8.6 Options

The FunnelWeb shell maintains three sets of command line options.

1. The set of options resulting from applying the operating system level command line arguments to the default option settings.
2. A set of shell options that prevail during the shell invocation.
3. The set of option values active during a particular invocation of FunnelWeb proper.

When FunnelWeb is invoked from the operating system with just +F, only the first of these three sets comes into existence. If the user invokes the FunnelWeb shell, the shell options come into existence and are initialized with the value of the first set. These shell options are used as the default for all subsequent fw commands. However, they can be altered using the script command set. If a fw command executed in a shell contains additional command line options, these override the shell options for that run, but do not change the shell options. An example follows:

$ fw +k +t            ! Original invocation from OS.
                      ! Options default with "+t".
FunnelWeb>fw sloth    ! Equivalent to fw sloth +t.
FunnelWeb>set -l      ! Change the l shell option.
FunnelWeb>fw sloth +q ! Equiv to fw sloth +t -l +q.
FunnelWeb>fw sloth    ! Equiv to fw sloth +t -l.

The existence of the shell option set means that the user can set up a set of defaults to be applied to all fw commands issued within the shell.