(PHP 4, PHP 5, PHP 7, PHP 8)
connection_status — Liefert den Verbindungsstatus als Bitfeld
Diese Funktion besitzt keine Parameter.
 Der Verbindungsstatus als Bitfeld, das zusammen mit den
 CONNECTION_* -Konstanten
 verwendet werden kann, um den Verbindungsstatus zu ermitteln.
 
Notice !
if you running a loop (while, foeach etc..) you have to send something to the browser to check the status.
Example:
while(1){
 if (connection_status()!=0){
 die;
 }
}
doesnt work, if the user break/close the browser.
But a:
while(1){
 Echo "\n"; //<-- send this to the client
 if (connection_status()!=0){
 die;
 }
}
will work :)
i hope it will help some of you to safe some time :)
ToppiAs mentioned, this function returns a status bitfield to which there's a set of constants available. I don't know why those constants aren't actually listed. Although they're easy to guess, I think it's still worth listing them, it is documentation after all. This function has the ability to return integers 0 through 3 so there are 4 possible states.
The constants are as follows:
CONNECTION_NORMAL = 0
CONNECTION_ABORTED = 1
CONNECTION_TIMEOUT = 2
As a 4th state is possible and being a bitfield, this gives rise to CONNECTION_ABORTED|CONNECTION_TIMEOUT (or integer 3) can be used to check for aborted+timeout states.