The default securit y at account, group, and ￿le lev els are as follo ws: Account level

SYS (R,X:ANY;W,A,L:AC)

other accounts (R,X,W,A,L:AC)

Group level

PUB (R,X:ANY;A,W,L,S:AL,GU) other groups (R,W,A,L,X,S:GU)

File level

(R,X,W,A,L:ANY)

At the group level, the MPE/iX Securit y System recognizes six access modes:Reading (R) Appending (A) Writing (W) Locking (L) Executing (X) Saving (S)It recognizes sev en user types:Any User (ANY)Account Librarian User (AL)

Group Librarian User (GL) Group User (GU) Account Member (AC) System Manager (SM) Account Manager (AM)

For detailed information on this topic, refer to Accessing Files Pr ogrammer's Guide (32650-90017).

When a ￿le is created, the securit y provisions that apply to it are the default pro visions assigned by MPE/iX at the ￿le lev el, coupled with the user-speci￿ed or default pro visions assigned to the accoun t and group to whic h the ￿le belongs. At any time, however, the creator of the ￿le can change the ￿le level security provisions. Thus, the total securit y provisions for a ￿le depend on speci￿cations made at three lev els: account, group, and ￿le. A user m ust pass tests at the accoun t, group, and ￿le lev els (in order) to successfully access a ￿le in the requested mode.

If no security provisions are explicitly speci￿ed b y the user, the follo wing provisions are assigned at the ￿le lev el by default:

Reading (R) Appending (A) Writing (W) Locking (L) Executing (X) Any User (ANY)

Because the total securit y for a ￿le always depends on securit y at all three lev els, a ￿le not explicitly protected from a certain access mode at the ￿le lev el may bene￿t from the default

File System 6-41