I'm using MRTG to grab data from sensors of a ubuntu server 12.04, with this script.

UPTIME=$(uptime | awk -F, '{print $3}' )
TEXT="Graphic Card Temperature"

GPCTEMP1=$( ${SENSORS} | grep "temp1" | awk '{print int($3)}' )

# http://people.ee.ethz.ch/~oetiker/webtools/mrtg/reference.html
# "The external command must return 4 lines of output:
# Line 1
# current state of the first variable, normally 'incoming bytes count'
# Line 2
# current state of the second variable, normally 'outgoing bytes count'
# Line 3
# string (in any human readable format), telling the uptime of the target.
# Line 4
# string, telling the name of the target. "

echo ${GPCTEMP1}
echo ${GPCTEMP1}
echo ${UPTIME}
echo ${TEXT}

Unfortunally there is two "temp1" when I run sensors there is two sensors with the name "temp1"

/etc/mrtg/cfg/mrtg-scripts$ sensors
    Adapter: SMBus I801 adapter at f000
    in0:          +1.12 V  (min =  +0.00 V, max =  +3.31 V)
    Vcore:        +1.09 V  (min =  +0.00 V, max =  +2.99 V)
    +3.3V:        +3.25 V  (min =  +2.96 V, max =  +3.61 V)
    +5V:          +5.03 V  (min =  +4.48 V, max =  +5.50 V)
    +12V:        +11.90 V  (min =  +0.00 V, max = +15.69 V)
    in5:          +2.10 V  (min =  +0.00 V, max =  +4.48 V)
    fan1:        1312 RPM  (min =    0 RPM)
    fan2:           0 RPM  (min =    0 RPM)
    fan3:           0 RPM  (min =    0 RPM)
    fan4:           0 RPM  (min =    0 RPM)
    temp1:        +38.5°C  (low  =  +5.0°C, high = +65.0°C)
                           (crit = +70.0°C, hyst = +66.0°C)
    M/B Temp:     +39.8°C  (low  =  +5.0°C, high = +65.0°C)
                           (crit = +70.0°C, hyst = +66.0°C)
    temp3:        +42.2°C  (low  =  +5.0°C, high = +65.0°C)
                           (crit = +70.0°C, hyst = +66.0°C)

Adapter: ISA adapter
Core 0:       +59.0°C  (high = +74.0°C, crit = +100.0°C)
Core 1:       +55.0°C  (high = +74.0°C, crit = +100.0°C)
Core 2:       +55.0°C  (high = +74.0°C, crit = +100.0°C)
Core 3:       +57.0°C  (high = +74.0°C, crit = +100.0°C)

Adapter: PCI adapter
temp1:        +60.5°C

I want to grab the information of the radeon-pci-0100, but how can I do that?

This is the result when I use sensors with grep

/etc/mrtg/cfg/mrtg-scripts$ sensors | grep "temp1"
    temp1:        +38.8°C  (low  =  +5.0°C, high = +65.0°C)
    temp1:        +60.5°C

2 Answers 2


Well, the simplest approach would be to just grab the last line:

sensors | grep temp1 | tail -n 1 | awk '{print int($3)}' 

tail -n 1 prints the last line of the file.


sensors | tac | grep -m 1 temp1 | awk '{print int($3)}' 

tac reverses it's input so the 1st line is now the last. That means that the first match for temp1 is the one you care about and since grep -m 1 will print only the first match, that's what you will get.

Personally, since you're using awk already, I'd do the whole thing in awk:

sensors | awk '/temp1/{k=int($2)}END{print k}

The idea here is that each time a line matches temp1, k is set to int($2). However, k is only printed in the END{} block which is executed after the rest of the file has been processed so only the last value found will be printed.

  • This was a the class and you was the teacher! very good answer, every choice worked like a charm! just a append is that some times I had to use '{print int($2)}' because it was returning me just 0 with $3` Jul 3, 2014 at 17:49

The easiest answer is to install mrtgutils-sensors, which includes the mrtg-sensors package that automatically parses the output of sensors.

mrtg-sensors radeon-pci-0100 temp1 

will give you the correct answer.

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