cherry_pick_upstream_homebrew_formulas.sh

#!/bin/sh

## This script imports (cherry-picks) commits from HomeBrew into LinuxBrew.
##
## This script automatically find the commits which updates ONLY
## formulas in "/Library/Formulas" from HomeBrew,
## and cherry-pick them into a new branch.
##
## It is assumed that the current directory is setup in the following way:
##
##    # Your forked LinuxBrew repository:
##    $ git clone https://github.com/agordon/linuxbrew.git
##
##    # Add LinuxBrew as 'upstream'
##    git remote add upstream https://github.com/Homebrew/linuxbrew.git
##
##    # Add HomeBrew as 'upstream_homebrew'
##    git remote add upstream_homebrew https://github.com/Homebrew/homebrew.git
##
##
##
##

BRANCH=homebrew_import_$(date +%F-%H%M%S)

git checkout -b "$BRANCH" upstream/master || exit 1

git fetch upstream # upstream for us is LinuxBrew
git fetch upstream_homebrew # the Mac OS-X homebrew

## Find the differences between LinuxBrew and HomeBrew
##
## The git format "---%n%H" will produce the following output:
##
##    ---
##    9fe155d2690064eae442aa340d1a8b0e2b51dd60
##    1       0       Library/Formula/libmemcached.rb
##
##    ---
##    3bb66a90bf3b2338ce4159fb62157f67acee7754
##    7       0       Library/Formula/libmemcached.rb
##
##    ---
##    2609f61fa41fe67248127facf76c9daef9ccf757
##    30      11      Library/Formula/libmemcached.rb
##
##    ---
##
##

( git log --pretty=format:"---%n%H" --no-abbrev-commit --numstat \
	upstream/master..upstream_homebrew/master ; echo --- ) |
	awk '$0 == "---" { if (commit_sha1 && formula_commit) {
				print commit_sha1
			   }
			   formula_commit = 1
	                  }

             length($0)==40 && $0 ~ /^[0-9a-f]*$/ { commit_sha1 = $0 }

	     NF==3 { insertions = $1
                     deletions = $2
                     filename = $3
		     i = index(filename,"Library/Formula/")
		     if ( i != 1 ) {
                        # This commit has at least one changed file
                        # which is not a formula, do not use it
                        formula_commit = 0
                     } }' | tac | xargs -I{} git cherry-pick {}

echo "Done!"
echo "The imported branch is:"
echo "   $BRANCH"
echo ""
echo "To push it back to github:"
echo "   git push origin $BRANCH"
echo ""
echo "Then send a Pull-Request on GitHub"