Add php example script (closes #2087)

Co-authored-by: AutomGuy <AutomGuy@users.noreply.github.com>

examples/rtl_433_custom.php

@@ -0,0 +1,108 @@
+#!/usr/bin/php
+<?php
+/*
+Short example of an UDP server written in PHP for rtl_433.
+
+You need to have `php_cli` installed.
+
+To run this as service use these systemd service files for
+ubuntu, lubuntu, xubuntu, debian, ubuntu core and so on.
+
+## Service file to start the rtl_433 process
+
+
+[Unit]
+Description=rtl433 udp service
+After=network.target
+[Service]
+Restart=always
+RestartSec=5
+RemainAfterExit=no
+User=root
+ExecStart=/bin/bash -c "/usr/bin/rtl_433 -f 433920000 -f 433920000 -H 120 -F syslog:127.0.0.1:1433"
+
+[Install]
+WantedBy=multi-user.target
+
+
+## Service file to start the php udp server
+
+
+[Unit]
+Description=syslog 433 udp service
+After=network.target
+StartLimitIntervalSec=0
+[Service]
+Type=simple
+Restart=always
+RestartSec=1
+User=root
+ExecStart=/usr/bin/php /home/user/rtl_433/examples/rtl_433_custom.php "0"
+
+[Install]
+WantedBy=multi-user.target
+*/
+
+error_reporting(E_ALL | E_STRICT);
+
+//switch on debug mode
+$debug = "1";
+if (sizeof($argv) > 1)
+{
+    $debug  = $argv[1];
+}
+//udp server IP and Port for listen
+$UDP_IP = "127.0.0.1";
+$UDP_PORT = 1433;
+//create socket and bind them
+$socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
+socket_bind($socket, $UDP_IP, $UDP_PORT);
+//init of this variables
+$from = '';
+$port = 0;
+
+//use the output of rtl_433 -f 433920000 -f 433920000 -H 120 -F syslog:127.0.0.1:1433"
+//returns the json payload
+function parse_syslog($line)
+{
+    //Try to extract the payload from a syslog line.//
+    $line = mb_convert_encoding($line, "ASCII");
+
+    if (startsWith($line,"<"))
+    {
+        //fields should be "VER", timestamp, hostname, command, pid, mid, sdata, payload
+        $fields = explode(" ",$line, 8);
+        $line = $fields[7];
+    }
+    return $line;
+}
+
+//server main loop
+for (;;)
+{
+    //read from $socket into $line
+    socket_recvfrom($socket, $line, 1024, 0, $from, $port);
+    try
+    {
+        //parse $line -> returns the json payload
+        $line = parse_syslog($line);
+
+        /*
+        do something with content of $line
+        for example decode $line into a array
+        $arr = json_decode($line,true);
+
+        do something with that array and
+        puted into a file as json
+
+        file_put_contents('test.json', json_encode($arr, JSON_PRETTY_PRINT);
+        */
+    }
+    catch (Exception $e) {
+        echo "---------------------------------------------\n";
+        echo 'Exception intercepted: ', $e->getMessage(), "\n";
+        echo "------------------------------------------- -\n";
+    }
+}
+?>
+