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).
