# Module mod_log_referer

This module is contained in the `mod_log_referer.c` file, and is not compiled in by default. It provides for logging of the documents which reference documents on the server.

## Log file format

The log file contains a separate line for each refer. Each line has the format

> uri `->` document

where uri is the (%-escaped) URI for the document that references the one requested by the client, and document is the (%-decoded) local URL to the document being referred to.

## Directives

- RefererIgnore
- RefererLog

## RefererIgnore

Syntax: RefererIgnore string string ...
Context: server config, virtual host
Status: Extension
Module: mod_log_referer

The RefererIgnore directive adds to the list of strings to ignore in Referer headers. If any of the strings in the list is contained in the Referer header, then no referrer information will be logged for the request. Example:

> `RefererIgnore www.ncsa.uiuc.edu`

This avoids logging references from www.ncsa.uiuc.edu.

## RefererLog

Syntax: RefererLog file-pipe
Default: `RefererLog logs/referer_log`
Context: server config, virtual host
Status: Extension
Module: mod_log_referer

The RefererLog directive sets the name of the file to which the server will log the Referer header of incoming requests. File-pipe is one of

A filename
  A filename relative to the ServerRoot.
`|' followed by a command
  A program to receive the referrer log information on its standard input. Note the a new program will not be started for a VirtualHost if it inherits the RefererLog from the main server.

Security: if a program is used, then it will be run under the user who started httpd. This will be root if the server was started by root; be sure that the program is secure.

Security: See the security tips document for details on why your security could be compromised if the directory where logfiles are stored is writable by anyone other than the user that starts the server.

This directive is provided for compatibility with NCSA 1.4.