Get Raspberry Pi CPU + GPU temperature with mini script:
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This will create a program to show current CPU and GPU temperatures of the Raspberry Pi 4. You will have needed to have the vcgencmd program all ready working in order for this to work.

Create the file with "sudo nano /usr/bin/temp"

Then in the file input this code:
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#!/bin/bash
# Script: temp
# Purpose: Display the ARM CPU and GPU  temperature of Raspberry Pi 4 
# Original Author: Vivek Gite <www.cyberciti.biz> under GPL v2.x+
# Updated Author: Branden (Personal use only).
cpu=$(</sys/class/thermal/thermal_zone0/temp)
echo "$((cpu/1000))°C"
#Coment out gpu in May 11th, 2021 due to sudo need for web server, as well as remove cpu name above and just put cpu code in motd script or php page.
#echo "GPU => $(vcgencmd measure_temp)"
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save the file then make it executable by:
sudo chmod +x /usr/bin/temp

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Source: https://www.cyberciti.biz/faq/linux-find-out-raspberry-pi-gpu-and-arm-cpu-temperature-command/
Date: April 29th, 2021