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).

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.

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).