RRDp(3)                             RRDtool                            RRDp(3)



NNAAMMEE
       RRDp - Attach rrdtool from within a perl script via a set of pipes;

SSYYNNOOPPSSIISS
       use RRRRDDpp

       RRRRDDpp::::ssttaarrtt _p_a_t_h _t_o _r_r_d_t_o_o_l _e_x_e_c_u_t_a_b_l_e

       RRRRDDpp::::ccmmdd  _r_r_d_t_o_o_l _c_o_m_m_a_n_d_l_i_n_e

       $answer = RRRRDD::::rreeaadd

       $status = RRRRDD::::eenndd

       $$RRRRDDpp::::uusseerr,  $$RRRRDDpp::::ssyyss, $$RRRRDDpp::::rreeaall

DDEESSCCRRIIPPTTIIOONN
       With this module you can safely communicate with the rrdtool.

       After every RRRRDDpp::::ccmmdd you have to issue an RRRRDDpp::::rreeaadd command to get
       rrrrddttoooolls 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, RRRRDDpp::::rreeaadd will return an undefined variable.

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

       use RRRRDDpp
               Load the RRDp::pipe module.

       RRRRDDpp::::ssttaarrtt _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

       RRRRDDpp::::ccmmdd _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 = RRRRDDpp::::rreeaadd
               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 = RRRRDDpp::::eenndd
               terminates rrdtool and returns rrdtools status ...

       $$RRRRDDpp::::uusseerr,  $$RRRRDDpp::::ssyyss, $$RRRRDDpp::::rreeaall
               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.

EEXXAAMMPPLLEE
        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);

SSEEEE AALLSSOO
       For more information on how to use rrdtool, check the manpages.

AAUUTTHHOORR
       Tobias Oetiker <oetiker@ee.ethz.ch>



1.0.49                            2004-08-08                           RRDp(3)
