VARPWD=P@ssw0rd; HASH=`echo -n $VARPWD | sha1sum`; curl --silent https://api.pwnedpasswords.com/range/`cut -b 1-5 <(echo $HASH)` --stderr - | grep -i `cut -b 6- <(echo $HASH) | cut -d ' ' -f 1`

If it doesn't return anything than your password isn't in the list. You should probably start your line with a space so that it isn't recorded in your bash_history.

If someone else can make it better or shorter, be my guest.