which may be absolute or symbolic.
set group ID on execution
execute (search in directory) by owner
read, write, execute (search) by group
read, write, execute (search) by others
.RI [ "op permission" "] ..."
(for user's permissions),
is any combination of the letters
The first example denies write permission to others,
the second makes a file executable:
Multiple symbolic modes separated by commas may be given.
Only the owner of a file (or the super-user) may change its mode.