pmdahelp(3) — Linux manual page

NAME | C SYNOPSIS | DESCRIPTION | DIAGNOSTICS | CAVEAT | SEE ALSO | COLOPHON

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 
       ⟨http://www.pcp.io/⟩.  If you have a bug report for this manual
       page, send it to pcp@groups.io.  This page was obtained from the
       project's upstream Git repository
       ⟨https://github.com/performancecopilot/pcp.git⟩ on 2020-12-18.
       (At that time, the date of the most recent commit that was found
       in the repository was 2020-12-18.)  If you discover any rendering
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       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

Performance Co-Pilot               PCP                       PMDAHELP(3)