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Links

LINK link-type target name-component host-type host-name hsoname-type hsoname object-version [ DEST-EXP dest-expiration ]

In the case of links to objects, dest-expiration is the value of the object's DEST-EXP field.

The link-type token is defined as follows:

L
Normal link (Symbolic link, link to a Prospero object, or link to an external object)
U
Union link to a directory

The target token is defined as follows:  (Also see the discussion of this in section gif. A link may be a link to an object. In this case, the value of the target token will be the same as the value of the object's BASE-TYPE attributegif (that is, OBJECT, FILE, DIRECTORY, or DIRECTORY+FILE.) Other values for target are:

SYMBOLIC
Symbolic link. The host-type token will be VIRTUAL-SYSTEM, the host-name token will be the name of the virtual system being linked to (specified as a path within the current virtual system -- we usually use the conventional ugly-name of the virtual system), the hsoname-type will be ASCII, and the hsoname will be the full pathname of the object being linked to within the virtual system.

EXTERNAL
This is a link to an object which is not stored on a host running Prospero. Unlike other types of links, EXTERNAL links have an ACCESS-METHODgif attribute which is returned as a cached attribute. This is because EXTERNAL links cannot have any object attributes. Therefore, if one wishes to add attributes to an EXTERNAL link that would normally be object attributes, one must specify them as CACHED, ADDITIONAL, or REPLACEMENT attributes.

If the principal requesting the listing has no read access to a link, all fields in the link except for name-component will be returned with the token NULL, which is not otherwise valid in a returned link.


next up previous contents
Next: Link Attributes Up: Returned Information Previous: Returned Information

Padma Indraganti
Thu Jun 20 13:02:20 PDT 1996