Backup all databases at once with one shell script.

backup-all-databases.sh

#!/bin/bash
# Backup all available databases

USERNAME="root";
PASSWORD="password";

for DATABASE in `mysql -u${USERNAME} -p${PASSWORD} -e "SHOW DATABASES;"`
do
    echo mysqldump --routines -u${USERNAME} -p${PASSWORD} ${DATABASE} \> ${DATABASE}.dmp;
    mysqldump --routines -u${USERNAME} -p${PASSWORD} ${DATABASE} > ${DATABASE}.dmp;
done;