Apache HTTP Server Version 2.4

| Description: | Group authorization using plaintext files | 
|---|---|
| Status: | Base | 
| Module Identifier: | authz_groupfile_module | 
| Source File: | mod_authz_groupfile.c | 
| Compatibility: | Available in Apache 2.1 and later | 
This module provides authorization capabilities so that
    authenticated users can be allowed or denied access to portions
    of the web site by group membership. Similar functionality is
    provided by mod_authz_dbm.
Apache's Require
    directives are used during the authorization phase to ensure that
    a user is allowed to access a resource.  mod_authz_groupfile extends the
    authorization types with group and group-file.
    
Since v2.4.8, expressions are supported within the groupfile require directives.
This directive specifies group membership that is required for the user to gain access.
Require group admin
When this directive is specified, the user must be a member of the group assigned to the file being accessed.
Require file-group
| Description: | Sets the name of a text file containing the list of user groups for authorization | 
|---|---|
| Syntax: | AuthGroupFile file-path | 
| Context: | directory, .htaccess | 
| Override: | AuthConfig | 
| Status: | Base | 
| Module: | mod_authz_groupfile | 
The AuthGroupFile directive sets the
    name of a textual file containing the list of user groups for user
    authorization. File-path is the path to the group
    file. If it is not absolute, it is treated as relative to the ServerRoot.
Each line of the group file contains a groupname followed by a colon, followed by the member usernames separated by spaces.
      mygroup: bob joe anne
    
Note that searching large text files is very
    inefficient; AuthDBMGroupFile provides a much better performance.
Make sure that the AuthGroupFile is
      stored outside the document tree of the web-server; do not
      put it in the directory that it protects. Otherwise, clients may
      be able to download the AuthGroupFile.