The idea is to connect PHP webpage and C program via TCP socket so, that webpage waits for connection from C program and receives data as soon as connection established. The code of PHP socket connection and data receiving is below:
PHP(socketRead.php):
$address = 'localhost';
$port = 5001;
if (($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) < 0) {
echo "Socket creation error";
}
else {
echo "Socket created <br/>";
}
if (($ret = socket_bind($sock, $address, $port)) < 0) {
echo "Host/port connection failed";
}
else {
echo "Host/port connection successful <br/>";
}
if (($ret = socket_listen($sock, 5)) < 0) {
echo "Socket error";
}
else {
echo "Waiting connection <br/>";
}
if (($msgsock = socket_accept($sock)) < 0) {
echo "Socket connection start error";
} else {
echo "Awaiting data <br/>";
}
//Connection established, reading data
if (false === ($buf = socket_read($msgsock, 1024))) {
echo "Read error";
} else {
echo "Data: ".$buf;
}
if (isset($sock)) {
socket_close($ret);
socket_close($sock);
}
echo "<br /> Socket closed";
To read data from socket dynamically I use jquery request.
Javascript(index.html):
function update_content() {
var request = $.get("socket/socketRead.php");
request.success(function(result) {
document.write(result);
});
}
update_content();
Worked great until I tried to add interval to read data repeatedly.
Javascript(index.html):
var timer = setInterval(function(){update_content();}, 1000);
The first connection/receiving is still works,but then I get "Connection refused" in C program when trying to connect again. Can you help me with this problem?
You could use SSE for that.
Server Sent Events
https://developer.mozilla.org/en-US/docs/Web/API/EventSource
this does not answer your php question .. but SSE it's made for what you are trying to do.
js
var sse=new EventSource("sse.php");
sse.onmessage=function(e){
console.log(e.data)
};
sse.php
function send($data){
echo "id: ".time().PHP_EOL;
echo "data: ".$data.PHP_EOL;
echo PHP_EOL;
ob_flush(); // clear memory
flush();
}
header('Content-Type: text/event-stream'); // specific sse mimetype
header('Cache-Control: no-cache'); // no cache
$address='localhost';$port=5001;
while(true){
$msg=($sock=socket_create(AF_INET,SOCK_STREAM,SOL_TCP))?'created':'error';
send("Socket creation ".$msg);
$msg=($ret = socket_bind($sock, $address, $port))?'connected':'refused';
send("connection ".$msg);
//....
// do the rest
//.....
sleep(10);
}
note1:Not sure if the php syntax is correct but it's just here to give you an idea.
Another example of sse .. 2nd part is also using json.