/usr/bin/chmod

Usage: /usr/bin/chmod [OPTION]... MODE[,MODE]... FILE...
  or:  /usr/bin/chmod [OPTION]... OCTAL-MODE FILE...
  or:  /usr/bin/chmod [OPTION]... --reference=RFILE FILE...
Change the mode of each FILE to MODE.
With --reference, change the mode of each FILE to that of RFILE.

  -c, --changes
         like verbose but report only when a change is made
  -f, --silent, --quiet
         suppress most error messages
  -v, --verbose
         output a diagnostic for every file processed
      --dereference
         affect the referent of each symbolic link,
         rather than the symbolic link itself
  -h, --no-dereference
         affect each symbolic link, rather than the referent
      --no-preserve-root
         do not treat '/' specially (the default)
      --preserve-root
         fail to operate recursively on '/'
      --reference=RFILE
         use RFILE's mode instead of specifying MODE values.
         RFILE is always dereferenced if a symbolic link.
  -R, --recursive
         change files and directories recursively

The following options modify how a hierarchy is traversed when the -R
option is also specified.  If more than one is specified, only the final
one takes effect. -H is the default.

  -H
         if a command line argument is a symlink to a directory, traverse it
  -L
         traverse every symbolic link to a directory encountered
  -P
         do not traverse any symbolic links

      --help
         display this help and exit
      --version
         output version information and exit

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

Report bugs to: <bug-coreutils@gnu.org>.
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
Full documentation <https://www.gnu.org/software/coreutils/chmod>
or available locally via: info '(coreutils) chmod invocation'