Implement unpacking logic

core/05-functions.php

@@ -623,3 +623,26 @@ function email_users($usernames, $subject, $body)
 	}
 	return $emailsSent;
 }
+
+/**
+ * Recursively deletes a directory and it's contents.
+ * Adapted by Starbeamrainbowlabs
+ * @param	string	$path			The path to the directory to delete.
+ * @param	bool	$delete_self	Whether to delete the top-level directory. Set this to false to delete only a directory's contents
+ * @source https://stackoverflow.com/questions/4490637/recursive-delete
+ */
+function delete_recursive($path, $delete_self = true) {
+    $it = new RecursiveIteratorIterator(
+        new RecursiveDirectoryIterator($path),
+        RecursiveIteratorIterator::CHILD_FIRST
+    );
+    foreach ($it as $file) {
+        if (in_array($file->getBasename(), [".", ".."]))
+            continue;
+        if($file->isDir())
+            rmdir($file->getPathname());
+		else
+            unlink($file->getPathname());
+    }
+    if($delete_self) rmdir($path);
+}

core/07-unpack.php

@@ -0,0 +1,28 @@
+<?php
+
+// If the extra data directory:
+//  - doesn't exist already
+//  - has an mtime before that of this file
+// ...extract it again
+if(!file_exists($paths->extra_data_directory) || 
+	filemtime(__FILE__) > filemtime($paths->extra_data_directory)) {
+	if(file_exists($paths->extra_data_directory))
+		delete_recursive($paths->extra_data_directory, false);
+	else
+		mkdir($paths->extra_data_directory, 0700);
+	touch($paths->extra_data_directory);
+		
+	$temp_file = tmpfile();
+	$source = fopen(__FILE__, "r");
+	
+	fseek($source, __COMPILER_HALT_OFFSET__);
+	stream_copy_to_stream($source, $temp_file);
+	
+	$temp_filename = stream_get_meta_data($temp_file)["uri"];
+	
+	$extractor = new ZipArchive();
+	$extractor->open($temp_filename);
+	$extractor->extractTo($paths->extra_data_directory);
+	$extractor->close();
+	fclose($temp_file);
+}