GKS Names

A GKS workstation name is a character string that represents a graphics device that may be opened and manipulated using GKS. The simplest way to get a list of valid workstation names is to run the demonstration program). When you supply a workstation name to a program that uses GNS (either directly or indirectly via a high level graphics package) you can abbreviate the name provided that the abbreviation is not ambiguous. You can also supply a environment variable that translates to a workstation name; this can be used to create ``nicknames'' for devices that you use frequently.

Each workstation name identifies a device type and may also identify a particular device (or file). For example, the workstation name cifer_t5 might translate to 801 (the GKS workstation type for a Cifer T5 terminal), while ps_l might translate to 2700 and gks74.ps (the GKS workstation type and the usual file name of a landscape orientation PostScript printer file).

If a name translates to just a workstation type then a ``default'' device is used. All device types have a default device name associated with them, and this is most important for terminals where the default is the terminal from which the program is being run. In this case the default device name depends on which terminal is being used.

The device name implied by a workstation name can be overridden by appending a semicolon followed by a new device or file name to the workstation name. For example, the name ps_l;plot.ps would use plot.ps instead of gks74.ps.

If an explicit device name is supplied there are no checks made to ensure that the device is the right type; attempting to use the wrong type will either cause the attempt to open the GKS workstation to fail or garbage to be sent to the device.

An application program can also override the device name implied by a workstation name; if it does, the program's documentation should make this clear. An application cannot override a device name which is supplied explicitly as part of a workstation name.

It is also possible to specify an explicit GKS device type and connection identifier as a pair of integers separated by a comma, space or underscore. If the connection identifier is omitted, it defaults to zero.

Finally, a workstation name can be an environment variable that translates to a valid workstation name (which can be another environment variable). Any explicit device name is removed before the translation is attempted and the first device name encountered is the one that is used; any subsequent device names are ignored. Environment variable translation continues recursively until either no translation is found or the resulting name begins with ``GKS_''.