Enter filters for extract command
This is the command for entering filters to be passed to EXTRACT. Each filter command builds on the list set up by the previous ones. For all the filter commands, a file name proceeded by a - indicates that that file should be removed from the list.
There are five filter_what values (besides quit), INTENSITY, TIME, REGION and PHA and PHASE, which will be treated in their own subheadings.
Syntax:
xsel > filter <filter_what>