irb> p "ね\001こ\t大\025す\177き\n".gsub(/[[:cntrl:]]/){''} == "ねこ大すき"
true
irb> p "ね\001こ\t大\025す\177き\n".gsub(/(?![[:space:]])[[:cntrl:]]/){''} == "ね こ\t大すき\n"
true