Apache模块 mod_include · Apache 2.2 中文官方文档

# Apache模块 mod_include | [说明](#calibre_link-11) | 实现服务端包含文档(SSI)处理 | | --- | --- | | [状态](#calibre_link-12) | 基本(B) | | [模块名](#calibre_link-13) | include_module | | [源文件](#calibre_link-14) | mod_include.c | | [兼容性](#calibre_link-58) | Implemented as an output filter since Apache 2.0 | ### 概述 This module provides a filter which will process files before they are sent to the client. The processing is controlled by specially formatted SGML comments, referred to as <dfn class="calibre27">elements</dfn>. These elements allow conditional text, the inclusion of other files or programs, as well as the setting and printing of environment variables. ## Enabling Server-Side Includes Server Side Includes are implemented by the `INCLUDES` [filter](#calibre_link-15). If documents containing server-side include directives are given the extension .shtml, the following directives will make Apache parse them and assign the resulting document the mime type of `text/html`: ``` AddType text/html .shtml AddOutputFilter INCLUDES .shtml ``` The following directive must be given for the directories containing the shtml files (typically in a `<Directory>` section, but this directive is also valid in `.htaccess` files if `AllowOverride` `Options` is set): ``` Options +Includes ``` For backwards compatibility, the `server-parsed` [处理器](#calibre_link-253) also activates the INCLUDES filter. As well, Apache will activate the INCLUDES filter for any document with mime type `text/x-server-parsed-html`或`text/x-server-parsed-html3` (and the resulting output will have the mime type `text/html`). For more information, see our [Tutorial on Server Side Includes](#calibre_link-267). ## PATH_INFO with Server Side Includes Files processed for server-side includes no longer accept requests with `PATH_INFO` (trailing pathname information) by default. You can use the `AcceptPathInfo` directive to configure the server to accept requests with `PATH_INFO`. ## Basic Elements The document is parsed as an HTML document, with special commands embedded as SGML comments. A command has the syntax: ```  ``` The value will often be enclosed in double quotes, but single quotes (`'`) and backticks (`` ` ``) are also possible. Many commands only allow a single attribute-value pair. Note that the comment terminator (`-->`) should be preceded by whitespace to ensure that it isn't considered part of an SSI token. Note that the leading ` ``` If the script returns a `Location:` header instead of output, then this will be translated into an HTML anchor. `include virtual` element should be used in preference to `exec cgi`. In particular, if you need to pass additional arguments to a CGI program, using the query string, this cannot be done with `exec cgi`, but can be done with `include virtual`, as shown here: ```  ``` `cmd` The server will execute the given string using `/bin/sh`. The [include variables](#calibre_link-568) are available to the command, in addition to the usual set of CGI variables. The use of `#include virtual` is almost always prefered to using either `#exec cgi`或`#exec cmd`. The former (`#include virtual`) uses the standard Apache sub-request mechanism to include files or scripts. It is much better tested and maintained. In addition, on some platforms, like Win32, and on unix when using [suexec](#calibre_link-230), you cannot pass arguments to a command in an `exec` directive, or otherwise include spaces in the command. Thus, while the following will work under a non-suexec configuration on unix, it will not produce the desired result under Win32, or when running suexec: ```  ``` ### The fsize Element This command prints the size of the specified file, subject to the `sizefmt` format specification. Attributes: `file` The value is a path relative to the directory containing the current document being parsed. `virtual` The value is a (%-encoded) URL-path. If it does not begin with a slash (/) then it is taken to be relative to the current document. Note, that this does _not_ print the size of any CGI output, but the size of the CGI script itself. ### The flastmod Element This command prints the last modification date of the specified file, subject to the `timefmt` format specification. The attributes are the same as for the `fsize` command. ### The include Element This command inserts the text of another document or file into the parsed file. Any included file is subject to the usual access control. If the directory containing the parsed file has [Options](#calibre_link-153) `IncludesNOEXEC` set, then only documents with a text [MIME-type](#calibre_link-223 "see glossary") (`text/plain`, `text/html` etc.) will be included. Otherwise CGI scripts are invoked as normal using the complete URL given in the command, including any query string. An attribute defines the location of the document; the inclusion is done for each attribute given to the include command. The valid attributes are: `file` The value is a path relative to the directory containing the current document being parsed. It cannot contain `../`, nor can it be an absolute path. Therefore, you cannot include files that are outside of the document root, or above the current document in the directory structure. The `virtual` attribute should always be used in preference to this one. `<a id="calibre_link-569" name="includevirtual" class="pcalibre1 pcalibre">virtual</a>` The value is a (%-encoded) URL-path. The URL cannot contain a scheme or hostname, only a path and an optional query string. If it does not begin with a slash (/) then it is taken to be relative to the current document. A URL is constructed from the attribute, and the output the server would return if the URL were accessed by the client is included in the parsed output. Thus included files can be nested. If the specified URL is a CGI program, the program will be executed and its output inserted in place of the directive in the parsed file. You may include a query string in a CGI url: ```  ``` `include virtual` should be used in preference to `exec cgi` to include the output of CGI programs into an HTML document. ### The printenv Element This prints out a listing of all existing variables and their values. Special characters are entity encoded (see the `echo` element for details) before being output. There are no attributes. ### 示例 ```  ``` ### The set Element This sets the value of a variable. Attributes: `var` The name of the variable to set. `value` The value to give a variable. ### 示例 ```  ``` ## Include Variables In addition to the variables in the standard CGI environment, these are available for the `echo` command, for `if`和`elif`, and to any program invoked by the document. `DATE_GMT` The current date in Greenwich Mean Time. `DATE_LOCAL` The current date in the local time zone. `DOCUMENT_NAME` The filename (excluding directories) of the document requested by the user. `DOCUMENT_URI` The (%-decoded) URL path of the document requested by the user. Note that in the case of nested include files, this is _not_ the URL for the current document. `LAST_MODIFIED` The last modification date of the document requested by the user. `QUERY_STRING_UNESCAPED` If a query string is present, this variable contains the (%-decoded) query string, which is _escaped_ for shell usage (special characters like `&` etc. are preceded by backslashes). ## Variable Substitution Variable substitution is done within quoted strings in most cases where they may reasonably occur as an argument to an SSI directive. This includes the `config`, `exec`, `flastmod`, `fsize`, `include`, `echo`, and `set` directives, as well as the arguments to conditional operators. You can insert a literal dollar sign into the string using backslash quoting: ```  ``` If a variable reference needs to be substituted in the middle of a character sequence that might otherwise be considered a valid identifier in its own right, it can be disambiguated by enclosing the reference in braces, _a la_ shell substitution: ```  ``` This will result in the `Zed` variable being set to "`X_Y`" if `REMOTE_HOST` is "`X`" and `REQUEST_METHOD` is "`Y`". The below example will print "in foo" if the `DOCUMENT_URI` is `/foo/file.html`, "in bar" if it is `/bar/file.html` and "in neither" otherwise: ```  in foo  in bar  in neither  ``` ## Flow Control Elements The basic flow control elements are: ```     ``` `if` element works like an if statement in a programming language. The test condition is evaluated and if the result is true, then the text until the next `elif`, `else`或`endif` element is included in the output stream. `elif`或`else` statements are be used to put text into the output stream if the original test_condition was false. These elements are optional. `endif` element ends the `if` element and is required. test_condition is one of the following: `string` true if string is not empty `string1 = string2 string1 == string2 string1 != string2` Compare string1 with string2. If string2 has the form `/string2/` then it is treated as a regular expression. Regular expressions are implemented by the [PCRE](http://www.pcre.org) engine and have the same syntax as those in [perl 5](http://www.perl.com). Note that `==` is just an alias for `=` and behaves exactly the same way. If you are matching positive (`=`或`==`), you can capture grouped parts of the regular expression. The captured parts are stored in the special variables `$1` .. `$9`. ### 示例 ```    ``` `string1 < string2 string1 <= string2 string1 > string2 string1 >= string2` Compare string1 with string2. Note, that strings are compared _literally_ (using `strcmp(3)`). Therefore the string "100" is less than "20". `( test_condition )` true if test_condition is true `! test_condition` true if test_condition is false `test_condition1 && test_condition2` true if both test_condition1和test_condition2 are true `test_condition1 || test_condition2` true if either test_condition1或test_condition2 is true "`=`" and "`!=`" bind more tightly than "`&&`" and "`||`". "`!`" binds most tightly. Thus, the following are equivalent: ```   ``` The boolean operators `&&`和`||` share the same priority. So if you want to bind such an operator more tightly, you should use parentheses. Anything that's not recognized as a variable or an operator is treated as a string. Strings can also be quoted: `'string'`. Unquoted strings can't contain whitespace (blanks and tabs) because it is used to separate tokens such as variables. If multiple strings are found in a row, they are concatenated using blanks. So, ``` <var class="calibre40">string1</var> <var class="calibre40">string2</var> results in <var class="calibre40">string1</var> <var class="calibre40">string2</var> 和 '<var class="calibre40">string1</var> <var class="calibre40">string2</var>' results in <var class="calibre40">string1</var> <var class="calibre40">string2</var>. ``` ### Optimization of Boolean Expressions If the expressions become more complex and slow down processing significantly, you can try to optimize them according to the evaluation rules: * Expressions are evaluated from left to right * Binary boolean operators (`&&`和`||`) are short circuited wherever possible. In conclusion with the rule above that means, `mod_include` evaluates at first the left expression. If the left result is sufficient to determine the end result, processing stops here. Otherwise it evaluates the right side and computes the end result from both left and right results. * Short circuit evaluation is turned off as long as there are regular expressions to deal with. These must be evaluated to fill in the backreference variables (`$1` .. `$9`). If you want to look how a particular expression is handled, you can recompile `mod_include` using the `-DDEBUG_INCLUDE` compiler option. This inserts for every parsed expression tokenizer information, the parse tree and how it is evaluated into the output sent to the client. ## SSIEndTag 指令 | [说明](#calibre_link-18) | String that ends an include element | | --- | --- | | [语法](#calibre_link-19) | `SSIEndTag tag` | | [默认值](#calibre_link-24) | `SSIEndTag "-->"` | | [作用域](#calibre_link-20) | server config, virtual host | | [状态](#calibre_link-21) | 基本(B) | | [模块](#calibre_link-22) | mod_include | | [兼容性](#calibre_link-137) | 仅在 Apache 2.0.30 及以后的版本中可用 | This directive changes the string that `mod_include` looks for to mark the end of an include element. ### 示例 ``` SSIEndTag "%>" ``` ### 参见 * `SSIStartTag` ## SSIErrorMsg 指令 | [说明](#calibre_link-18) | Error message displayed when there is an SSI error | | --- | --- | | [语法](#calibre_link-19) | `SSIErrorMsg message` | | [默认值](#calibre_link-24) | `SSIErrorMsg "[an error occurred while processing this directive]"` | | [作用域](#calibre_link-20) | server config, virtual host, directory, .htaccess | | [覆盖项](#calibre_link-66) | All | | [状态](#calibre_link-21) | 基本(B) | | [模块](#calibre_link-22) | mod_include | | [兼容性](#calibre_link-137) | 仅在 Apache 2.0.30 及以后的版本中可用 | `SSIErrorMsg` directive changes the error message displayed when `mod_include` encounters an error. For production servers you may consider changing the default error message to `""` so that the message is not presented to the user. This directive has the same effect as the `` element. ### 示例 ``` SSIErrorMsg "" ``` ## SSIStartTag 指令 | [说明](#calibre_link-18) | String that starts an include element | | --- | --- | | [语法](#calibre_link-19) | `SSIStartTag tag` | | [默认值](#calibre_link-24) | `SSIStartTag "` element. ### 示例 ``` SSITimeFormat "%R, %B %d, %Y" ``` The above directive would cause times to be displayed in the format "22:26, June 14, 2002". ## SSIUndefinedEcho 指令 | [说明](#calibre_link-18) | String displayed when an unset variable is echoed | | --- | --- | | [语法](#calibre_link-19) | `SSIUndefinedEcho string` | | [默认值](#calibre_link-24) | `SSIUndefinedEcho "(none)"` | | [作用域](#calibre_link-20) | server config, virtual host, directory, .htaccess | | [覆盖项](#calibre_link-66) | All | | [状态](#calibre_link-21) | 基本(B) | | [模块](#calibre_link-22) | mod_include | | [兼容性](#calibre_link-137) | 仅在 Apache 2.0.34 及以后的版本中可用 | This directive changes the string that `mod_include` displays when a variable is not set and "echoed". ### 示例 ``` SSIUndefinedEcho "" ``` ## XBitHack 指令 | [说明](#calibre_link-18) | Parse SSI directives in files with the execute bit set | | --- | --- | | [语法](#calibre_link-19) | `XBitHack on|off|full` | | [默认值](#calibre_link-24) | `XBitHack off` | | [作用域](#calibre_link-20) | server config, virtual host, directory, .htaccess | | [覆盖项](#calibre_link-66) | Options | | [状态](#calibre_link-21) | 基本(B) | | [模块](#calibre_link-22) | mod_include | `XBitHack` directive controls the parsing of ordinary html documents. This directive only affects files associated with the [MIME-type](#calibre_link-223 "see glossary") `text/html`. `XBitHack` can take on the following values: `off` No special treatment of executable files. `on` Any `text/html` file that has the user-execute bit set will be treated as a server-parsed html document. `full` As for `on` but also test the group-execute bit. If it is set, then set the `Last-modified` date of the returned file to be the last modified time of the file. If it is not set, then no last-modified date is sent. Setting this bit allows clients and proxies to cache the result of the request. ### 注意 You would not want to use the full option, unless you assure the group-execute bit is unset for every SSI script which might `#include` a CGI or otherwise produces different output on each hit (or could potentially change on subsequent requests).