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--- uphp:functions:mqtt_subscribe [2017/09/27 10:46]
admin
+++ uphp:functions:mqtt_subscribe [2019/11/29 05:02]
admin
@@ Line 30: / Line 30: @@
 <code php>
 <?
 // Use the # as a wildcard so any messages to /cluster/1/ or its sub channels will be received
@@ Line 36: / Line 35: @@
 ?>
 </code>
+====Example Callback====
+Callbacks can use the ''stdin'' file to read input.  Use fgets() to get the first line, which will be the full channel.  The following lines will be the data received.
+<code php>
+<?
+$f=fopen("php://stdin","r");
+$st=fgets($f);
+$msg=fgets($f);
+$response="";
+if (substr($msg,0,3)=='get') {
+	$variable=substr($msg,4,strlen($msg)-3);
+	$response=$variable.":".$_GLOBALS[$variable];
+}
+if (strpos($st,getmac()) || strpos($st,'/all')) {
+	if (strpos($st,"get")) {
+        mqtt_publish("/cluster/1/ret/".getmac(),$response);
+	} else {
+		if (strpos($st,"ret")) {
+			print("Notification was properly posted");
+		}
+	}
+}
+?>
+</code>
+====Note=====
+On WattmonPRO & MINI the maximum packet size is 128 bytes.  On WattmonMega, M2 & Mini2 the maximum packet size is 2048 bytes.
 ====See Also====

Wattmon Documentation Wiki