pmtraversepmns(3) [centos man page]

PMTRAVERSEPMNS(3)					     Library Functions Manual						 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(3C) 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.

Performance Co-Pilot							PCP							 PMTRAVERSEPMNS(3)

PMGETCHILDRENSTATUS(3)					     Library Functions Manual					    PMGETCHILDRENSTATUS(3)

NAME

       pmGetChildrenStatus - return the descendent nodes of a PMNS node and their respective status

C SYNOPSIS

       #include <pcp/pmapi.h>

       int pmGetChildrenStatus(const char *name, char ***offspring, int **status);

       cc ... -lpcp

DESCRIPTION

       Given a fully qualified pathname to a node in the current Performance Metrics Name Space (PMNS), as identified by name, pmGetChildrenStatus
       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.

       If status is not NULL, then pmGetChildrenStatus will also return the status of each child via status.  The status will refer  to  either  a
       leaf node (with value PMNS_LEAF_STATUS ) or a non-leaf node (with value PMNS_NONLEAF_STATUS ).

       Normally,  pmGetChildrenStatus  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
       pmGetChildrenStatus  with a single call to malloc(3C), and it is the responsibility of the pmGetChildrenStatus caller to free(offspring) to
       release the space when it is no longer required.  The same holds true for the status array.

       When an error occurs, or name is a leaf node (i.e. the result of pmGetChildrenStatus is less than one), both offspring and status are unde-
       fined (no space will have been allocated, and so calling free(3C) 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	configura-
       tion file, as described in pcp.conf(5).	Values for these variables may be obtained programmatically using the pmGetConfig(3) function.

SEE ALSO

       PMAPI(3),   pmGetChildren(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 pmGetChildrenStatus 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.

Performance Co-Pilot							PCP						    PMGETCHILDRENSTATUS(3)