move lookup to a sub command and add mem usage to the bot stats command

src/main/java/cc/fascinated/bat/common/StringUtils.java

@@ -37,4 +37,18 @@ public class StringUtils {
         }
         return inputString;
     }
+
+    /**
+     * Formats bytes into a human-readable format
+     *
+     * @param bytes the bytes
+     * @return the formatted bytes
+     */
+    public static String formatBytes(long bytes) {
+        int unit = 1024;
+        if (bytes < unit) return bytes + " B";
+        int exp = (int) (Math.log(bytes) / Math.log(unit));
+        char pre = "KMGTPE".charAt(exp-1);
+        return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre);
+    }
 }