curl can do one change directory (CWD) command for every individual directory
    down the file tree hierarchy. If the full path is ,
    that method means doing three CWD commands before asking for the file.txt
    file to get transferred. This method thus creates quite a large number of
    commands if the path is many levels deep. This method is mandated by an early
    spec (RFC 1738) and is how curl acts by default:

    1. > CWD one
    3. < 250 OK. Current directory is /one/two
    4. > CWD three
    5. < 250 OK. Current directory is /one/two/three

    The opposite to doing one CWD for each directory part is to not change the
    directory at all. This method asks the server using the entire path at once
    and is thus very fast. Occasionally servers have a problem with this and it
    isn’t purely standards-compliant:

    This is the in-between the other two FTP methods. This makes a single CWD
    command to the target directory and then it asks for the given file:

    1. > CWD one/two/three
    2. < 250 OK. Current directory is /one/two/three
    3. > RETR file.txt