Shell Programming and Scripting

#!/usr/bin/perl
#
# copyright Per Hansen 2009
#
#
# temp.pl

use lib qw(/opt/rrdtool-1.4.1/lib/perl);
use RRDs;
 

# sti til rrdtool databases
my $rrd = '/var/lib/rrd';



# sti til færdige grafer
my $img = '/var/www/rrdtool';



# sti til digitemp
my $digi = '/usr/bin'; 
 

# hvis rrd-database ikke findes, laves den her
    if (! -e "$rrd/temperature.rrd") 
    {
        print "creating rrd database for sensors ...\n";
        RRDs::create "$rrd/temperature.rrd",
         "-s 300",        
         "DS:out:GAUGE:600:-50:50",
         "DS:in:GAUGE:600:-50:50",            
         "RRA:AVERAGE:0.5:1:600",
         "RRA:AVERAGE:0.5:6:700",
         "RRA:AVERAGE:0.5:24:775",        
         "RRA:AVERAGE:0.5:288:797",
         "RRA:MIN:0.5:1:600",
         "RRA:MIN:0.5:6:700",
         "RRA:MIN:0.5:24:775",
         "RRA:MIN:0.5:288:797",
         "RRA:MAX:0.5:1:600",
         "RRA:MAX:0.5:6:700",
         "RRA:MAX:0.5:24:775", 
         "RRA:MAX:0.5:288:797" ;
   }
    if ($ERROR = RRDs::error) { print "$0: failed to create temperature database file: $ERROR\n"; }
 
    
# aflæs den udendørs-sensor
    my $read_out = `$digi/digitemp -t 0 -q -c /etc/digitemp.conf -o%C`;
       
    # aflæs kælder-sensor
    my $read_in = `$digi/digitemp -t 1 -q -c /etc/digitemp.conf -o%C`;
 
    
# fjerner eol-karaktere i den læste værdi
    chomp($read_out);
    chomp($read_in);
 
    
# check for fejl i temp-sensorerne
    if (int $read_out eq 85)
    {
        print "failed to read value from outside sensor\n";
        $read_out = "U";
    }
    if (int $read_in eq 85)
    {
        print "failed to read value from basement sensor\n";
        $read_in = "U";
    }
  

  # indsæt værdier i rrd
    RRDs::update "$rrd/temperature.rrd",
       "-t", "out", "N:$read_out";
       "-t", "in",    "N:$read_in";
 
    
if ($ERROR = RRDs::error) { print "$0: failed to insert data into rrd: $ERROR\n"; }
 
    
#print"out $read_out";
    #print"in $read_in";  
 

# generer graf
RRDs::graph "$img/temp-day.png",
"-n", "DEFAULT:0:/usr/share/fonts/truetype/msttcorefonts/arial.ttf", 
"-t Temperaturer i Auning, Danmark °C", 
"--lazy",
"-a", "PNG",
"-h", "80", "-w", "550", 
"-E",
"DEF:outside=$rrd/temperature.rrd:out:AVERAGE",
"DEF:basement=$rrd/temperature.rrd:in:AVERAGE",
"COMMENT:\\c",
"COMMENT:             MAX            MIN            AVERAGE          CURRENT\\c",
"LINE2:outside#FF0000:udendørs\\t",
"GPRINT:outside:MAX:%4.2lf °C\t",
"GPRINT:outside:MIN:%4.2lf °C\t",
"GPRINT:outside:AVERAGE:%4.2lf °C\t",
"GPRINT:outside:LAST:%4.2lf °C\\c",
"LINE2:basement#3333CC:kælder\\t",
"GPRINT:basement:MAX:%6.2lf °C\t",
"GPRINT:basement:MIN:%6.2lf °C\t",
"GPRINT:basement:AVERAGE:%6.2lf °C\t",
"GPRINT:basement:LAST:%6.2lf °C\\c",
"COMMENT:\\c",
"COMMENT:Copyright Per Hansen\\c";

  if ($ERROR = RRDs::error) { print "$0: unable to generate sensor $_[0] $_[1] graph: $ERROR\n"; }

    RRDs::update "$rrd/temperature.rrd",
       "-t", "out", "N:$read_out";
       "-t", "in",    "N:$read_in";

RRDs::update ("$rrd/temperature.rrd", "N:" . $read_out. ":" .$read_in);