/usr/bin/chmod

Change the mode of each FILE to MODE.
With --reference, change the mode of each FILE to that of RFILE.

Usage: chmod [OPTION]... MODE[,MODE]... FILE...
       chmod [OPTION]... OCTAL-MODE FILE...
       chmod [OPTION]... --reference=RFILE FILE...

Arguments:
  [MODE]
  [FILE]...

Options:
      --help               Print help information.
  -c, --changes            like verbose but report only when a change is made
  -f, --quiet              suppress most error messages [alias: --silent]
  -v, --verbose            output a diagnostic for every file processed
      --no-preserve-root   do not treat '/' specially (the default)
      --preserve-root      fail to operate recursively on '/'
  -R, --recursive          change files and directories recursively
      --reference <RFILE>  use RFILE's mode instead of MODE values
  -H                       if a command line argument is a symbolic link to a directory, traverse it
  -L                       traverse every symbolic link to a directory encountered
  -P                       do not traverse any symbolic links (default)
      --dereference        affect the referent of each symbolic link (this is the default), rather
                           than the symbolic link itself
  -h, --no-dereference     affect symbolic links instead of any referenced file (useful only on
                           systems that can change the ownership of a symlink)
  -V, --version            Print version

Each MODE is of the form [ugoa]*([-+=]([rwxXst]*|[ugo]))+|[-+=]?[0-7]+.