In configuration files and (to a lesser extent) command line
options, metric specifications adhere to the following syntax
rules by most tools. See the tool specific manual pages for the
exact syntax supported.
If the source of performance metrics is real-time from pmcd(1)
then the accepted syntax is
host:metric[instance1,instance2,...]
If the source of performance metrics is a set of PCP archive logs
then the accepted syntax is
archive/metric[instance1,instance2,...]
The host:, archive/ and [instance1,instance2,...] components are
all optional.
The , delimiter in the list of instance names may be replaced by
white space.
Special characters in instance names may be escaped by
surrounding the name in double quotes or preceding the character
with a backslash.
White space is ignored everywhere except within a quoted instance
name.
An empty instance is silently ignored, and in particular ``[]''
is the same as no instance, while ``[one,,,two]'' is parsed as
specifying just the two instances ``one'' and ``two''.
As a special case, if the host is the single character ``@'' then
this refers to a PM_CONTEXT_LOCAL source, see pmNewContext(3).
