-c     Write to standard output; no files are changed.

-f     Do not prompt for overwriting files. Except when run in the background, if -f  is  not  given  the
       user shall be prompted as to whether an existing file should be overwritten. If the standard input
       is not a terminal and -f is not given, uncompress shall write a  diagnostic  message  to  standard
       error and exit with a status greater than zero.

-v     Write messages to standard error concerning the expansion of each file.