update some for file

Author: inhere

src/File.php

@@ -366,6 +366,20 @@ public static function streamReadAll($stream, int $length = -1, int $offset = -1
         return (string)stream_get_contents($stream, $length, $offset);
     }
 
+    /**
+     * Read one char from stream.
+     *
+     * @param $stream
+     *
+     * @return string
+     */
+    public static function streamReadChar($stream): string
+    {
+        self::assertReadableStream($stream);
+
+        return (string)stream_get_contents($stream, 1);
+    }
+
     /**
      * Retrieves header/meta data from streams/file pointers
      *