NAME
pmdaConnect - establish a connection between a daemon PMDA and PMCD
C SYNOPSIS
#include <pcp/pmapi.h>
#include <pcp/impl.h>
#include <pcp/pmda.h>
void pmdaConnect(pmdaInterface * dispatch);
cc ... -lpcp_pmda -lpcp
DESCRIPTION
pmdaConnect initializes an IPC channel between a PMDA(3) and the
pmcd(1) process on the local host. The type of the connection is
dependent on the e_io field of the pmdaExt structure:
pmdaPipe Use stdin/stdout to communicate; assumes this is a pipe
created by pmcd before the PMDA(3) was launched.
pmdaInet Assume pmcd(1) will establish a connection to an
internet domain socket set up by the PMDA(3). The name
or number of the port must be specified in the
e_sockname or e_port fields of the pmdaExt structure,
respectively.
pmdaUnix Assume pmcd(1) will establish a connection to a unix
domain socket set up by the PMDA(3). The port number
must be specified in the e_port field of the pmdaExt
structure.
pmdaUnknown The initial value of e_io which defaults to using
stdin/stdout.
The relevant pmdaExt fields are initialized by pmdaInit(3) and set by
pmdaGetOpt(3), so most PMDAs should not need to access or modify them.
DIAGNOSTICS
pmdaConnect will log the type of connection made to pmcd(1) if the
PMAPI(3) debug control variable (pmDebug) has the DBG_TRACE_LIBPMDA
flag set.
If an error occurs that is unrecoverable, dispatch->status is set to a
value less than 0, otherwise it is zero or positive.
CAVEAT
The PMDA must be using PMDA_INTERFACE_2 or later, as specified in the
call to pmdaDaemon(3).
SEE ALSO
pmcd(1), pipe(2), socket(2), PMAPI(3), PMDA(3), pmdaDaemon(3),
pmdaGetOpt(3) and pmdaInit(3).