options:
    p: skript.admin                                 # Permission required for the command
    pm: &cYou don't have access to that command.    # Message sent if player's permission is insufficient
    failed: &cPlayer is offline.                    # Message sent if arg-1 is offline


command /openinv [<offlineplayer>]:
    permission: {@p}
    permission message: {@pm}
    trigger:
        set {_p} to arg 1 ? player
        if {_p} is offline:
            send "{@failed}"
        else:
            open {_p}'s inventory for player

command /openender [<offlineplayer>]:
    permission: {@p}
    permission message: {@pm}
    trigger:
        set {_p} to arg 1 ? player
        if {_p} is offline:
            send "{@failed}"
        else:
            open ender chest of {_p} to player