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NAME | C SYNOPSIS | DESCRIPTION | EXAMPLE | DIAGNOSTICS | SEE ALSO | COLOPHON |
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PMLOOKUPNAME(3) Library Functions Manual PMLOOKUPNAME(3)
pmLookupName - translate performance metric names into PMIDs
#include <pcp/pmapi.h>
int pmLookupName(int numpmid, const char **namelist, pmID *pmidlist);
cc ... -lpcp
Given a list in namelist containing numpmid full pathnames for
performance metrics from a Performance Metrics Name Space (PMNS),
pmLookupName returns the list of associated Performance Metric
Identifiers (PMIDs) via pmidlist.
The result from pmLookupName depends on the presence of any
lookup failures, their severity and the number of metrics being
looked up.
1. If there are no lookup failures, the return value will be
numpmid.
2. If a fatal error is encountered, the return value will be
less than 0. For example PM_ERR_TOOSMALL, PM_ERR_NOPMNS or
PM_ERR_IPC.
3. If numpmid is greater than one and non-fatal error(s) are
encountered, the return value is the number of metric names
that have successfully been looked up (greater than or equal
to zero and less than or equal to numpmid).
4. If numpmid is one and a non-fatal error is encountered, the
return value is the error code (less than zero).
When errors are encountered, any metrics that cannot be looked up
result in the corresponding element of pmidlist being set to
PM_ID_NULL.
The slightly convoluted error protocol allows bulk lookups, then
probing for more error details in the case of a specific failure,
as shown in the EXAMPLES section below.
Note that the error protocol guarantees there is a 1:1
relationship between the elements of namelist and pmidlist, hence
both lists contain exactly numpmid elements. For this reason,
the caller is expected to have preallocated a suitably sized
array for pmidlist.
#include <pcp/pmapi.h>
#define NUMPMID (sizeof(names)/sizeof(const char *))
const char *names[] = {
"sample.bin",
"sample",
"sample.bog",
"sample.secret.bar",
"sample.secret.bar.bad"
};
pmID pmids[NUMPMID];
int
main(int argc, char **argv)
{
int sts;
int numpmid = NUMPMID;
pmNewContext(PM_CONTEXT_HOST, "local:");
sts = pmLookupName(numpmid, names, pmids);
if (sts < 0) {
fprintf(stderr, "pmLookupName failed: %s0, pmErrStr(sts));
exit(1);
}
if (sts != numpmid) {
/*
* some of the lookups failed ... report the reason(s)
*/
int i;
for (i = 0; i < numpmid; i++) {
if (pmids[i] != PM_ID_NULL) continue;
/* this one failed */
sts = pmLookupName(1, &names[i], &pmids[i]);
fprintf(stderr, "%s: lookup failed: %s0, names[i], pmErrStr(sts));
}
exit(1);
}
/* all good ... */
...
}
PM_ERR_TOOSMALL
numpmid must be at least 1
PM_ERR_NOPMNS
Failed to access a PMNS for operation. Note that if the
application hasn't a priori called pmLoadNameSpace(3) and
wants to use the distributed PMNS, then a call to
pmLookupName must be made after the creation of a context
(see pmNewContext(3)).
PM_ERR_NAME
namelist[0] does not correspond to a valid metric name in
the PMNS.
PM_ERR_NONLEAF
namelist[0] refers to a node in the PMNS but it was not a
leaf node.
PM_ERR_*
Other diagnostics are for protocol failures when accessing
the distributed PMNS.
PMAPI(3), pmGetChildren(3), pmGetChildrenStatus(3),
pmGetConfig(3), pmLoadNameSpace(3), pmNameID(3), pmNewContext(3),
pcp.conf(5) and pcp.env(5).
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 2024-06-14.
(At that time, the date of the most recent commit that was found
in the repository was 2024-06-14.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
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 PMLOOKUPNAME(3)
Pages that refer to this page: pmgenmap(1), pmprobe(1), pmseries(1), pcpintro(3), pmapi(3), pmdapmid(3), pmfetch(3), pmfetchgroup(3), pmgetchildren(3), pmgetchildrenstatus(3), pmgetderivedcontrol(3), pmlookuplabels(3), pmnameall(3), pmnameid(3), pmparsemetricspec(3), pmregisterderived(3), pmwebapi(3), QmcContext(3), LOGARCHIVE(5)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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