User and Group IDs [ New Features of MPE/iX: Using the Hierarchical File System ] MPE/iX 5.0 Documentation
New Features of MPE/iX: Using the Hierarchical File System
User and Group IDs
Each MPE/iX user has an associated user ID (UID). The UID is a string (in
the form user.account) and a corresponding integer value. Additionally,
one or more users can be organized into groups (distinct from MPE groups)
to simplify file sharing. Each group has an associated group ID (GID).
The GID is a string (in the form account) with a corresponding integer
value.
UIDs and GIDs are used in conjunction with other security mechanisms to
control access to objects. Objects are entities that contain or receive
information, such as files, directories, and devices.
A process is a program that is currently being executed. Every process
has a UID, one or more GIDs, an optional file mode creation mask
(specifies which permissions should not be granted), and a set of
capabilities (for example, SM, AL, GL, ND, SF, etc.). MPE/iX Release 5.0
only supports one GID per process.
When files or directories are created, they are assigned their parent
directory's GID and the UID of the process creating them. File and
directory UIDs and GIDs can be changed using the chown() function
available through the MPE/iX shell.
MPE/iX 5.0 Documentation