pmdaclosehelp(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)

PMDACHILDREN(3) 					     Library Functions Manual						   PMDACHILDREN(3)

NAME

       pmdaChildren - translate a PMID to a set of dynamic performance metric names

C SYNOPSIS

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

       int pmdaChildren(char *name, int traverse, char ***offspring, int **status, pmdaExt *pmda);

       cc ... -lpcp_pmda -lpcp

DESCRIPTION

       As part of the Performance Metrics Domain Agent (PMDA) API (see PMDA(3)), pmdaChildren is the generic callback for returning dynamic metric
       names (and their status) that are descendants of name.

       Because implementing dynamic performance metrics requires specific PMDA support, and the facility is an optional component of a PMDA  (most
       PMDAs do not support dynamic performance metrics), pmdaChildren is a skeleton implementation that returns PM_ERR_NAME.

       A  PMDA	that  supports	dynamic  performance  metrics  will  provide  a private callback that replaces pmdaChildren (by assignment to ver-
       sion.four.children of the pmdaInterface structure) and takes the initial metric name and returns names via offspring[] and the leaf or non-
       leaf status of each via status[].

       If traverse is 0, then the behaviour is akin to pmGetChildren(3) and offspring[] contains the relative name component for the immediate de-
       scendants of name.

       If traverse is 1, then the behaviour is akin to pmTraversePMNS(3) and offspring[] contains the absolute names of all dynamic  metrics  that
       are decedents of name.

       The  resulting  list  of pointers offspring and the values (the names) that the pointers reference will have been allocated by pmdaChildren
       with a single call to malloc(3C), and the caller of pmdaChildren will call free(offspring) to release the space when it is  no  longer  re-
       quired.	The same holds true for the status array.

DIAGNOSTICS

       pmdaChildren  returns  PM_ERR_NAME  if  the name is not recognized or cannot be translated, otherwise the number of descendent metric names
       found.

CAVEAT

       The PMDA must be using PMDA_PROTOCOL_4 or later, as specified in the call to pmdaDSO(3) or pmdaDaemon(3).

SEE ALSO

       PMAPI(3), PMDA(3), pmdaDaemon(3), pmdaDSO(3), pmdaMain(3), pmGetChildren(3) and pmTraversePMNS(3).

Performance Co-Pilot							PCP							   PMDACHILDREN(3)