Quickly create a nested folder structure via Terminal

  • I didn't know about:

        {A..C}{0..3}
    
    "This sequence creates every combination of A to C and 0 to 3—i.e. A0, A1, A2, A3, B0, B1, etc."

    And:

        echo {a..z..2}
        a c e g i k m o q s u w y
    
    "The ..2 bit tells the expansion to only output every second letter."