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pmtraversepmns(3)

NAME

   pmTraversePMNS,  pmTraversePMNS_r  -  traverse  the performance metrics
   name space

C SYNOPSIS

   #include <pcp/pmapi.h>

   int pmTraversePMNS(const char *name, void (*dometric)(const char *));
   int pmTraversePMNS_r(const char *name, void (*dometric_r)(const char *, void *), void *closure);

   cc ... -lpcp

DESCRIPTION

   The routine  pmTraversePMNS  may  be  used  to  perform  a  depth-first
   traversal of the Performance Metrics Name Space (PMNS).

   The  traversal  starts  at  the node identified by name - if name is an
   empty string (i.e. ""), the traversal starts at the root of  the  PMNS.
   Usually name would be the pathname of a non-leaf node in the PMNS.

   For  each  leaf  node (i.e. performance metric) found in the traversal,
   the user-supplied routine dometric is called with the full pathname  of
   that metric in the PMNS as the single argument.  This argument is null-
   byte terminated, and is constructed  from  a  buffer  that  is  managed
   internally  to  pmTraversePMNS.   Consequently  the value is only valid
   during the call to dometric - if the pathname needs to be retained,  it
   should be copied using strdup(3) before returning from dometric.

   The  pmTraversePMNS_r  routine  performs  the same function, except the
   callback method func_r has an additional parameter that will be closure
   from the initial call to pmTraversePMNS_r.  The additional parameter to
   pmTraversePMNS_r and the callback method  allows  the  caller  to  pass
   context  through  pmTraversePMNS_r and into the callback method func_r,
   making the service more useful for  multi-threaded  applications  where
   thread-private  data  can  be  accessed  in the callback method via the
   closure argument.

   On success pmTraversePMNS returns the number of children of name, which
   may be zero.

SEE ALSO

   PMAPI(3) and pmGetChildren(3).

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 pmTraversePMNS must
          be made inside a current context.

   PM_ERR_NAME
          The initial 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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