Guardian Procedure Calls Reference Manual

For a given access mode, the accessor's security level is checked against the file security level.
File access is allowed or not allowed as shown in Table 20. In this table, file security levels
are indicated by FUP security codes. For a given accessor security level, a Y indicates that
access is allowed to a file with the security level shown; a hyphen indicates that access is not
allowed.
Table 20 Allowed File Accesses
File Security LevelAccessor's Security Level
O G AU C
N
–
Y Y YY Y YYSuper ID user, local access
– – –Y Y Y–Super ID user, remote access
– – –Y Y Y–Owner or owner's group manager, remote access
– – –– Y Y–Member of owner's group, remote access
– – –– – Y–Any other user, remote access
Y Y YY Y Y–Owner or owner's group manager, local access
– Y Y– Y Y–Member of owner's group, local access
– – Y– –Y–Any other user, local access
If the caller to FILE_OPEN_ fails the security check, the open fails with an error 48. A file's
security can be obtained by a call to FILE_GETINFOLIST[BYNAME]_, FILEINFO, or by the File
Utility Program (FUP) INFO command.
If you are using the Safeguard product, this security information might not apply.
• Tape file open—access mode
The file system does not enforce read-only or write-only access for unlabeled tape, even though
no error is returned if you specify one of these access modes when opening a tape file.
• File open—exclusion and access mode checking
When a file open is attempted, the requested access and exclusion modes are compared with
those of any opens already granted for the file. If the attempted open is in conflict with other
opens, the open fails with error 12. Figure 7 lists the possible current modes and requested
modes, indicating whether an open succeeds or fails.
For the Optical Storage Facility only, the "process exclusive" exclusion mode is also supported.
Process exclusive is the same as exclusive for opens by other processes, but the same as shared
for opens by the same process.
NOTE: Protected exclusion mode has meaning only for disk files. For other files, specifying
protected exclusion mode is equivalent to specifying shared exclusion mode.
FILE_OPEN_ Procedure 465