Apache HTTP Server Version 2.4

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# Apache Module mod_charset_lite

Description: | Specify character set translation or recoding
Status: | Extension
Module Identifier: | charset_lite_module
Source File: | mod_charset_lite.c

### Summary

`mod_charset_lite` allows the server to change the character set of responses before sending them to the client. In an EBCDIC environment, Apache always translates HTTP protocol content (e.g. response headers) from the code page of the Apache process locale to ISO-8859-1, but not the body of responses. In any environment, `mod_charset_lite` can be used to specify that response bodies should be translated. For example, if files are stored in EBCDIC, then `mod_charset_lite` can translate them to ISO-8859-1 before sending them to the client.

This module provides a small subset of configuration mechanisms implemented by Russian Apache and its associated `mod_charset`.

### Topics

- Common Problems

### Directives

### Bugfix checklist

- httpd changelog
- Known issues
- Report a bug

## Common Problems

### Invalid character set names

The character set name parameters of `CharsetSourceEnc` and `CharsetDefault` must be acceptable to the translation mechanism used by APR on the system where `mod_charset_lite` is deployed. These character set names are not standardized and are usually not the same as the corresponding values used in http headers. Currently, APR can only use iconv(3), so you can easily test your character set names using the iconv(1) program, as follows:

`iconv -f charsetsourceenc-value -t charsetdefault-value`

### Mismatch between character set of content and translation rules

If the translation rules don't make sense for the content, translation can fail in various ways, including:

- The translation mechanism may return a bad return code, and the connection will be aborted.
- The translation mechanism may silently place special characters (e.g., question marks) in the output buffer when it cannot translate the input buffer.

## CharsetDefault Directive

Description: | Charset to translate into
Syntax: | `CharsetDefault charset`
Context: | server config, virtual host, directory, .htaccess
Override: | FileInfo
Status: | Extension
Module: | mod_charset_lite

The `CharsetDefault` directive specifies the charset that content in the associated container should be translated to.

The value of the charset argument must be accepted as a valid character set name by the character set support in APR. Generally, this means that it must be supported by iconv.

### Example

    <Directory "/export/home/trawick/apacheinst/htdocs/convert">
        CharsetSourceEnc  UTF-16BE
        CharsetDefault    ISO-8859-1
    </Directory>

Specifying the same charset for both `CharsetSourceEnc` and `CharsetDefault` disables translation. The charset need not match the charset of the response, but it must be a valid charset on the system.

## CharsetOptions Directive

Description: | Configures charset translation behavior
Syntax: | `CharsetOptions option [option] ...`
Default: | `CharsetOptions ImplicitAdd`
Context: | server config, virtual host, directory, .htaccess
Override: | FileInfo
Status: | Extension
Module: | mod_charset_lite

The `CharsetOptions` directive configures certain behaviors of `mod_charset_lite`. Option can be one of

`ImplicitAdd | NoImplicitAdd`
  The `ImplicitAdd` keyword specifies that `mod_charset_lite` should implicitly insert its filter when the configuration specifies that the character set of content should be translated. If the filter chain is explicitly configured using the `AddOutputFilter` directive, `NoImplicitAdd` should be specified so that `mod_charset_lite` doesn't add its filter.
`TranslateAllMimeTypes | NoTranslateAllMimeTypes`
  Normally, `mod_charset_lite` will only perform translation on a small subset of possible mimetypes. When the `TranslateAllMimeTypes` keyword is specified for a given configuration section, translation is performed without regard for mimetype.

## CharsetSourceEnc Directive

Description: | Source charset of files
Syntax: | `CharsetSourceEnc charset`
Context: | server config, virtual host, directory, .htaccess
Override: | FileInfo
Status: | Extension
Module: | mod_charset_lite

The `CharsetSourceEnc` directive specifies the source charset of files in the associated container.

The value of the charset argument must be accepted as a valid character set name by the character set support in APR. Generally, this means that it must be supported by iconv.

### Example

    <Directory "/export/home/trawick/apacheinst/htdocs/convert">
        CharsetSourceEnc  UTF-16BE
        CharsetDefault    ISO-8859-1
    </Directory>

The character set names in this example work with the iconv translation support in Solaris 8.

Specifying the same charset for both `CharsetSourceEnc` and `CharsetDefault` disables translation. The charset need not match the charset of the response, but it must be a valid charset on the system.