How can I automatically be warned if a specific file changes?

Question

I have a php project, and when I pull from another repository and the composer.lock file gets changed, I\'m supposed to run composer.phar install --dev. How can git

Answer 1

Here's an interesting gist: https://gist.github.com/sindresorhus/7996717 I've adapted it for your question.

post-merge git hook is executed when you merge branches or when you do git pull.

post-merge hook (read docs)

#/usr/bin/env bash
# MIT © Sindre Sorhus - sindresorhus.com
# forked by naXa! - naxa.by

# Git hook to run a command after `git merge` / `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" | egrep --quiet "$1" && echo "$2"
}

# In this example it's used to print a warning if composer.lock has been changed
check_run composer.lock "Run `composer.phar install --dev`"

post-checkout git hook is executed when you switch between branches or when you do git rebase.

post-checkout hook (read docs)

#/usr/bin/env bash
# MIT © Sindre Sorhus - sindresorhus.com
# forked by naXa! - naxa.by

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

# terminate gracefully on a file checkout (retrieving a file from the index)
# uncomment the below line if you don't want to run this hook on a file checkout (for example on git->revert in IntelliJ IDEA)
# [ $3 -eq 0 ] && { exit 0; }

changed_files="$(git diff-tree -r --name-only --no-commit-id $1 $2)"

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

# In this example it's used to print a warning if composer.lock has been changed
check_run composer.lock "Run `composer.phar install --dev`"

exit 0;

You may notice that I've changed grep to egrep here. It is done in order to be able to search using a fancy expression. For example "file1.txt|file2.txt" where | is used as an OR operator.