isbiosoruefi.sh

#!/bin/bash                                                                                                                                                  
                                                                                                                                                             
echo "Show running mode (UEFI or BIOS) of your system."  
echo "@see https://askubuntu.com/a/947856"
echo ""                                                                                                                                                      
mode=$(test -d /sys/firmware/efi && echo UEFI || echo BIOS)                                                                                                  
echo "System runnging in mode: $mode"