====== Plotta temperaturer från Webswitch ======
===== Hämta data från webswitch =====

The script below collect the temperature data from the webswitch and saves it in a file.
After that the data is plotted with the gnuplot scripts.

The script is named temp_webswitch in the example below.

   #!/bin/bash
   #
   # Small script to read and plot temperature
   # 
   # 1)Save timestamp
   # 2)Retrieve Outdoor temperature
   # 3)Retrieve Indoor Temperature
   # 4)Save time, outdoortemp, indoor temp to file tempdata
   # 5)plot three figures
   #
   DATE=$(date +"%s" )
   UTE=$(curl -s "http://xxxxxx.shacknet.nu:xxxx/temp.egi" | perl -e 'foreach (<>){if(/Current Temp B/){($x)=/Current Temp B.+TD> (.+) C</;print "$x\n";}}')
   INNE=$(curl -s "http://xxxxxx.shacknet.nu:xxxx/temp.egi" | perl -e 'foreach (<>){if(/Current Temp A/){($x)=/Current Temp A.+TD> (.+) C</;print "$x\n";}}')
   echo "$DATE   $UTE    $INNE" >> /home/sm3sgp/temp/tempdata
   /usr/bin/gnuplot "/home/xxxxx/temp/plot.gnu"
   /usr/bin/gnuplot "/home/xxxxx/temp/plot24.gnu"
   /usr/bin/gnuplot "/home/xxxxx/temp/plotweek.gnu"
===== Plot the figures =====

The scripts plot.gnu, plot24.gnu and plotweek.gnu can be modified to plot a specific time period per figure.
It generates a small .png file.

   #
   # Plot the number of lines specified in the tail command below.
   #
   set terminal png
   set output "/home/xxxxx/temp/tempweek.png"
   set grid
   set ytics 5
   set xdata time
   set timefmt "%s"
   set format x "%R"
   set yrange [-10:35]
   plot "< tail -550 /home/xxxxx/temp/tempdata" using 1:2 with lines title "Temperatur utomhus", "< tail -550 /home/xxxxx/temp/tempdata" using 1:3 with lines title "Temperatur inomhus"

===== Run a crontab job =====

Edit the crontab file with command:
crontab -e

   # m h  dom mon dow   command
   1-59/2 * * * * /home/xxxxx/temp/temp_webswitch &> /dev/null