This is a recipe to find out the operating temperature of your Raspberry Pi.
On the command line type after the '%' prompt:
% vcgencmd measure_tempIt will return with the temperature, e.g.:
temp=47.2'C
The vcgencmd command merely reads the value of a single line in a file written by the Raspberry Pi OS, a file located at:
/sys/class/thermal/thermal_zone0/temp
Divide the value found there by 1000 to get the ARM CPU temperature in more human readable format. Here's the bash script to do that:
cpu=$(</sys/class/thermal/thermal_zone0/temp) echo "$((cpu/1000)) c"