The postscript file contents are mostly commands and base64 or hex encoded
data. Text content is in general not available without removing
justification whitespace, i.e. extraction requires a postscript
interpreter.

run balooshow -x <ps-file> before
-> lots of garbage terms
balooctl clear <ps-file>; touch <ps-file>
run balooshow -x <ps-file> again
-> the terms are empty now, save the mimetype ("Mapplication Mpostscript")