Added gzip compression check

gzip-compression-check.php

@@ -0,0 +1,65 @@
+<?php
+/* 
+ * Gzip Compression Detector
+ * Author: Billy Brawner <billybrawner@gmail.com>
+ * License: MIT
+ * Use: php gzip-compression-check.php example.com
+ */
+
+# First, check to make sure that a URL was passed in as the first argument
+if (isset($argv[1])) {
+	$url = $argv[1];
+} else {
+	die("Please pass in a URL as the first argument");
+}
+
+# If it was, then make sure that it's a string, before checking to make sure that it's a URL
+if (gettype($url) !== "string") {
+	die("There was an error processing the URL you entered. Please try again.");
+} else {
+	if (!preg_match("/^(https?:\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?$/", $url)) {
+		die("The value entered does not appear to be a URL. Please try again.");
+	}
+}
+
+# Set the options for the cURL connection to only get the header and return its value.
+$ch = curl_init();
+curl_setopt_array($ch, [
+	CURLOPT_URL => $url,
+	CURLOPT_HEADER => true,
+	CURLOPT_NOBODY => true,
+	CURLOPT_RETURNTRANSFER => true,
+	CURLOPT_HTTPHEADER => ["Accept-Encoding: gzip"]
+]);
+
+# Store the value of the header for use later.
+$result = curl_exec($ch);
+curl_close($ch);
+
+# Begin parsing the data from the header.
+$data = explode("\n", $result);
+$headers = [];
+
+# Store the data in key => value pairs for easy access.
+foreach ($data as $index => $info) {
+	if ($info == "") {
+		continue;
+	}
+	$info = explode(":", $info);
+	if (count($info) > 1) {
+		$index = trim($info[0]);
+		$info = trim($info[1]);
+	}
+	$headers[$index] = $info;
+};
+
+# Report the results.
+if (isset ($headers["Content-Encoding"])) {
+	if ($headers["Content-Encoding"] == "gzip") {
+		echo "Gzip compression is enabled";
+	} else {
+		echo "Gzip compression is not enabled";
+	}
+} else {
+	echo "Content-Encoding header is not set. Cannot determine if gzip copmression is enabled.";
+}