hi,i dont know much about programing so i need your help.I have a small web server using arduino uno /ethernet and some relays for a small home automation.I can open doors,and control some lights in my house.
A server serves up answers in response to a client request.
A client makes requests.
It appears that you have a server.
The next step i need to do is using arduino and a button switch on a digital port to send an url to a remote device so i can control something over the internet,for example ,when i press the button and set the digital port to "high" ,an url like "http://myoffice.ip/?lightsoff" be sent to my office arduino web server.
The same Arduino that is the server? Or, a different one?
A client, which is what the Arduino with switch would be, does not "send a URL". It makes a GET request of a server. In your example, the server would be identified as "myoffice.ip", and the GET request would be "GET /?lightsoff HTTP/1.1".