-f, --force
       change permissions to allow writing if necessary

-n, --iterations=N
       overwrite N times instead of the default (3)

--random-source=FILE
       get random bytes from FILE

-s, --size=N
       shred this many bytes (suffixes like K, M, G accepted)

-u, --remove
       truncate and remove file after overwriting

-v, --verbose
       show progress

-x, --exact
       do not round file sizes up to the next full block;

       this is the default for non-regular files

-z, --zero
       add a final overwrite with zeros to hide shredding

--help display this help and exit

--version
       output version information and exit