drpl_multisite_backup.sh

#!/bin/sh
MYSQLDUMP_DIR='/Users/blah/Sites/db_backups'
CURDATE=`date +%F`

for SITE in $(ls sites/)
do
  if [[ -f sites/${SITE}/settings.php ]]
  then
    # Retreive DB information from settings.php file
    DBURL=$(grep '^$db_url' sites/${SITE}/settings.php | sed "s#.*'\(.*\)'#\1#")

    DBUSER=$(echo ${DBURL} | sed 's#.*//\(.*\)\:.*@.*#\1#')
    DBPASS=$(echo ${DBURL} | sed 's#.*//.*\:\(.*\)@.*#\1#')
    DBNAME=$(echo ${DBURL} | sed "s#.*//.*@.*/\(.*\)\;#\1#")

    DBHOST=$(echo ${DBURL} | sed 's#.*//.*@\(.*\)/.*#\1#')

    if [[ "$(echo ${DBHOST#*:})" != "${DBHOST}" ]]
    then
      DBPORT=$(echo "-P ${DBHOST#*:}")
      DBHOST=$(echo ${DBHOST%:*})
    fi

    # Backup current database
    echo "mysqldump -h ${DBHOST} ${DBPORT} -u${DBUSER} -p ${DBNAME} > ${DBNAME}_${CURDATE}.sql"
    mysqldump -h ${DBHOST} ${DBPORT} -u${DBUSER} -p${DBPASS} ${DBNAME} > ${MYSQLDUMP_DIR}/${DBNAME}_${CURDATE}.sql
  fi
done