In the Framework, RPN expressions are the superset of those
in RRDtool. See the
rrdtool graph manual at
%, the modulo operator. In RRFW parameter value, percent sign is reserved for parameter substitution.
In certain context, the values of the datasources can be evaluated into RPN expression.
The general format for data access is following:
FUNC@ specifies a special function to be performed on the
data being accessed.
For monitor expressions,
T@ returns the timestamp of the data source.
rrd-cdef leaf types and for
rrd-multigraph datasource types,
the following functions affect the graph shape:
LAST@. They cause the corresponding Consolidation Function
being used when creating a graph.
PATH specifies the relative name for the data source.
If omitted, the current leaf value is taken. If starts with
the path is considered as absolute.
Path starting with letter denotes the child of the parent subtree.
Double dot (
../) in the beginning of the path is interpreted as
current parent's parent subtree.
(OFFSET) determines the time reference, as described in
manual. In addition, the word
LAST refers to the latest data timestamp
(OFFSET) is currently supported in Monitor expressions only.
Copyright (c) 2002-2004 Stanislav Sinyagin <email@example.com>