require()
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. They both
produce a Warning, but
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 #1 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
WarningWindows versions of PHP
prior to PHP 4.3.0 do not support access of 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.
