Apache::Constants - Constants defined in apache header files

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

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

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

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 CWFORBIDDEN, but for the string CW"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 CWOK != HTTP_OK.

Doug MacEachern, Gisle Aas and h2xs