":>" 여기서 뭐 하는 거야?

몇몇 포스트 스크립트를 봤어요

    # setting wget options
    :> wgetrc
    echo "noclobber = off" >> wgetrc
    echo "dir_prefix = ." >> wgetrc
    echo "dirstruct = off" >> wgetrc
    echo "verbose = on" >> wgetrc
    echo "progress = dot:default" >> wgetrc
    echo "tries = 2" >> wgetrc

여기서 뭐 하는 거야 :>?