systemd-initctl.service, systemd-initctl.socket, systemd-initctl — /dev/initctl compatibility
systemd-initctl.service
systemd-initctl.socket
/usr/lib/systemd/systemd-initctl
systemd-initctl is a system service
    that implements compatibility with the
    /dev/initctl FIFO file system object, as
    implemented by the SysV init system.
    systemd-initctl is automatically activated on
    request and terminates itself when it is unused.