hugs -i +g +h30Kto start the interpreter with the i option (import chasing) disabled, the g option (garbage collector messages) enabled, and with a heap of thirty thousand cells. As this example suggests, many of the options are toggles, meaning that they can either be switched on (by preceding the option with a + character) or off (by using a - character). Options may also be grouped together. For example, hugs +stf -le is equivalent to hugs +s +t +f -l -e.
Option settings can be specified in a number of different ways---the HUGSFLAGS environment variable, the Windows registry, the command line, and the :set command---but the same syntax is used in each case. To avoid any confusion with filenames entered on the command line, option settings must always begin with a leading + or - character. However, in some cases---the h, p, r, P, and E options---the choice is not significant. With the exception of the heap size option, h, all options can be changed while the interpreter is running using the :set command. The same command can be used (without any arguments) to display a summary of the available options and to inspect their current settings.
The complete set of Hugs options is described in the sections below.
Set search path -P<path>
Set editor -E<cmd>
Print statistics +s,-s
Print type after evaluation +t,-t
Terminate on error +f,-f
Garbage collector notification +g,-g
Literate modules +l,-l,+e,-e
List files loaded +w,-w
Display dots while loading +.,-.
Load Quietly +q,-q
Use "show'' to display results +u,-u
Detailed kind errors +k,-k
Import chasing +i,-i
Set heap size -h<size>
Set prompt -p<string>
Set repeat string -r<string>