xcode-select --install command failed to execute
I want to install Macports on Mavericks according to this page: http://trac.macports.org/wiki/MavericksProblems
But I can't run this command from terminal: xcode-select --install
It gives an error message: Can't install the software because it is not currently available from the Software Update server.
Anyone can help me find out what's the problem here? How else can I install Macports?
In addition, is there anyway that I can check that the command line tools are correctly installed in Mavericks? I'm using Xcode 5.
Thank you!
MacBook Pro with Retina display, OS X Mavericks (10.9)