git hook to run a command after `git pull` if a specified file was changed.In this example it's used to run `composer install` if `composer.lock` 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 `composer install` if `composer.lock` changed.
check_run composer.lock "composer install"
#check_run bower.json "bower install"