pmdahelp(3) [centos man page]

PMDAHELP(3)						     Library Functions Manual						       PMDAHELP(3)

NAME

       pmdaOpenHelp, pmdaGetHelp, pmdaGetInDomHelp, pmdaCloseHelp - help text support for a PMDA

C SYNOPSIS

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

       int pmdaOpenHelp(char *fname);
       char *pmdaGetHelp(int handle, pmID pmid, int type);
       char *pmdaGetInDomHelp(int handle, pmInDom indom, int type);
       void pmdaCloseHelp(int handle);

       cc ... -lpcp_pmda -lpcp

DESCRIPTION

       As  part  of the Performance Metrics Domain Agent (PMDA) API (see PMDA(3)), this group of routines is used to implement the processing of a
       PMDA's metric help information.

       These routines are really intended for internal use, and should not need to be called directly from any PMDA code.

       Briefly, the base name of the help text file (as created by newhelp(1)) is passed in via a -h command line option for a daemon PMDA  or	as
       an  argument  to pmdaDaemon(3) or pmdaDSO(3).  Then pmdaOpenHelp is called from pmdaInit(3) and returns a handle that is used in subsequent
       calls to identify a particular help text collection (each PMDA typically has only one such collection).

       Requests for help text are passed to pmdaText(3) which calls pmdaGetHelp or pmdaGetInDomHelp as required.

       Other than error cases in pmdaOpenHelp, pmdaCloseHelp is not called.

DIAGNOSTICS

       pmdaOpenHelp returns a negative value for failure, suitable for decoding with pmErrStr(3).  pmdaGetHelp and pmdaGetInDomHelp return NULL if
       the corresponding help text does not exist.

CAVEAT

       The PMDA must be using PMDA_PROTOCOL_2 or later, as specified in the call to pmdaDSO(3) or pmdaDaemon(3).

SEE ALSO

       newhelp(1), PMAPI(3), PMDA(3), pmdaDaemon(3), pmdaDSO(3), pmdaInit(3), pmdaText(3) and pmErrStr(3).

Performance Co-Pilot							PCP							       PMDAHELP(3)

PMDACONNECT(3)						     Library Functions Manual						    PMDACONNECT(3)

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 depen-
       dent 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 IPv4 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.

       pmdaIPv6       Assume  pmcd(1)  will establish a connection to an IPv6 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).

Performance Co-Pilot							PCP							    PMDACONNECT(3)