php socket send data and then receive data

Question

i want to create the following:

1.open a connection to a udp or tcp
2.send somme data to the selected IP address
3.receive the data from the selected ip address
4.capture the receive data inside a variable.

The task is: the user sends a command to a device the device responds and i do something with the data received. I have the following code but i think i need a loop or a while function to wait for the received data. The user sends the command but if the response is not instantaneous i have to wait for it ..or check for it. i am using html , css and PHP here is the code i use.

 <?php

    if(isset($_POST['btn_cmd']))
    {
        $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
        socket_bind($sock, '127.0.0.1', 23);

        $msg = "AT+BC=RTIME";
        $len = strlen($msg);

        socket_sendto($sock, $msg, $len, 0, '127.0.0.1', 23);
        $from = '';
        $port = 0;
        socket_recvfrom($sock, $buf, 30, 0, $from, $port);      
 ?>

    <input type="text" 
           name="name3" 
           size="25" 
           maxlength="50" 
           value="<?php echo($buf); ?>">

 <?php
        socket_close($sock);
    }
 ?>

can u please help me with an example for the receive part i use this new code:

$out='';
        echo "Reading response:\n\n";
        //$out = socket_read($socket, 2048,PHP_NORMAL_READ) ;
        while ($out=socket_recv($socket, $buf, 2048,PHP_NORMAL_READ)) {

            echo "mesaj out:" .$out;

the problem is that i need to wait for the response and the code above is not working. i think i need a while function or something to do a looop and wait for the response and then close that loop. and i don;t know how to do that. i;ve tried all the receive and listening php functions.all i need is a small example to start from.

Jay Blanchard · Accepted Answer · 2015-11-05 20:14:12Z

1

Your question is a bit broad, but the upshot is that you need to put a listener in a loop. Here is an example with an infinite loop:

// create a UDP socket
if(!($sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP))) {
    $errorcode = socket_last_error();
    $errormsg = socket_strerror($errorcode);

    file_put_contents('/var/log/udp.log', "Couldn't create socket: [$errorcode] $errormsg\n", FILE_APPEND);
}

// bind the source address
if( !socket_bind($sock, $localIP, 23) )
{
    $errorcode = socket_last_error();
    $errormsg = socket_strerror($errorcode);

    file_put_contents('/var/log/udp.log', "Could not bind socket: [$errorcode] $errormsg\n", FILE_APPEND);
}

// do some communication, this loop can handle multiple clients
while(1)
{
    // receive some data
    $r = socket_recvfrom($sock, $buf, 512, 0, $remote_ip, $remote_port);
    $parsed_data = json_decode($buf); // assumes data is JSON
    $now = date('Y-m-d H:i:s');
    file_put_contents('/var/log/udp.log', "$now\t$buf\n", FILE_APPEND);

    // do stuff with JSON you received

}

 socket_close($sock);

answered Nov 5, 2015 at 20:14

Jay Blanchard

34.5k17 gold badges82 silver badges130 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Daniel Serban Over a year ago

i have tried the exemple above . i now can send the command ! but when i try to receive it goes into an infinite loop ?

Jay Blanchard Over a year ago

while(1) sets up an infinite loop as a listener. Any command that you send will have to be done outside of the loop or you will have to add logic to send the commands as you need them @DanielSerban

Daniel Serban Over a year ago

Jay .first of all thank you for your answer. i am trying to use this code: ------ $out=''; echo "Reading response:\n\n"; //$out = socket_read($socket, 2048,PHP_NORMAL_READ) ; while ($out=socket_read($socket, 2048,PHP_NORMAL_READ)) { echo "mesaj out:" .$out; } ------ but with no succes. can you please provide me with an example.

Jay Blanchard Over a year ago

Please do not dump code in comments. Edit your original post to add any further information and do not use an answer to show updates.

Daniel Serban Over a year ago

sorry . please find my question above.

Collectives™ on Stack Overflow

php socket send data and then receive data

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related