Internal Variables

There are numerous system variables strewn throughout Darwin. A system variable is assigned a value by using the Set function. This function accepts as a parameter any one of the options in Table . This is followed by equal sign (=) which is, in turn, followed by a value for that option. The command returns the previous value assigned to this variable.

> x := Set(screenwidth=5);            # things get really narrow now
> print('Heidi comes from Heidiland');
> Set(screenwidth=x);                 # everything back to normal

Table: Options for the Set function.

1.1 

Table: Options for the Set function.

Name	Type	Description
echo	$0\ldots$	Sets the level of input/output information
		displayed.
gc	integer	Sets the frequency (in words allocated) for
		garbage collection.
mapsize	integer	Sets the minimum size (in chars) required for
		Darwin to build a .map file.
plotdevice	printing style 1	Sets the protocol for subsequent print files.
plotoutput	filename	Specifies where files contain plotter code is sent.
printgc	boolean	Toggles displaying garbage collection information.
printlevel´	integer	Sets the amount of information printed out
		which is during execution.
profile	boolean	Toggles printer/plotter profile mode
prompt	string	Sets the Darwin prompt.
quiet	boolean	Toggles the suppression of output.
server	boolean	Places Darwin in server mode.
screenwidth	posint	Sets the width of a line for all subsequent output.