tfc_say(" count=val: process only these val bytes, both input and output.");
tfc_say(" ftrunc=val: truncate output file to these val bytes before closing it.");
tfc_say(" ftrunc=tail: truncate output's tail, leaving only processed data.");
tfc_say(" count=val: process only these val bytes, both input and output.");
tfc_say(" ftrunc=val: truncate output file to these val bytes before closing it.");
tfc_say(" ftrunc=tail: truncate output's tail, leaving only processed data.");