sed(1posix) - stream editor
-e  script
       Add  the  editing  commands  specified  by  the script option-argument to the end of the script of
       editing commands. The script option-argument shall have the same properties as the script operand,
       described in the OPERANDS section.
-f  script_file
       Add the editing commands in the file script_file to the end of the script.
-n     Suppress  the  default output (in which each line, after it is examined for editing, is written to
       standard output). Only lines explicitly selected for output are written.