PMDAINSTANCE(3)

NAME
pmdaInstance - return instance descriptions for a PMDA

C SYNOPSIS
#include <pcp/pmapi.h>
#include <pcp/impl.h>
#include <pcp/pmda.h>

int pmdaInstance(pmInDom indom, int inst, char *name, __pmInResult **result, pmdaExt *pmda);

cc ... -lpcp_pmda -lpcp

DESCRIPTION
pmdaInstance uses the standard PMDA(3) data structures to return information concerning the instance domain indom.

The result structure is constructed by pmdaInstance and will contain one or more instance names and/or identifiers as specified by the inst and name arguments.

If inst has the value PM_IN_NULL and name is a null string, result will contain all the instances names and identifiers in the instance domain.

If inst is PM_IN_NULL but name is the name of an instance in the instance domain indom, then result will contain the instance identifier for instance name. Note that if name contains no spaces, partial matching up to the first space in the instance name is performed, i.e. ``1'' will match instance name ``1 minute''. If name contains an embedded space, then no partial matching is performed and name should match one of the instance names exactly.

If name is a null string but inst is an instance identifier in the instance domain indom, then result will contain the name for instance inst. The result structure is allocated with malloc(3) and should be released by the caller with free(3).

DIAGNOSTICS
If any errors occur during the execution of pmdaInstance, the result structure is deallocated. If the instance domain indom is not supported by the PMDA, pmdaInstance will return PM_ERR_INDOM.

If the inst or name does not correspond to any instances in the indom domain, pmdaInstance will return PM_ERR_INST.

CAVEAT
The PMDA must be using PMDA_INTERFACE_2 or later, as specified in the call to pmdaDSO(3) or pmdaDaemon(3).

Because of optional partial matching up to the first space in the instance name, the PMDA developer should ensure that if instance names are allowed to have spaces, the names are unique up to the first space.

SEE ALSO
malloc(3), PMAPI(3), PMDA(3) and pmGetInDom(3).