I'm a beginner in scripting. I have a temperature sensor which gives me temperature if I cat the file /sys/bus/w1/devices/28-000006c5772c/w1_slave.
The output of the file looks like:
83 01 4b 46 7f ff 0d 10 66 t=24187
As you can see the temperature is t=24187 which I have to divide by 1000.
My script looks like this:
#!/bin/bash
date +%Y-%m-%d-%H-%M
s= cat /sys/bus/w1/devices/28-000006c5772c/w1_slave | grep t= | cut -d "=" -f2
x= 1000
f= echo $(( $s / $x )) | bc -l
echo the actually temperature is $f
But it dosen´t work. When I start the script, I get this output here:
2015-05-04-08-51 (date is wrong NTP not configured^^)
23687
/home/pi/RAB.sh: line 5: 1000: command not found
/home/pi/RAB.sh: line 6: / : syntax error: operand expected (error token is "/ ")
To assign the output of a command to a variable, you need to use the backticks or (preferably) the $() syntax.
s=$(cat /sys/bus/w1/devices/28-000006c5772c/w1_slave | grep t= | cut -d "=" -f2)
will set $s to 24187
That, and removing the spaces after the = signs as suggested by chepner will get you what you want.