Backing up your Homebrew packages
Update: while this is a good template to do a quick backup, a more flexible solution exists in the Brew Bundle project. Thanks @MacHomebrew for the pointer!
It’s a good idea to keep track of what packages you’ve got installed in Homebrew - good for provisioning a new Mac, good for recovering from a disaster.
To get a list of the current packages is as simple as
but that gives us everything, dependencies and all. If we just want what we explicitly installed, we should go for
like the leaves of our dependency tree.
Just pipe that out into a file
brew leaves > homebrew-packages.txt
for safekeeping and get it under version control along with the rest of you configuration files.
When it comes to recovery, we can save time and effort by using
xargs to pipe
out each of the lines as an argument to
cat homebrew-packages.txt | xargs brew install
and everything will (re)install in one go. It may take some time.
Maybe you want to add to the list from one machine without overwriting the current list? I just did (for one reason or another), and it’s fairly easy to handle. Instead of overwriting the text file, append to the end of it
brew leaves >> homebrew-packages.txt
Now you might have some repetitions in that file - get rid of them with
sort homebrew-packages.txt | uniq
This sorts the original list into order, then removes any lines that are repetitions of the one before, leaving only one. Pipe that out to a new file
sort homebrew-packages.txt | uniq > homebrew-packages-reconciled.txt
and overwrite the old one if you need to (just don’t do it in the pipe - it doesn’t like it and the file becomes blank. Boo.)
Did I mention that Text Processing with Ruby was an amazing book? I worked out how to do the above from what I read in the section on Unix tools. Nice.