CSF port change

#!/bin/bash

number=$((RANDOM%30000+15000))

echo "New SSH port is "$number

if [[ -d "/etc/csf" ]];then
    in_good="TCP_IN = \"20,21,"
    good1=$in_good$number
    eval "sed -i 's/TCP_IN = \"20,21,22,/$good1,/g' csf.conf"
    out_good="TCP_OUT = \"20,21,"
    good2=$out_good$number
    eval "sed -i 's/TCP_OUT = \"20,21,22,/$good2,/g' csf.conf"
    echo "Port opened in CSF"
else
    echo "CSF not detected"
fi