pmdaGetInDomHelp(3) — Linux manual page


PMDAHELP(3)               Library Functions Manual               PMDAHELP(3)

NAME         top

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

C SYNOPSIS         top

       #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         top

       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         top

       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         top

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

SEE ALSO         top

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

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at ⟨⟩.
       If you have a bug report for this manual page, send it to  This page was obtained from the project's upstream
       Git repository ⟨⟩ on
       2020-09-18.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-09-18.)  If you discover any
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       (which is not part of the original manual page), send a mail to

Performance Co-Pilot                 PCP                         PMDAHELP(3)