All directories and files have flags called mode bits that decide whether they can be read, written to, or executed. Executing a file means running it like a program or … See more

You can see the permissions for files by using the lscommand and the (long format) option. … See more

The default permissions for a directory are 777, and the default permissions for a file are 666. That gives every user full access to all directories, and the ability to read and write any fil… See more

The umask value is set globally with one value for root and a different one for all other users. But it can be set to a new value for anyone. To see what the current umask setti… See more

Subtracting the mask value from the default permissions gives you the actual permissions. In other words, if a permission is set in the umask value it will not be set in the permiss… See more