Several methods of filtering the information before presentation are provided by Metafinger. In addition, each medium provides different presentation formats and parameters.
The primary form of filtering provided by Metafinger is removal of users which don't belong to one of the groups specified by the user. As described earlier (in Meta-Levels,) Metafinger knows about local groups of users. Whenever a name is provided to Metafinger, it checks to see if the name matches a local group. If so, or if multiple user names are being specified for a single finger server, the server is queried for all the users currently logged in, and the data returned is filtered to only keep information about users within the specified group(s).
Additional filters are provided:
The information about users who aren't currently active may be suppressed by selecting this filter. The definition of "currently active" is also user definable, by specifying the number of minutes considered reasonable.
Selecting this filter will tell Metafinger to only show one login per user per computer system. If an active login is found, it is shown, otherwise the first login encountered is presented.
Although appearing to be a filter, this actually queries the finger server to only provide information about users local to that computer system, not the entire site. This is only applicable for systems which are running a site wide finger server (such as GNU or Metafinger.) This was supported as a "filter" in order to allow a listing of local users to be limited to a particular group.
If a listing of ALL the users at a single machine within a site is desired, it may also be obtained by specifying only the ".local" special user at the desired machine. This is the underlying mechanism used by server to support the local search filter.
Although most presentation parameters are medium dependant, in all cases the data is sorted before bing presented. This sorting may be performed using one of several criteria:
Ideally, the text presentation would be specified by a function written in a text formatting language, such as Adobe Postscript. The drawbacks to this approach are the learning curve required for even minor changes in the output, and the complexity of supporting an interpreter for such a language. Instead, the amount of control over the text presentation is limited to selecting a pre-designed format (at the user interface), and modifying a small set of parameters for each format.
While there are many parameters of the different text formats that may be adjusted, they are not accesible through the user interface. Instead, they must be specified in a user's profile , in order to keep the interfaces simple.
The video presentation is controlled almost entirely by a script provided by the user, which is provided with the interpreted, filtered, and sorted finger data and a runtime environment. The structure of this file is detailed in Metafinger's online help . If a user has no video configuration file, a system default is used.
The ability to specify a quarter size (half in each dimension) version of the image is provided at the user interface. This allows quicker image transfer over slower network connections.