pmdatext(3) [centos man page]

PMDATEXT(3)						     Library Functions Manual						       PMDATEXT(3)

NAME

       pmdaText - extract metric help text for a PMDA

C SYNOPSIS

       #include <pcp/pmapi.h>
       #include <pcp/impl.h>
       #include <pcp/pmda.h>

       int pmdaText(int ident, int type, char **buffer, pmdaExt *pmda);

       cc ... -lpcp_pmda -lpcp

DESCRIPTION

       As  part of the Performance Metrics Domain Agent (PMDA) API (see PMDA(3)), pmdaText uses the standard PMDA(3) data structures to return the
       help text for metric ident in buffer.  The help text must be located in help text files created with newhelp(1), and the  associated  files
       are automatically opened by pmdaInit(3).

       The  path  to the (basename of the) help text files can be set in the calls to pmdaDSO(3) or pmdaDaemon(3) and overridden by the -h command
       line option in pmdaGetOpt(3).

       The encoding of ident follows the internal scheme used below the routines pmLookupText(3) and pmLookupInDomText(3),  namely  ident  encodes
       either a metric identifier or an instance domain identifier, according to the value of type.

       The  type  argument  is	a  bit	mask  that  encodes  the  interpretation  of ident and the requested form of help text, as follows: either
       PM_TEXT_PMID if ident is a metric identifier, or PM_TEXT_INDOM if ident is an instance domain identifier, plus either  PM_TEXT_ONELINE  for
       the one line help text or PM_TEXT_HELP for the full help text.

       The buffer is managed internally (usually it is cached), and it should not be released or freed by the caller of pmdaText.

DIAGNOSTICS

       If the requested help text could not be obtained, pmdaText will return PM_ERR_TEXT.

CAVEAT

       The PMDA must be using PMDA_PROTOCOL_2 or later, as specified in the call to pmdaDSO(3) or pmdaDaemon(3).

SEE ALSO

       newhelp(1), malloc(3), PMAPI(3), PMDA(3), pmdaDaemon(3), pmdaDSO(3), pmdaInit(3), pmLookupInDomText(3) and pmLookupText(3).

Performance Co-Pilot							PCP							       PMDATEXT(3)

PMDAATTRIBUTE(3)					     Library Functions Manual						  PMDAATTRIBUTE(3)

NAME

       pmdaAttribute - informs a PMDA about client connection attributes

C SYNOPSIS

       #include <pcp/pmapi.h>
       #include <pcp/impl.h>
       #include <pcp/pmda.h>

       int pmdaAttribute(int context, int key, char *value, int length, pmdaExt *pmda);

       cc ... -lpcp_pmda -lpcp

DESCRIPTION

       As  part  of  the Performance Metrics Domain Agent (PMDA) API (see PMDA(3)), pmdaAttribute is the generic callback for responding to client
       connection attributes.  These attributes include client credential information, such as user ID and group ID.

       A PMDA that supports connection attributes will provide a private pmdaAttribute callback by  assignment	to  version.six.attribute  of  the
       pmdaInterface structure, and implement custom logic for any of the attribute key-value pairs of interest to it.

       All  attributes are associated with a specific client context, and these can be uniquely identified using the ctx first argument.  The PMDA
       should track client connections, and disconnections using the pmdaSetEndContextCallBack(3) interface, as a result.   The  pmdaGetContext(3)
       interface may be particularly helpful also.

       All  attributes	are  passed  as key-value pairs and the value is always passed as a null-terminated string of given length.  This includes
       numeric attributes like the user ID.

       The most commonly used attributes would be PCP_ATTR_USERID and  PCP_ATTR_GROUPID  but  others  may  also  be  optionally  passed  (such	as
       PCP_ATTR_USERNAME)  if  they  are  available.   Some  attributes  will  be  consumed  by  pmcd  and  never through passed to PMDAs, such as
       PCP_ATTR_PASSWORD.  A complete list of all possible attributes can be found in the headers listed above, all are prefixed by PCP_ATTR.

DIAGNOSTICS

       pmdaAttribute should return either zero on success, or a negative return code to indicate an error in handling the attribute.  This  return
       code  cannot  be  used  to indicate a client should be disallowed access - such functionality must be performed by the agent in response to
       callbacks for the client in question (using PM_ERR_PERMISSION for those specific callbacks, for that  specific  client.	 In  other  words,
       errors  will  be  be passed to PMCD but there is no guarantee made that the error will be return to the client and result in termination of
       the client, for example.

CAVEAT

       The PMDA must be using PMDA_PROTOCOL_6 or later, as specified in the call to pmdaDSO(3) or pmdaDaemon(3).

SEE ALSO

       PMAPI(3), PMDA(3), pmdaDaemon(3), pmdaDSO(3), pmdaMain(3) and pmdaGetContext(3).

Performance Co-Pilot							PCP							  PMDAATTRIBUTE(3)