mod_example_hooks - Apache HTTP Server Version 2.4

Apache HTTP Server Version 2.4

Apache > HTTP Server > Documentation > Version 2.4 > Modules

# Apache Module mod_example_hooks

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Description: | Illustrates the Apache module API
Status: | Experimental
Module Identifier: | example_hooks_module
Source File: | mod_example_hooks.c

### Summary

The files in the `modules/examples` directory under the Apache distribution directory tree are provided as an example to those that wish to write modules that use the Apache API.

The main file is `mod_example_hooks.c`, which illustrates all the different callback mechanisms and call syntaxes. By no means does an add-on module need to include routines for all of the callbacks - quite the contrary!

The example module is an actual working module. If you link it into your server, enable the "example-hooks-handler" handler for a location, and then browse to that location, you will see a display of some of the tracing the example module did as the various callbacks were made.

### Topics

- Compiling the example_hooks module
- Using the `mod_example_hooks` Module

### Directives

### Bugfix checklist

- httpd changelog
- Known issues
- Report a bug

### See also

- Comments

## Compiling the example_hooks module

To include the example_hooks module in your server, follow the steps below:

1. Run `configure` with `--enable-example-hooks` option.
2. Make the server (run "`make`").

To add another module of your own:

1. `cp modules/examples/mod_example_hooks.c modules/new_module/mod_myexample.c`
2. Modify the file.
3. Create `modules/new_module/config.m4`.
   1. Add `APACHE_MODPATH_INIT(new_module)`.
   2. Copy APACHE_MODULE line with "example_hooks" from `modules/examples/config.m4`.
   3. Replace the first argument "example_hooks" with myexample.
   4. Replace the second argument with brief description of your module. It will be used in `configure --help`.
   5. If your module needs additional C compiler flags, linker flags or libraries, add them to CFLAGS, LDFLAGS and LIBS accordingly. See other `config.m4` files in modules directory for examples.
   6. Add `APACHE_MODPATH_FINISH`.
4. Create `module/new_module/Makefile.in`. If your module doesn't need special build instructions, all you need to have in that file is `include $(top_srcdir)/build/special.mk`.
5. Run ./buildconf from the top-level directory.
6. Build the server with --enable-myexample

## Using the `mod_example_hooks` Module

To activate the example_hooks module, include a block similar to the following in your `httpd.conf` file:

    <Location "/example-hooks-info">
       SetHandler example-hooks-handler
    </Location>

As an alternative, you can put the following into a `.htaccess` file and then request the file "test.example" from that location:

    AddHandler example-hooks-handler ".example"

After reloading/restarting your server, you should be able to browse to this location and see the brief display mentioned earlier.

## Example Directive

Description: | Demonstration directive to illustrate the Apache module API
Syntax: | `Example`
Context: | server config, virtual host, directory, .htaccess
Status: | Experimental
Module: | mod_example_hooks

The `Example` directive just sets a demonstration flag which the example module's content handler displays. It takes no arguments. If you browse to an URL to which the example-hooks content-handler applies, you will get a display of the routines within the module and how and in what order they were called to service the document request. The effect of this directive one can observe under the point "`Example directive declared here: YES/NO`".

Available Languages: en | fr | ko