Execute (X) Access [ 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
Execute (X) Access
The hierarchical file system does not provide a way to distinguish files
containing executable scripts from other files. However, the POSIX
standard requires that file permission bits should be checked to verify
that execute access has been granted to at least one of the file classes
as an indication that a file contains executable statements.
On MPE/iX, when all access would normally be granted to a user, X access
is handled as a special case. Users with appropriate privilege are
granted X access only if the file has an executable file code (PROG, SL,
NMPRG, or NMXL), if the file access matrix assigns X access to at least
one user class, or if the file has an ACD that assigns X access to at
least one user.
The file owner is granted X access only if the $OWNER ACD entry grants X
access. If the $OWNER entry does not exist, the file owner is granted X
access if the file has an executable file code or at least one user is
granted X access by the file access matrix or an ACD.
A RELEASEd file grants X access to all users.
These rules do not affect other uses of X access on the system, and they
are backwards compatible with the use of X access on releases before
Release 4.5. Users with appropriate privilege still get X access to
files with executable file codes. X is also used to grant STREAM access
to JOB files. Users with appropriate privilege can still stream these
files because they have R access to the files.
MPE/iX 5.0 Documentation