How to make a persistent connection to a web url in php?

Question

I am trying to make a persistent connection to a weburl and read the response from the url every moment (Connection will not be disconnected).

Looking for something like this.

connection = connect("http://www.ibm.com?id=test"); while(connection has response){ //do something with the response until the connection in forcefully closed }

I had a look into pecl_http library. But this will not serve the purpose. Can we use curl to make a persistent connection to a web url?

Or is it something which is not supported in php?

Will the remote server keep streaming an endless HTTP response body…? HTTP doesn't seem like the best protocol for this, rather a web socket would be for streaming data. — deceze, Apr 11 '18 at 15:12
Persistent connection doesn't mean `"hey, something changed, here's the content"`. How well do you understand HTTP protocol? — N.B., Apr 11 '18 at 15:22
@deceze The API has a web socket and it stream data using https protocol. How do I go about it then? Create a web socket in my php application and then connect to the url? — Resna, Apr 11 '18 at 16:48
So you really want to create a *web socket* connection, yes? — deceze, Apr 11 '18 at 18:28

score 0 · Answer 1 · answered Apr 11 '18 at 15:16

0

Look how http protocol works. It's not possible to have persistent connection and receive event when content is changed. You can use websockets or long-polling. Check this library found on github https://github.com/panique/php-long-polling

answered Apr 11 '18 at 15:16

stalwart

78
8

It's certainly *possible*, it's just a bad use of HTTP and not very typical… – deceze Apr 11 '18 at 15:29
what the f are you smoking? it's fully possible to keep pushing data to a single http connection indefinitely. it's not gonna be easy if you're pushing to a web browser tho, cus of the caching n stuff the web browser is doing. but with something like curl, it's no problem. – hanshenrik Apr 12 '18 at 09:08

hanshenrik · Answer 2 · 2018-04-12T09:34:15.777

use the socket api.

$sock=socket_create(AF_INET,SOCK_STREAM,SOL_TCP);
socket_connect($sock,"www.ibm.com",80);
$data=implode("\r\n",array(
'GET /?id=test HTTP/1.0',
'Host: www.ibm.com',
'User-Agent: PHP/'.PHP_VERSION,
'Accept: */*'
))."\r\n\r\n";
socket_write($sock,$data);
while(false!==($read_last=socket_read($sock,1))){
   // do whatever
    echo $read_last;
}
var_dump("socket_read returned false, probably means the connection was closed.",
"socket_last_error: ",
socket_last_error($sock),
"socket_strerror: ",
socket_strerror(socket_last_error($sock))
);
socket_close($sock);

How to make a persistent connection to a web url in php?

2 Answers2