param1=value1
param2=value2
param3=value3

file="./parameters.txt"

if [ -f "$file" ]
then
    echo "$file found."

    while IFS='=' read -r key value
    do
        key=$(echo $key | tr '.' '_')
        eval "${key}='${value}'"
    done < "$file"

else
    echo "$file not found."
fi

if [ -z ${param1} ]
then
    echo "Param1 is empty"; exit 1
fi