NAME

       pmLoadDerivedConfig - load derived metric definitions from a file

C SYNOPSIS

       #include <pcp/pmapi.h>

       int pmLoadDerivedConfig(char *fname);

       cc ... -lpcp

DESCRIPTION

       Each  line  of the file fname is either a comment line (with a ``#'' in the first position
       of the line) or the declaration of a derived performance metric, specified as:

       * the name of the derived metric, using the same ``dot notation'' syntax that is used  for
         PCP performance metrics, see PCPIntro(1) and pmns(5).

       * an equals sign (``='')

       * a valid expression for a derived metric, as described in pmRegisterDerived(3).

       White space is ignored in the lines.

       For  each  line  containing a derived metric definition, pmRegisterDerived(3) is called to
       register the new derived metric.

       The result from pmLoadDerivedConfig will be the number  of  derived  metrics  loaded  from
       fname else a value less than zero in the case of an error.

EXAMPLE

       # sample derived metric definitions
       bad_in_pkts = network.interface.in.errors + network.interface.in.drops
       # note the following would need to be on a single line ...
       disk.dev.read_pct = 100 * delta(disk.dev.read) /
                   (delta(disk.dev.read) + delta(disk.dev.write))

SEE ALSO

       PCPIntro(1), PMAPI(3) and pmRegisterDerived(3).