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 Performance Metrics Name Space (PMNS), as identified by name, pmGetChildren 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 immediate 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 associated with a leaf node in the PMNS. The resulting list of pointers offspring and the values (the relative 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).
Environment variables with the prefix PCP_ are used to parameterize the file and directory names used by PCP. On each installation, the file /etc/pcp.conf contains the local values for these variables. The $PCP_CONF variable may be used to specify an alternative 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).
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.
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 email@example.com. This page was obtained from the project's upstream Git repository ⟨https://github.com/performancecopilot/pcp.git⟩ on 2021-04-01. (At that time, the date of the most recent commit that was found in the repository was 2021-04-01.) 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 firstname.lastname@example.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)