Permissions Octal Values

• r (read): 4
• w (write): 2
• x (execute): 1

chmod 764 file would mean rwx for owner, rw for group, and r for others.

umask is the default set of permissions that subtracts from 666 for files, and 777 for directories

umask
0002

touch file

stat -c "%a" file
664

chmod can use octal mode/numeric (like above) or symbolic.

Here we change the file permissions for owner and group to rwx

chmod og+rwx file