Use the "with" prepositional phrase to qualify an NCL command to limit the scope of its operation. Also called filtering, this process is useful in displaying or acting upon only certain information. The expression supplied as part of the with clause must be an attribute of the entity (or entities) specified in the command. ncl> show session control application *, with maximum instances>0 For every session control application entity on node 0 (the local system), NCL finds the entities with maximum instances greater than zero, and returns the identifying information about those session control application entities. The with prepositional phrase is a boolean expression that can use the relational operators as follows: Symbol Meaning <> Not equals < Less than <= Less than or equal to > Greater than >= Greater than or equal to
1 – Restrictions of With Clause
It is possible (but not improbable) for the value of an attribute to change between the time that the attribute value is tested against the with clause value and the time that the directive is actually issued to the entity. This limitation can lead to cases such as the following: ncl> show 0 session control port *, with send queue > 0 Node 0 Session Control Port %XCC354000 AT 1994-11-13-16:32:03.249-05:00I0.269 Status Send Queue = 0 In this case, the attribute briefly goes non-zero, then immediately returns to zero again. Unfortunately, the attribute changed value between the time that it was sampled by the entity filtering software in the CML (CMIP Management Listener) and the time that the Show directive was issued to that entity instance. This is generally not a problem. Most attributes are stable enough that this rarely happens.