[Vala] Help~ How to call system API like open() and socket()?

[GaoXianchao <gxcmaillist gmail com>]

Hi~
Today I found Vala. It's the dream language in my heart, I finally got it!
I want to use Vala to make my 3rd BitTorrent client.

My first BitTorrent Client is bitstormlite. It's using c++ & GTK2, already in Debian & Ubuntu.
My second BitTorrent Client is bitbox . It's based on java.

bitbox is easy to develop but need jvm and more memory. bitstormlite is fast but development using c++ is hard.

so I think Vala is my best selection. I have a question :
How to call system API like open() and socket()?

Thanks a lot!