Apache HTTP Сервер Версия 2.0
Apache Module mod_headers
Описание: | Customization of HTTP request and response headers |
---|---|
Статус: | Extension |
Идентификатор модуля: | headers_module |
Исходный файл: | mod_headers.c |
Совместимость: | RequestHeader
is available only in Apache 2.0 |
Summary
This module provides directives to control and modify HTTP request and response headers. Headers can be merged, replaced or removed.
Order of Processing
The directives provided by mod_headers
can occur
almost anywhere within the server configuration. They are valid in the
main server config and virtual host sections, inside
<Directory>
,
<Location>
and
<Files>
sections,
and within .htaccess
files.
The directives are processed in the following order:
- main server
- virtual host
<Directory>
sections and.htaccess
<Files>
<Location>
Order is important. These two headers have a different effect if reversed:
RequestHeader append MirrorID "mirror 12"
RequestHeader unset MirrorID
This way round, the MirrorID
header is not set. If
reversed, the MirrorID header is set to "mirror 12".
Примеры
-
Copy all request headers that begin with "TS" to the
response headers:
Header echo ^TS
-
Add a header,
MyHeader
, to the response including a timestamp for when the request was received and how long it took to begin serving the request. This header can be used by the client to intuit load on the server or in isolating bottlenecks between the client and the server.Header add MyHeader "%D %t"
results in this header being added to the response:
MyHeader: D=3775428 t=991424704447256
-
Say hello to Joe
Header add MyHeader "Hello Joe. It took %D microseconds \
for Apache to serve this request."results in this header being added to the response:
MyHeader: Hello Joe. It took D=3775428 microseconds for Apache to serve this request.
-
Conditionally send
MyHeader
on the response if and only if header "MyRequestHeader" is present on the request. This is useful for constructing headers in response to some client stimulus. Note that this example requires the services of themod_setenvif
module.SetEnvIf MyRequestHeader value HAVE_MyRequestHeader
Header add MyHeader "%D %t mytext" env=HAVE_MyRequestHeader
If the header
MyRequestHeader: value
is present on the HTTP request, the response will contain the following header:MyHeader: D=3775428 t=991424704447256 mytext
Header Директива
Описание: | Configure HTTP response headers |
---|---|
Синтаксис: | Header [condition] set|append|add|unset|echo
header [value] [env=[!]variable] |
Контекст: | server config, virtual host, directory, .htaccess |
Перекрывает: | FileInfo |
Статус: | Extension |
Модуль: | mod_headers |
Совместимость: | Condition is available in version 2.0.51 and later |
This directive can replace, merge or remove HTTP response headers. The header is modified just after the content handler and output filters are run, allowing outgoing headers to be modified.
The optional condition can be either onsuccess
or always
. It determines, which internal header table should be
operated on. onsuccess
stands for 2xx
status codes and always
for all status codes (including
2xx
). Especially if you want to unset headers
set by certain modules, you should try out, which table is affected.
The action it performs is determined by the second argument. This can be one of the following values:
set
- The response header is set, replacing any previous header with this name. The value may be a format string.
append
- The response header is appended to any existing header of the same name. When a new value is merged onto an existing header it is separated from the existing header with a comma. This is the HTTP standard way of giving a header multiple values.
add
- The response header is added to the existing set of headers, even if this header already exists. This can result in two (or more) headers having the same name. This can lead to unforeseen consequences, and in general "append" should be used instead.
unset
- The response header of this name is removed, if it exists. If there are multiple headers of the same name, all will be removed.
echo
- Request headers with this name are echoed back in the response headers. header may be a regular expression.
This argument is followed by a header name, which
can include the final colon, but it is not required. Case is
ignored for set
, append
, add
and unset
. The header name for echo
is case sensitive and may be a regular expression.
For add
, append
and set
a
value is specified as the third argument. If value
contains spaces, it should be surrounded by doublequotes.
value may be a character string, a string containing format
specifiers or a combination of both. The following format specifiers
are supported in value:
%t |
The time the request was received in Universal Coordinated Time
since the epoch (Jan. 1, 1970) measured in microseconds. The value
is preceded by t= . |
%D |
The time from when the request was received to the time the
headers are sent on the wire. This is a measure of the duration
of the request. The value is preceded by D= . |
%{FOOBAR}e |
The contents of the environment
variable FOOBAR . |
When the Header
directive is used with the
add
, append
, or set
argument, a fourth argument may be used to specify conditions
under which the action will be taken. If the environment variable specified in the
env=...
argument exists (or if the environment
variable does not exist and env=!...
is specified)
then the action specified by the Header
directive
will take effect. Otherwise, the directive will have no effect
on the request.
The Header
directives are processed just
before the response is sent to the network. These means that it is
possible to set and/or override most headers, except for those headers
added by the header filter.
RequestHeader Директива
Описание: | Configure HTTP request headers |
---|---|
Синтаксис: | RequestHeader set|append|add|unset header
[value [env=[!]variable]] |
Контекст: | server config, virtual host, directory, .htaccess |
Перекрывает: | FileInfo |
Статус: | Extension |
Модуль: | mod_headers |
This directive can replace, merge or remove HTTP request headers. The header is modified just before the content handler is run, allowing incoming headers to be modified. The action it performs is determined by the first argument. This can be one of the following values:
set
- The request header is set, replacing any previous header with this name
append
- The request header is appended to any existing header of the same name. When a new value is merged onto an existing header it is separated from the existing header with a comma. This is the HTTP standard way of giving a header multiple values.
add
- The request header is added to the existing set of headers,
even if this header already exists. This can result in two
(or more) headers having the same name. This can lead to
unforeseen consequences, and in general
append
should be used instead. unset
- The request header of this name is removed, if it exists. If there are multiple headers of the same name, all will be removed.
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
value contains spaces, it should be surrounded by double
quotes. For unset, no value should be given.
When the RequestHeader
directive is used with the
add
, append
, or set
argument, a fourth argument may be used to specify conditions
under which the action will be taken. If the environment variable specified in the
env=...
argument exists (or if the environment
variable does not exist and env=!...
is specified)
then the action specified by the RequestHeader
directive
will take effect. Otherwise, the directive will have no effect
on the request.
The RequestHeader
directive is processed
just before the request is run by its handler in the fixup phase.
This should allow headers generated by the browser, or by Apache
input filters to be overridden or modified.