How can I get a text file with contents like this `01:23:45:67:89:ab` into the variable `$LastMAC`? I already tried a few variations, with cat but not luck. I tried to use the LastMAC=$(cat LastMAC.txt, also tried to use LastMAC=`cat LastMAC.txt' and there is no error code, but the prompt just shows a blinking cursor, and does nothing.