Core Services

• 
  This service returns a value representing the active node upon which the PLAN program is currently executing. Note that is an abstract type. In the event that the active node cannot resolve its own name, an exception will be raised.

• 
  Takes as input a name, according to the following grammar:

  

  where ip-addr has the form where each n is an integer from 0 to 255. If the port-num argument is not provided, then it is assumed to be the same port as the invoking node. getHostByName attempts to resolve this name into a value of the PLAN type. Raises an exception on failure.

• 
  Returns the amount of global resource bound that the current packet has available.

• 
  Returns a random integer.

• 
  Returns a pair (2-tuple) consisting of the number of seconds and milliseconds since January 1, 1970, 00:00:00 GMT.

• 
  Converts the argument (a PLAN value) into a string.

• 
  Converts the argument (a PLAN value) into a string. If this call occurs on the node on which this PLAN application originated, then the output will be made available to the initiating process (e.g., PLANStart). The underlying mechanism for print is the PLAN port created by the injecting host program between it and the originating node. Ports are discussed in more detail in Subsection 6.2.2.

• 
  This is a default routing function available to PLAN programs; executed on a node n, returns a host such that is the ``next hop'' on the way to h from n. In the current release, this function makes use of SLRP [5] to generate its routing tables (see getRouteTable, below).

• 
  Returns a list of hosts which are directly reachable from the invoking host (not including the invoking host itself). In other words, it is these hosts which may be used by the OnNeighbor primitive while on the invoking hosts (all others will cause an exception to be raised).

• 
  Returns a list of pairs of hosts such that the first host of each pair indicates a potential destination in the network, and the second host indicates the ``next hop'' on a route to that host. Note that the set of all of the first elements of the pairs indicate all reachable destinations in the network, while the set of all second elements form a subset of the list of nodes returned by getNeighbors. In routing protocols that support default routing, the default route is indicated by the pair whose first element is the host ``Unknown.''