git hook to run a command after `git pull` if a specified file was changed.In this example it's used to run `npm install` if package.json changed and `bower install` if `bower.json` changed.Run `chmod +x post-merge` to make it executable then put it into `.git/hooks/`.

post-merge

#/usr/bin/env bash
# MIT © Sindre Sorhus - sindresorhus.com

# git hook to run a command after `git pull` if a specified file was changed
# Run `chmod +x post-merge` to make it executable then put it into `.git/hooks/`.

changed_files="$(git diff-tree -r --name-only --no-commit-id ORIG_HEAD HEAD)"

check_run() {
	echo "$changed_files" | grep --quiet "$1" && eval "$2"
}

# Example usage
# In this example it's used to run `npm install` if package.json changed and `bower install` if `bower.json` changed.
#check_run package.json "npm install"
#check_run bower.json "bower install"
check_run Gemfile "bundle"

# then restart the Passenger app either way!
touch tmp/restart.txt 

Changed to work with an old Rails + Bundler + Passenger app on Dreamhost.