backup Homebrew packages. See http://www.topbug.net/blog/2013/12/07/back-up-homebrew-packages/

backup-homebrew.sh

#!/bin/bash

echo '#!/bin/bash'
echo ''
echo 'failed_items=""'
echo 'function install_package() {'
echo 'echo EXECUTING: brew install $1 $2'
echo 'brew install $1 $2'
echo '[ $? -ne 0 ] && $failed_items="$failed_items $1"  # package failed to install.'
echo '}'

brew tap | while read tap; do echo "brew tap $tap"; done

brew list | while read item;
do
  echo "install_package $item '$(brew info $item | /usr/bin/grep 'Built from source with:' | /usr/bin/sed 's/^[ \t]*Built from source with:/ /g; s/\,/ /g')'"
done

echo '[ ! -z $failed_items ] && echo The following items were failed to install: && echo $failed_items'

This is great. I also use Homebrew Cask and noticed those packages weren't getting picked up in the restore file so I added this to the script before the last echo line:

echo 'function install_cask_package() {'
echo 'echo EXECUTING: brew cask install $1'
echo 'brew cask install $1'
echo '[ $? -ne 0 ] && $failed_items="$failed_items $1"  # package failed to install.'
echo '}'

brew cask list | while read item;
do
  echo "install_cask_package $item"
done

@crcastle Thanks! Would you mind me putting the improvements into the blog post and this gist?

@xuhdev really sorry I missed this message from you. Here are the improvements: https://gist.github.com/crcastle/6eb329de90a27b1e2ed7. I run this every 6 hours via cron. I also write the generated restore script to a folder in my Dropbox so that I get no-touch back ups. Good in case my computer dies or is stolen.