trusty (3) __pmSpecLocalPMDA.3.gz

NAME

       __pmSpecLocalPMDA - process command-line argument for the table of DSO PMDAs

C SYNOPSIS

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

       char *__pmSpecLocalPMDA(const char *spec);

       cc ... -lpcp

DESCRIPTION

       PCP contexts of type PM_CONTEXT_LOCAL are used by clients that wish to fetch metrics directly from one or
       more PMDAs on the local host without involving pmcd(1).

       __pmSpecLocalPMDA provides a convenience wrapper to be used by applications that wish to  use  a  command
       line  argument  (usually  with  -K)  to  control  the DSO PMDAs that are available for a PM_CONTEXT_LOCAL
       context.

       The spec argument specifies actions for one or more DSO PMDAs using up to four fields separated by commas
       (``,''), namely:
       -  an opcode with one of the values add (add a new entry), del (delete an existing entry) or clear (clear
          all entries from the table).
       -  the PMDA's domain number
       -  the path to the PMDA DSO (may be absolute or relative to the $PCP_VAR_DIR/pmdas directory and the  DSO
          suffix is optional), and
       -  the name of the PMDA's initialization routine.

       All  fields  are  required  to add a new entry.  To delete an entry the opcode is required plus either or
       both of the domain number and path fields.  To clear all entries, only the opcode is required.

       If spec is parsed successfully, then __pmLocalPMDA(3) is called with the extracted arguments.

RETURN VALUE

       On success, __pmSpecLocalPMDA will return NULL.

       On error or failure, __pmSpecLocalPMDA will return a pointer to a static error message.

EXAMPLES

       Some examples of valid spec strings:

       clear  Delete all entries from the DSO table.

       add,123,foo/foo_pmda,foo_init
              Add the ``foo'' PMDA using domain 123.  The PMDA's DSO is  most  likely  in  below  the  directory
              $PCP_PMDAS_DIR and named foo/foo_pmda.so (for ELF-style platforms) or foo/foo_pmda.dylib (for BSD-
              style platforms) or fooo_pmda.dll (for Windows-style platforms).  The initialization  routine  for
              the ``foo'' PMDA is foo_init().

       del,123
              Delete the entry for the DSO with domain 123.

       del,,foo/foo_pmda
              Delete the entry with a pathname to the DSO that matches foo/foo_pmda.

       del,123,foo/foo_pmda
              Delete  the  entry  for  the  DSO with either domain 123 and/or a pathname to the DSO that matches
              foo/foo_pmda.

SEE ALSO

       PMAPI(3), __pmLocalPMDA(3) and pmNewContext(3).