The Shell Options panel is obtained from the Shell button in the Tools menu of the Tool Control window. The panel can control the values of internal variables used to define behavior of the WRspice shell. The shell is similar to the UNIX C-shell, and many of the variable names may be familiar from that context. These variables can also be set with the set command, though the panel may provide a more convenient interface.
Pressing the Help button pops up a window containing a listing of the variables which can be set with the panel. Clicking on a word in the listing will bring up the help viewer with a description of that variable.
Each variable has its own ``box'' in the panel. This box contains a Set button, and optionally a Def button and a text input area. The text input area can take several forms, depending on the type of variable: string, integer, or real. Boolean variables have only the Set button. Text can be entered into the area, or in some cases the up/down arrows to the right of the text area can be clicked to adjust the text.
When the Set button is active, the variable is set to the value shown in the text area (if any), and the text area is frozen, i.e., can't be edited. The text area can be changed only with the Set button inactive, in which case the value in the text area is arbitrary. The value is only known to WRspice when the Set button is active, in which case the variable should appear in the listing brought up by the Variables button in the Tools menu in the Tool Control window.
The Def button will enter the default value for the variable into the text area. This button becomes active if the text area is modified.