`ipcalc` is a terminal tool that lets you validate an IP address. This proves useful to me as I have scripts that automate certain remote tasks given an IP address. Instead of trusting that an argument passed is a valid IP, why not check it?
First the script would need to check if `ipcalc` exists.
```bash
if ! command -v ipcalc > /dev/null ; then
echo "ipcalc not found. Exiting..."
exit 1
fi
```
Now for this example, we'll validate an IP address stored in the variable `$IP`.
