Run 'echo -t' without the patch will get the result: echo: Unknown flag - '-t' The expected result is to display '-t' literally. This patch adds special handle for 'echo'. 'echo' will not use the general parameter parsing library. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com> Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>