http://dev.mensfeld.pl/2013/04/backup-mysql-dump-all-your-mysql-databases-in-separate-files/

backup-mysql

#!/bin/bash
#
# Usage:
# 1. Change the values in Config
# 2. $ sudo chmod 700 backup-mysql
# 3. $ sudo mv backup-mysql /etc/cron.daily/

## Config

MYSQL=/usr/bin/mysql
MYSQLDUMP=/usr/bin/mysqldump
TIMESTAMP=$(date +%Y%m%d)
BACKUP_DIR="/backup/$TIMESTAMP"
MYSQL_USER="backup"
MYSQL_PASSWORD="password"

##

mkdir -p "$BACKUP_DIR/mysql"
 
databases=`$MYSQL --user=$MYSQL_USER -p$MYSQL_PASSWORD -e "SHOW DATABASES;" | grep -Ev "(Database|information_schema)"`

for db in $databases; do
  $MYSQLDUMP --force --opt --user=$MYSQL_USER -p$MYSQL_PASSWORD --databases $db | gzip > "$BACKUP_DIR/mysql/$db.gz"
done