---
name: "Apache::Constants"
section: "3pm"
platform: "linux"
package: "libapache-mod-perl"
version: "1.29.0.4-4.1+etch1"
release: "Debian 4.0 (Etch)"
platforms: ["linux"]
url: "https://new.carta.tech/Apache::Constants"
---

# Apache::Constants(3pm)

Constants defined in apache header files

## NAME

Apache::Constants - Constants defined in apache header files

## SYNOPSIS

```
    use Apache::Constants;
    use Apache::Constants ':common';
    use Apache::Constants ':response';
```

## DESCRIPTION

Server constants used by apache modules are defined in **httpd.h** and other header files, this module gives Perl access to those constants.

## EXPORT TAGS

- common

  This tag imports the most commonly used constants.

  ```
   OK
   DECLINED
   DONE
   NOT_FOUND
   FORBIDDEN
   AUTH_REQUIRED
   SERVER_ERROR
  ```

- response

  This tag imports the **common** response codes, plus these response codes:

  ```
   DOCUMENT_FOLLOWS
   MOVED
   REDIRECT
   USE_LOCAL_COPY
   BAD_REQUEST
   BAD_GATEWAY
   RESPONSE_CODES
   NOT_IMPLEMENTED
   CONTINUE
   NOT_AUTHORITATIVE
  ```

  **CONTINUE** and **NOT\_AUTHORITATIVE** are aliases for **DECLINED**.

- methods

  This are the method numbers, commonly used with the Apache **method\_number** method.

  ```
   METHODS
   M_CONNECT
   M_DELETE
   M_GET
   M_INVALID
   M_OPTIONS
   M_POST
   M_PUT
   M_TRACE
   M_PATCH
   M_PROPFIND
   M_PROPPATCH
   M_MKCOL
   M_COPY
   M_MOVE
   M_LOCK
   M_UNLOCK
  ```

- options

  These constants are most commonly used with  the Apache **allow\_options** method:

  ```
   OPT_NONE
   OPT_INDEXES
   OPT_INCLUDES
   OPT_SYM_LINKS
   OPT_EXECCGI
   OPT_UNSET
   OPT_INCNOEXEC
   OPT_SYM_OWNER
   OPT_MULTI
   OPT_ALL
  ```

- satisfy

  These constants are most commonly used with  the Apache **satisfies** method:

  ```
   SATISFY_ALL
   SATISFY_ANY
   SATISFY_NOSPEC
  ```

- remotehost

  These constants are most commonly used with  the Apache **get\_remote\_host** method:

  ```
   REMOTE_HOST
   REMOTE_NAME
   REMOTE_NOLOOKUP
   REMOTE_DOUBLE_REV
  ```

- http

  This is the full set of HTTP response codes: (NOTE: not all implemented here)

  ```
   HTTP_OK
   HTTP_MOVED_TEMPORARILY
   HTTP_MOVED_PERMANENTLY
   HTTP_METHOD_NOT_ALLOWED
   HTTP_NOT_MODIFIED
   HTTP_UNAUTHORIZED
   HTTP_FORBIDDEN
   HTTP_NOT_FOUND
   HTTP_BAD_REQUEST
   HTTP_INTERNAL_SERVER_ERROR
   HTTP_NOT_ACCEPTABLE
   HTTP_NO_CONTENT
   HTTP_PRECONDITION_FAILED
   HTTP_SERVICE_UNAVAILABLE
   HTTP_VARIANT_ALSO_VARIES
  ```

- server

  These are constants related to server version:

  ```
   MODULE_MAGIC_NUMBER
   SERVER_VERSION
   SERVER_BUILT
  ```

- config

  These are constants related to configuration directives:

  ```
   DECLINE_CMD
  ```

- types

  These are constants related to internal request types:

  ```
   DIR_MAGIC_TYPE
  ```

- override

  These constants are used to control and test the context of configuration directives.

  ```
   OR_NONE
   OR_LIMIT
   OR_OPTIONS
   OR_FILEINFO
   OR_AUTHCFG
   OR_INDEXES
   OR_UNSET
   OR_ALL
   ACCESS_CONF
   RSRC_CONF
  ```

- args\_how

  ```
   RAW_ARGS
   TAKE1
   TAKE2
   TAKE12
   TAKE3
   TAKE23
   TAKE123
   ITERATE
   ITERATE2
   FLAG
   NO_ARGS
  ```

## Misuses

You should be aware of the issues relating to using constant subroutines in Perl. For example this:

```
  $r->custom_response(FORBIDDEN => "File size exceeds quota.");
```

will not set a custom response for `"FORBIDDEN"`, but for the string `"FORBIDDEN"`, which clearly isn't what is expected. You'll get an error like this:

```
  [Tue Apr 23 19:46:14 2002] null: Argument "FORBIDDEN" isn't
  numeric in subroutine entry at ...
```

Therefore, the best solution is not to use the hash notation for things that don't require it:

```
  $r->custom_response(FORBIDDEN,  "File size exceeds quota.");
```

Another important note is that instead of using HTTP codes, you should use designed for that purpose constants. Therefore, this is wrong:

```
  sub handler { return 200; }
```

The correct use is:

```
  use Apache::Constants qw(OK);
  sub handler { return OK; }
```

Also remember that `"OK != HTTP_OK"`.

## AUTHORS

Doug MacEachern, Gisle Aas and h2xs