How to save an output of airodump-ng to a file?

I've tried to get a file from airodump-ng via redirecting a output stream via: airodump-ng mon0 2>&1 | tee file.txt but this appends to a file rather than rewrites it. So after that I've tried to redirect an output to other output stream via a fifo pipeline: First terminal: mkfifo fifo1 echo "while [ 1 ]; do cat ~/fifo1 2>&1 | tee file.txt done" > readfifo.sh chmod +x readfifo.h xterm -e readfifo.sh Second terminal: airodump-ng mon0 2>&1 > fifo1 And in the result we have an appending file.txt, but why ? How to have only the output of a terminal in the file, but not append to it ? Is it possible to filter an output of airodump-ng while writeting to a file ? Best regards, V7