


 RRRRRRRRDDDDpppp((((3333))))                           1111....0000....44445555                            RRRRRRRRDDDDpppp((((3333))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000003333----00007777----22221111



 NNNNAAAAMMMMEEEE
      RRDp - Attach rrdtool from within a perl script via a set of pipes;

 SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
      use RRRRRRRRDDDDpppp

      RRRRRRRRDDDDpppp::::::::ssssttttaaaarrrrtttt _p_a_t_h _t_o _r_r_d_t_o_o_l _e_x_e_c_u_t_a_b_l_e

      RRRRRRRRDDDDpppp::::::::ccccmmmmdddd  _r_r_d_t_o_o_l _c_o_m_m_a_n_d_l_i_n_e

      $answer = RRRRRRRRDDDD::::::::rrrreeeeaaaadddd

      $status = RRRRRRRRDDDD::::::::eeeennnndddd

      $$$$RRRRRRRRDDDDpppp::::::::uuuusssseeeerrrr,  $$$$RRRRRRRRDDDDpppp::::::::ssssyyyyssss, $$$$RRRRRRRRDDDDpppp::::::::rrrreeeeaaaallll

 DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
      With this module you can safely communicate with the rrdtool.

      After every RRRRRRRRDDDDpppp::::::::ccccmmmmdddd you have to issue an RRRRRRRRDDDDpppp::::::::rrrreeeeaaaadddd command to get
      rrrrrrrrddddttttoooooooolllls answer to your command. The answer is returned as a pointer,
      in order to speed things up. If the last command did not return any
      data, RRRRRRRRDDDDpppp::::::::rrrreeeeaaaadddd will return an undefined variable.

      If you import the PERFORMANCE variables into your namespace, you can
      access rrdtools internal performance measurements.

      use RRRRRRRRDDDDpppp
              Load the RRDp::pipe module.

      RRRRRRRRDDDDpppp::::::::ssssttttaaaarrrrtttt _p_a_t_h _t_o _r_r_d_t_o_o_l _e_x_e_c_u_t_a_b_l_e
              start rrdtool. The argument must be the path to the rrdtool
              executable

      RRRRRRRRDDDDpppp::::::::ccccmmmmdddd _r_r_d_t_o_o_l _c_o_m_m_a_n_d_l_i_n_e
              pass commands on to rrdtool. check the rrdtool documentation
              for more info on the rrdtool commands.

      $answer = RRRRRRRRDDDDpppp::::::::rrrreeeeaaaadddd
              read rrdtools response to your command. Note that the $answer
              variable will only contain a pointer to the returned data. The
              reason for this is, that rrdtool can potentially return quite
              excessive amounts of data and we don't want to copy this
              around in memory. So when you want to access the contents of
              $answer you have to use $$answer which dereferences the
              variable.

      $status = RRRRRRRRDDDDpppp::::::::eeeennnndddd
              terminates rrdtool and returns rrdtools status ...




                                    - 1 -        Formatted:  August 20, 2003






 RRRRRRRRDDDDpppp((((3333))))                           1111....0000....44445555                            RRRRRRRRDDDDpppp((((3333))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000003333----00007777----22221111



      $$$$RRRRRRRRDDDDpppp::::::::uuuusssseeeerrrr,  $$$$RRRRRRRRDDDDpppp::::::::ssssyyyyssss, $$$$RRRRRRRRDDDDpppp::::::::rrrreeeeaaaallll
              these variables will contain totals of the user time, system
              time and real time as seen by rrdtool.  User time is the time
              rrdtool is running, System time is the time spend in system
              calls and real time is the total time rrdtool has been
              running.

              The difference between user + system and real is the time
              spent waiting for things like the hard disk and new input from
              the perl script.

 EEEEXXXXAAAAMMMMPPPPLLLLEEEE
       use RRDp;
       RRDp::start "/usr/local/bin/rrdtool";
       RRDp::cmd   qw(create demo.rrd --step 100
                     DS:in:GAUGE:100:U:U
                     RRA:AVERAGE:0.5:1:10);
       $answer = RRDp::read;
       print $$answer;
       ($usertime,$systemtime,$realtime) =  ($RRDp::user,$RRDp::sys,$RRDp::real);

 SSSSEEEEEEEE AAAALLLLSSSSOOOO
      For more information on how to use rrdtool, check the manpages.

 AAAAUUUUTTTTHHHHOOOORRRR
      Tobias Oetiker <oetiker@ee.ethz.ch>



























                                    - 2 -        Formatted:  August 20, 2003



