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pmgetchildren(3)

NAME

   pmGetChildren - return the descendent nodes of a PMNS node

C SYNOPSIS

   #include <pcp/pmapi.h>

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

   cc ... -lpcp

DESCRIPTION

   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).

PCP ENVIRONMENT

   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.

SEE ALSO

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

DIAGNOSTICS

   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.



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