192

Chapter 14. Apache HTTP Server

14.5.15.

LoadModule

LoadModule

is used to load in Dynamic Shared Object (DSO) modules. More information on the the

Apache HTTP Server's DSO support, including exactly how to use the

LoadModule

directive, can be

found in Section 14.7. Note, the load order of the modules is no longer important with Apache HTTP

Server 2.0. See Section 14.2.1.3 for more information about Apache HTTP Server 2.0 DSO support.

14.5.16.

IfDefine

The

IfDefine

and

/IfDefine

tags surround configuration directives that are applied if the

"test" stated in the

IfDefine

tag is true. The directives are ignored if the test is false.

The test in the

IfDefine

tags is a parameter name (for example,

HAVE_PERL

). If the parameter

is defined, meaning that it is provided as an argument to the server's start up command, then the test

is true. In this case, when your Web server is started, the test is true and the directives contained in the

IfDefine

tags are applied.

By default,

IfDefine HAVE_SSL

tags surround the virtual host tags for your secure server.

IfDefine HAVE_SSL

tags also surround the

LoadModule

and

AddModule

directives for the

ssl_module

.

14.5.17.

ExtendedStatus

The

ExtendedStatus

directives controls whether Apache generates basic (

off

) or detailed server

status information (

on

), when the

server status

handler is called.

Server status

is called using

Location

tags. More information on calling

server status

is included in Section 14.5.65.

14.5.18.

User

The

User

directive sets the userid used by the server to answer requests.

User

's setting determines the

server's access. Any files inaccessible to this user will also be inaccessible to your website's visitors.

The default for

User

is

apache

.

The

User

should only have privileges so that it can access files which are supposed to be visible to

the outside world. The

User

is also the owner of any CGI processes spawned by the server. The

User

should not be allowed to execute any code which is not intended to be in response to HTTP requests.

Note

For security reasons, the Apache HTTP Server will refuse to run as User root. Using root as the

User will create large security holes for your Web server.

The parent

httpd

process first runs as root during normal operations but is then immediately handed

off to the apache user. The server must start as root because it needs to bind to a port below 1024

(the default port for secure Web communications is port 443; the default port for non secure Web

communications is port 80). Ports below 1024 are reserved for system use, so they can not be used by

anyone but root. Once the server has attached itself to its port, however, it hands the process off to the

User

before it accepts any connection requests.