send TCP message in loop - php

Question

I am trying to send a tcp message in a script with reading from stdin in a loop. The problem is that the server only receives the connection, not the message. Everything works if I remove the loop.
#!/bin/php
<?php
use React\Socket\ConnectionInterface;
use React\Socket\TcpConnector;
require dirname(__DIR__) . '/vendor/autoload.php';
while (true) {
$line = trim(fgets(STDIN));
echo "try to send $line\n";
try {
$client = new TcpConnector();
$client
->connect('tcp://127.0.0.1:8080')
->then(
function (ConnectionInterface $connection) use ($line) {
echo "fulfilled\n";
$connection->write($line);
$connection->end();
},
function () {
echo "rejected\n";
},
function () {
echo "onProgress\n";
}
);
} catch (Throwable $e) {
echo $e->getMessage();
}
// break; // work with this break
}
with this code, when I send
./console.php
foo
try to send foo
bar
try to send bar
On the server side :
new connection: tcp://127.0.0.1:40936
new connection: tcp://127.0.0.1:40944
If I remove the loop :
./console.php
foo
try to send foo
fulfilled
Note: work great with telnet

Answer 1

Ok, some question about ratchet in a loop tel me the answer.
The loop wait the end of script before run... It never happen in this case.
We need to run $loop->run() at the right time.
The corrected code :
#!/bin/php
<?php
use React\EventLoop\Loop;
use React\Socket\ConnectionInterface;
use React\Socket\TcpConnector;
require dirname(__DIR__) . '/vendor/autoload.php';
while (true) {
$line = trim(fgets(STDIN));
echo "try to send $line\n";
try {
$loop = Loop::get();
$client = new TcpConnector($loop);
$client
->connect('tcp://127.0.0.1:8080')
->then(
function (ConnectionInterface $connection) use ($line) {
echo "fulfilled\n";
$connection->write($line);
$connection->end();
},
function () {
echo "rejected\n";
},
function () {
echo "onProgress\n";
}
);
$loop->run();
} catch (Throwable $e) {
echo $e->getMessage();
}
}

Answer 2

I think your solution fits your use case, just beware that $line = trim(fgets(STDIN)); will always block your code, because it waits on your input.
To simplify your example a bit more:
#!/bin/php
<?php
use React\EventLoop\Loop;
use React\Socket\ConnectionInterface;
use React\Socket\TcpConnector;
require dirname(__DIR__) . '/vendor/autoload.php';
while (true) {
$line = trim(fgets(STDIN));
echo "try to send $line\n";
$loop = Loop::get();
$client = new TcpConnector($loop);
$client
->connect('tcp://127.0.0.1:8080')
->then(
function (ConnectionInterface $connection) use ($line) {
echo "fulfilled\n";
$connection->write($line);
$connection->end();
},
function () {
echo "rejected\n";
}
);
$loop->run();
}
Your try-catch does actually nothing here, so you won't need it. This is because of the promise behavior in ReactPHP. If an exception is thrown inside a promise, you can only see it if you explicitly catch it or define a behavior if the promise gets rejected, e.g. like this:
// your reject
function () {
echo "rejected\n";
}
// my suggested reject
function (Exception $error) {
echo 'Error: ' . $error->getMessage() . PHP_EOL;
}
You can also take a look at https://github.com/clue/reactphp-stdio as an alternative approach for your use case.