Test if the current directory is inside a Rails project (bash)

Question

Is there an easy way to test if the current directory is inside a rails project? Clearly Rails itself tests this in order to use the rails subcommands (generate, scaffold, etc.), so presumably there's a straight-forward way to test this.

I'm looking for something similar to how you would test if you're inside a Git repo.

Answer 1

I know you already have a solution in ruby, but here's one written in bash, which should be a bit faster.

Assuming you're using Bundler:

grep 'rails' 'Gemfile' >/dev/null 2>&1
if [ $? -eq 0 ]; then
  echo "It's a Rails project!"
fi

This is what that snippet does:

1. Grep the Gemfile in the current directory for 'rails'. Discard grep's output.
2. If grep exits with exit code 0, you're in a Rails project

grep 'rails' 'Gemfile' will return a status code of 2 if a file named 'Gemfile' doesn't exist in the current directory. grep will return a status code of 1 if the found a 'Gemfile' but it doesn't contain 'rails'.

For Rails 2 without Bundler this should work:

if [ -f script/rails ]; then
  echo "It's a Rails 2 project!"
fi

All that does is test if the script/rails file exists.

I hope this helps someone who's hoping to do it bash instead of ruby.

Answer 2

There are no file or directory specific to Rails. so you can't really know if you are or not in a rails directory.

The better solution can be to know if you have rails or railities gem dependencies in your Gemfile.

bundle list | grep 'rail'