"-a, --all" Display counts for all files, not just directories.
"-b, --bytes" Print sizes in bytes.
"-c, --total" Write a grand total of all of the arguments after all arguments have been processed. This can be used to find out the disk usage of a directory, with some files excluded.
"-k, --kilobytes" Print sizes in kilobytes. This overrides the environment variable POSIXLY_CORRECT.
"-l, --count-links" Count the size of all files, even if they have appeared already in another hard link.
"-s, --summarize" Display only a total for each argument.
"-x, --one-file-system" Skip directories that are on different filesystems from the one that the argument being processed is on.
"-D, --dereference-args" Dereference symbolic links that are command line arguments. Does not affect other symbolic links. This is helpful for finding out the disk usage of directories like /usr/tmp where they are symbolic links.
"-L, --dereference" Dereference symbolic links (show the disk space used by the file or directory that the link points to instead of the space used by the link).
"-S, --separate-dirs" Count the size of each directory separately, not including the sizes of subdirectories.
"--help" Print a usage message on standard output and exit successfully.
"--version" Print version information on standard output then exit successfully.