kml.pl: Implement set operation

kml.pl

@@ -61,7 +61,27 @@ elsif ($mode eq 'remove')
 
 elsif ($mode eq 'set')
 {
-    say "Set mode";
+    my ($name, $coordinates) = @ARGV;
+    unless (defined($name) && defined($coordinates))
+    {
+        say "Not enough args for set operation";
+        USAGE(1);
+    }
+    $name = to_id($name);
+    my ($placemark) = $xpc->findnodes("//k:Placemark[\@id=\"$name\"]");
+    if(defined($placemark))
+    {
+        my ($coordinates_node) = $xpc->findnodes("./k:Point/k:coordinates", $placemark);
+        my ($description_node) = $xpc->findnodes("./k:description", $placemark);
+        $coordinates_node->firstChild()->setData($coordinates);
+        $description_node->firstChild()->setData($coordinates);
+        print $dom->toString(1);
+    }
+    else
+    {
+        say "$name was not found in $filename";
+        exit(1);
+    }
 }
 
 else