pmGetChildren(3) — Linux manual page


PMGETCHILDREN(3)          Library Functions Manual          PMGETCHILDREN(3)

NAME         top

       pmGetChildren - return the descendent nodes of a PMNS node

C SYNOPSIS         top

       #include <pcp/pmapi.h>

       int pmGetChildren(const char *name, char ***offspring);

       cc ... -lpcp

DESCRIPTION         top

       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


       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)

SEE ALSO         top

       PMAPI(3), pmGetChildrenStatus(3), pmGetConfig(3),
       pmLoadASCIINameSpace(3), pmLoadNameSpace(3), pmLookupName(3),
       pmNameID(3), pcp.conf(5), pcp.env(5) and PMNS(5).

DIAGNOSTICS         top

              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.

              The pathname name is not valid in the current PMNS

              Other diagnostics are for protocol failures when accessing the
              distributed PMNS.

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at ⟨⟩.
       If you have a bug report for this manual page, send it to  This page was obtained from the project's upstream
       Git repository ⟨⟩ on
       2020-08-13.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-08-11.)  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

Performance Co-Pilot                 PCP                    PMGETCHILDREN(3)

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