tail /var/log/proftpd/proftpd.log /var/log/proftpd/xfer.log -f | grep --line-buffered "192.168.0.1\|192.168.0.5" | sed -u -e 's/192.168.0.5/Petya/g'
tail /var/log/proftpd/proftpd.log /var/log/proftpd/xfer.log -f | grep "192.168.0.1\|192.168.0.5" | sed 's/192.168.0.1/Vasya/g' | sed 's/192.168.0.5/Petya/g'