Help! I know umask subtracts default permissions from new files that will be created, but how do you reverse that? How can I ADD default permissions to new files that will be created?

Umask creates a filter of permissions for all new files created within a certain partition - So to add "default" permissions for all new files within a certain partition add a umask value to the options section of /etc/fstab regards the relevant partition.

(In the process of "subtracting" default permissions umask leaves some behind - the permissions left behind become the default permissions)

( Chmod is the "inverse" of Umask - Chmod can be used to change the permissions on an individual file - however - for your scenario - you need Umask - Umask is used to create default permissions for all new files. )

Skyline, thanks for the help, but I guess I asked the question wrong. How do I undo an umask setting once I've set it? I set umask to a permission level I didn't mean to, and I'd like to go back to the default before I set umask.

How and where did you set the umask setting and what does it apply to?

In /root I issued the command: umask 777, and now when I touch new files in the root's home they all have ---------- permissions.

umask=777

will give no permissions to anyone

whereas

umask=022

will give the "owner" Read Write Execute
group - Read and execute
other - Read and execute

This is a more suitable default umask setting

AFIK to make a general change to the default umask setting for all new files and directories youd need to change the setting in /etc/profile or .cshrc or your .login file.