REMOTE_USER'
- 
      
        The authenticated user.
      
     
- 
'REDIRECT_REMOTE_USER'
- 
      
        The authenticated user if the request is internally redirected.
      
     
- 
'SCRIPT_FILENAME'
- 
      
       The absolute pathname of the currently executing script.
        Note: 
         
         If a script is executed with the CLI, as a relative path,
         such as file.php or 
         ../file.php, 
         $_SERVER['SCRIPT_FILENAME'] will 
         contain the relative path specified by the user.
         
 
- 
'SERVER_ADMIN'
- 
      
       The value given to the SERVER_ADMIN (for Apache) directive in
       the web server configuration file. If the script is running
       on a virtual host, this will be the value defined for that
       virtual host.
      
     
- 
'SERVER_PORT'
- 
      
       The port on the server machine being used by the web server
       for communication. For default setups, this will be '80';
       using SSL, for instance, will change this to whatever your
       defined secure HTTP port is.
      
      Note: 
       
        Under the Apache 2, you must set UseCanonicalName = On, 
        as well as UseCanonicalPhysicalPort = On in order to
        get the physical (real) port, otherwise, this value can be spoofed and it
        may or may not return the physical port value.
        It is not safe to rely on this value in security-dependent contexts.
       
       
 
- 
'SERVER_SIGNATURE'
- 
      
       String containing the server version and virtual host name
       which are added to server-generated pages, if enabled.
      
     
- 
'PATH_TRANSLATED'
- 
      
       Filesystem- (not document root-) based path to the current
       script, after the server has done any virtual-to-real
       mapping.
      
      Note: 
       
        As of PHP 4.3.2, PATH_TRANSLATED is no longer set 
        implicitly under the Apache 2 SAPI in contrast 
        to the situation in Apache 1, where it's set to the same value as 
        the SCRIPT_FILENAME server variable when it's not 
        populated by Apache.  This change was made to comply with the 
        CGI specification that 
        PATH_TRANSLATED should only exist if 
        PATH_INFO is defined.
       
       
        Apache 2 users may use AcceptPathInfo = On inside
        httpd.conf to define PATH_INFO.
       
       
 
- 
'SCRIPT_NAME'
- 
      
       Contains the current script's path. This is useful for pages
       which need to point to themselves.
       The __FILE__
       constant contains the full path and filename of the current (i.e.
       included) file.
      
     
- 
'REQUEST_URI'
- 
      
       The URI which was given in order to access this page; for
       instance, '/index.html'.
      
     
- 
'PHP_AUTH_DIGEST'
- 
      
       When doing Digest HTTP authentication this variable is set 
       to the 'Authorization' header sent by the client (which you 
       should then use to make the appropriate validation).
      
     
- 
'PHP_AUTH_USER'
- 
      
       When doing HTTP authentication this variable is set to the 
       username provided by the user.
      
     
- 
'PHP_AUTH_PW'
- 
      
       When doing HTTP authentication this variable is set to the 
       password provided by the user.
      
     
- 
'AUTH_TYPE'
- 
      
       When doing HTTP authentication this variable is set to the 
       authentication type.
      
     
- 
'PATH_INFO'
- 
      
       Contains any client-provided pathname information trailing the
       actual script filename but preceding the query string, if
       available. For instance, if the current script was accessed via
       the
       URL http://www.example.com/php/path_info.php/some/stuff?foo=bar,
       then $_SERVER['PATH_INFO'] would
       contain /some/stuff.
      
     
- 
'ORIG_PATH_INFO'
- 
      
       Original version of 'PATH_INFO' before processed by
       PHP.
      
     
 
 
 
 
 
  Examples
  
   
    Example #1 $_SERVER example
    
<?php
echo $_SERVER['SERVER_NAME'];
?>
     
    The above example will output
something similar to:
 
  
  
 
 
  Notes
  Note: 
This is a 'superglobal', or
automatic global, variable. This simply means that it is available in
all scopes throughout a script. There is no need to do
global $variable; to access it within functions or methods.