Update several self-hosted Wordpress blogs at once on Dreamhost

wp-upgrade.sh

#!/bin/bash

cd $HOME

# Add here every domain/folder where you have Wordpress installed.
# Dreamhost normally puts all domains on $HOME, so this is what I do.
DOMAINS="mydomain1.com mydomain2.com mydomain3.com"

# Add here any dirs, file patterns etc. that you don't want to backup before upgrading.
# These are MY settings; tweak according to your needs.
cat << EOF > tar_exclusions
*.mp3
*.ogg
*.alp
*.zip
EOF

mkdir -p backup

printf "\nUpdating Wordpress on all domains:\n\n"
printf "- Downloading the latest version of WP... "
wget -q -c http://wordpress.org/latest.tar.gz || exit 1
printf "ok!\n\n"

for domain in $DOMAINS; do
  printf "- Backing up $domain "
  tar czf "backup/$domain-$(date +%F).tar.gz" \
    -X tar_exclusions \
    "$domain" || exit 1
  printf "ok!\n"
  printf "- Updating $domain "
  ln -s $domain wordpress && printf '. ' && \
  tar xzf latest.tar.gz && printf '. ' && \
  rm -f wordpress && printf '. ' && \
  printf "ok!\n\n"
done

rm -f latest.tar.gz tar_exclusions