[APACHE DOCUMENTATION]

Apache HTTP Server Version 1.3

You are looking at the documentation for the 1.3 version of the Apache HTTP Server, which is no longer maintained, and has been declared "end of life". If you are in fact still using the 1.3 version, please consider upgrading. The current version of the server is 2.4.

Module mod_headers

This module provides for the customization of HTTP response headers.

Status: Extension
Source File: mod_headers.c
Module Identifier: headers_module
Compatibility: Available in Apache 1.2 and later.

Summary

This module provides a directive to control the sending of HTTP headers. Headers can be merged, replaced or removed.

Directives


Header directive

Syntax: Header set|append|add header value
Syntax: Header unset header
Context: server config, virtual host, access.conf, .htaccess
Override: FileInfo
Status: Extension
Module: mod_headers

This directive can replace, merge or remove HTTP response headers during 1xx and 2xx series replies. For 3xx, 4xx and 5xx use the ErrorHeader directive.

The action it performs is determined by the first argument. This can be one of the following values:

This argument is followed by a header name, which can include the final colon, but it is not required. Case is ignored. For add, append and set a value is given as the third argument. If this value contains spaces, it should be surrounded by double quotes. For unset, no value should be given.

Order of Processing

The Header directive can occur almost anywhere within the server configuration. It is valid in the main server config and virtual host sections, inside <Directory>, <Location> and <Files> sections, and within .htaccess files.

The Header directives are processed in the following order:

  1. main server
  2. virtual host
  3. <Directory> sections and .htaccess
  4. <Location>
  5. <Files>
Order is important. These two headers have a different effect if reversed:
Header append Author "John P. Doe"
Header unset Author
This way round, the Author header is not set. If reversed, the Author header is set to "John P. Doe".

The Header directives are processed just before the response is sent by its handler. These means that some headers that are added just before the response is sent cannot be unset or overridden. This includes headers such as "Date" and "Server".

ErrorHeader directive

Syntax: ErrorHeader set|append|add header value
Syntax: ErrorHeader unset header
Context: server config, virtual host, access.conf, .htaccess
Override: FileInfo
Status: Extension
Module: mod_headers

This directive can replace, merge or remove HTTP response headers on all replies including errors, redirects, and successful responses. To add headers only on sucessful (status 2xx) responses, use the Header directive.

This directive is identical to the Header directive in all other respects. Consult this directive for more information on the syntax.


Apache HTTP Server Version 1.3

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