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NAME | C SYNOPSIS | DESCRIPTION | DIAGNOSTICS | PCP ENVIRONMENT | SEE ALSO | COLOPHON |
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PMGETCHILDREN(3) Library Functions Manual PMGETCHILDREN(3)
pmGetChildren - return the descendent nodes of a PMNS node
#include <pcp/pmapi.h>
int pmGetChildren(const char *name, char ***offspring);
cc ... -lpcp
Given a fully qualified pathname to a node in the current Perfor‐
mance Metrics Name Space (PMNS), as identified by name, pmGetChil‐
dren returns via offspring a list of the relative names of all of
the immediate descendent nodes of name in the current PMNS.
As a special case, if name is an empty string (i.e.""), the imme‐
diate descendants of the root node in the PMNS will be returned.
Normally, pmGetChildren will return the number of descendent names
discovered, else a value less than zero for an error. The value
zero indicates that name is a valid metric name, i.e. is associat‐
ed with a leaf node in the PMNS.
The resulting list of pointers offspring and the values (the rela‐
tive names) that the pointers reference will have been allocated
by pmGetChildren with a single call to malloc(3), and it is the
responsibility of the pmGetChildren caller to free(offspring) to
release the space when it is no longer required.
When an error occurs, or name is a leaf node (i.e. the result of
pmGetChildren is less than one), offspring is undefined (no space
will have been allocated, and so calling free(3) is a singularly
bad idea).
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
pmGetChildren must be made inside a current context.
PM_ERR_NAME
The pathname name is not valid in the current PMNS
PM_ERR_*
Other diagnostics are for protocol failures when accessing
the distributed PMNS.
Environment variables with the prefix PCP_ are used to parameter‐
ize the file and directory names used by PCP. On each installa‐
tion, the file /etc/pcp.conf contains the local values for these
variables. The $PCP_CONF variable may be used to specify an al‐
ternative configuration file, as described in pcp.conf(5). Values
for these variables may be obtained programmatically using the
pmGetConfig(3) function.
PMAPI(3), pmGetChildrenStatus(3), pmGetConfig(3),
pmLoadASCIINameSpace(3), pmLoadNameSpace(3), pmLookupName(3),
pmNameID(3), pcp.conf(5), pcp.env(5) and PMNS(5).
This page is part of the PCP (Performance Co-Pilot) project. In‐
formation 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
2025-08-11. (At that time, the date of the most recent commit
that was found in the repository was 2025-08-11.) 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 PMGETCHILDREN(3)
Pages that refer to this page: pmapi(3), pmdachildren(3), pmgetchildrenstatus(3), pmgetderivedcontrol(3), pmlookupname(3), pmnameall(3), pmnameid(3), pmtraversepmns(3), pmwebapi(3)
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HTML rendering created 2025-09-06 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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