7. Permission Bits

chmod() system call, chmod command

$ ls -ld . notes.html /bin/ls
drwxr-xr-x 2 perry perry   4096 Jun 17 14:20 .
-rwxr-xr-x 1 root  root  133792 Jan 18  2018 /bin/ls
-rw-r--r-- 1 perry perry   1118 Jun 17 14:18 notes.html
$

user, group, other; read, write, execute:

  -rwxr-xr-x
   uuugggooo
   111101101 = 0755

  -rw-r--r--
   uuugggooo
   110100100 = 0644