I have installed OWFS and RRDTool on my NSLU2 which is running Debian. I am using the attached script to gather the temperatures and save them to graphs:
If I run the script from the command line as both a user or root, the graph updates correctly. If it runs from the system crontab, it does not update the data, although the graph file time agrees with the cron job. The data shows in the log file that I am piping from the cron job. I thought that this was either a permissions or path problem but I have investigated very carefully and cannot see an issue with either. Has anyone had this happen? If so please steer me in the direction to correct it. Regards, Steve Sykes #!/usr/bin/perl # # copyright Martin Pot 2006-2009 # http://martybugs.net/electronics/tempsensor/ # # rrd_tempsensors.pl use RRDs; # define location of rrdtool databases my $rrd = '/var/lib/rrd'; # define location of images my $img = '/var/www/rrdtool'; # process data for each interface (add/delete as required) &ProcessSensor(0, "sensor 1"); &ProcessSensor(1, "sensor 2"); &ProcessSensor(2, "sensor 3"); sub ProcessSensor { # process sensor # inputs: $_[0]: sensor number (ie, 0/1/2/etc) # $_[1]: sensor description # get temperature from sensor #my $temp = `/usr/bin/digitemp -t $_[0] -q -c /etc/digitemp.conf -o%C`; my $temp = `cat /mnt/1wire/28.DDAB6B020000/temperature | /usr/bin/awk '{print $1}'`; # remove eol chars chomp($temp); print "sensor $_[0]: $temp degrees C ($_[1])\n"; # if rrdtool database doesn't exist, create it if (! -e "$rrd/temp$_[0].rrd") { print "creating rrd database for temp sensor $_[0]...\n"; RRDs::create "$rrd/temp$_[0].rrd", "-s 60", "DS:temp:GAUGE:240:U:U", "RRA:AVERAGE:0.5:1:2016", "RRA:AVERAGE:0.5:6:1344", "RRA:AVERAGE:0.5:24:2190", "RRA:AVERAGE:0.5:144:3650"; } if ($ERROR = RRDs::error) { print "$0: failed to create $_[0] database file: $ERROR\n"; } # check for error code from temp sensor if (int $temp eq 85) { print "failed to read value from sensor $_[0]\n"; $temp = "U"; } # insert values into rrd RRDs::update "$rrd/temp$_[0].rrd", "-t", "temp", "N:$temp"; if ($ERROR = RRDs::error) { print "$0: failed to insert $_[0] data into rrd: $ERROR\n"; } } &CreateGraph($_[0], "day", $_[1]); &CreateGraph($_[0], "week", $_[1]); &CreateGraph($_[0], "month", $_[1]); &CreateGraph($_[0], "year", $_[1]); sub CreateGraph { # creates graph # inputs: $_[0]: n/a # $_[1]: interval (ie, day, week, month, year) # $_[2]: graph description RRDs::graph "$img/temps-$_[1].png", "-s -1$_[1]", "-t DS18S20 temperature sensors :: last $_[1] (1 minute samples)", "--lazy", "-h", "200", "-w", "800", "-l", "0", "-a", "PNG", "-v degrees Celsius", "--slope-mode", "--color", "SHADEA#ffffff", "--color", "SHADEB#ffffff", "--color", "BACK#ffffff", "--color", "CANVAS#ffffff", "DEF:temp0=$rrd/temp0.rrd:temp:AVERAGE", "DEF:temp1=$rrd/temp1.rrd:temp:AVERAGE", "DEF:temp2=$rrd/temp2.rrd:temp:AVERAGE", "LINE2:temp0#33CC00:sensor 1\\: ", "GPRINT:temp0:MIN: Min\\: %5.2lf", "GPRINT:temp0:MAX: Max\\: %5.2lf", "GPRINT:temp0:AVERAGE: Average\\: %5.2lf", "GPRINT:temp0:LAST: Current\\: %5.2lf degrees Celsius\\n", "LINE2:temp1#990000:sensor 2\\: ", "GPRINT:temp1:MIN: Min\\: %5.2lf", "GPRINT:temp1:MAX: Max\\: %5.2lf", "GPRINT:temp1:AVERAGE: Average\\: %5.2lf", "GPRINT:temp1:LAST: Current\\: %5.2lf degrees Celsius\\n", "LINE2:temp2#00FF00:sensor 3\\: ", "GPRINT:temp2:MIN: Min\\: %5.2lf", "GPRINT:temp2:MAX: Max\\: %5.2lf", "GPRINT:temp2:AVERAGE: Average\\: %5.2lf", "GPRINT:temp2:LAST: Current\\: %5.2lf degrees Celsius\\n"; if ($ERROR = RRDs::error) { print "$0: unable to generate sensor $_[0] $_[1] graph: $ERROR\n"; } } -- View this message in context: http://old.nabble.com/RRDTool-graph-not-updating-with-crontab-tp33403549p33403549.html Sent from the RRDTool - User mailing list archive at Nabble.com. _______________________________________________ rrd-users mailing list rrd-users@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
