The require() statement includes and evaluates
    the specific file.
   
     require() includes and evaluates a specific file.
     Detailed information on how this inclusion works is described in the
     documentation for include().
   
     require() and include()
     are identical in every way except how they handle failure.
     include() produces a
     Warning while
     require() results in a 
     Fatal Error.  In other words, don't hesitate to use
     require() if you want a missing file to halt processing
     of the page.  include() does not behave this way, the
     script will continue regardless.  Be sure to have an appropriate
     include_path setting as well.
   
    
Example 16-4. Basic require() examples <?php
require 'prepend.php';
require $somefile;
require ('somefile.txt');
?> |  
  | 
   
    See the include() documentation for more examples.
   
    
Note: 
      Prior to PHP 4.0.2, the following applies: require()
      will always attempt to read the target file, even if the line it's on
      never executes.  The conditional statement won't affect
      require(). However, if the line on which the
      require() occurs is not executed, neither will any of
      the code in the target file be executed.  Similarly, looping structures
      do not affect the behaviour of require(). Although
      the code contained in the target file is still subject to the loop, the
      require() itself happens only once.
     
 
   Note: Because this is a 
language construct and not a function, it cannot be called using 
variable functions
| Warning | 
Windows versions of PHP
prior to PHP 4.3.0 do not support accessing remote files via this function, even if
allow_url_fopen is enabled.
  | 
    See also include(), require_once(),
    include_once(), get_included_files(),
    eval(), file(), readfile(),
    virtual() and include_path.