System Information

Temperature

Get temperature

sudo vcgencmd measure_temp

Network

Get external IP

curl url ipinfo.io/ip

Storage

Get a specific value

df -h | grep /dev/root | awk '{print $2}'

Memory

Get a specific value from free memory

free -mh | awk 'NR==2{print $4}'

Miscellaneous

Get the size of an specific folder

du -sh /PATH-TO-FOLDER