NAME

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

C SYNOPSIS

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

       int pmdaOpenHelp(const 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.

CAVEAT

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

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.

SEE ALSO

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