title: php: pushing new data on server-side event
body: <p>Web development being completely new to me, this may be easy to find online but I might lack the technical jargon in this area...</p>
  
  <p>I need to display some data on a linux-device that also runs a webserver, so I figured the easiest way would probably be to do this in a browser. The data might change due to (physical) interaction with the device: it has external push-buttons attached. I need the data on the webpage to change instantly when a button is pressed, so that the user sees the values change immediately when he presses a button.</p>
  
  <p>This might be complete and utter nonsense, but is it possible to have the program that watches for button-presses pipe its output somewhere and have a piece of php respond to this? </p>
  
  <p>A sub-optimal solution would be to have a piece of client-side javascript with a timer that periodically "calls" (?) a piece of php. I don't like this solution because you either reload ad nauseam to minimize delays, or you'll notice lag in the response to the button-presses.</p>