How to read keyboard input in git hook in sourcetree

[Ron Newsham]

We are trying to implement a soft code freeze system for our development branch in git.

Basically, if `readme.md` (a file that is guaranteed to be available in our repository) is locked:

`git lfs lock readme.md`

the the `pre-push` hook checks the branch and rejects push to `develop` branch.

We need the ability to override this in SourceTree, so the simple solution seems to be to prompt the user to override the check if and only if `readme.md` is locked and we are pushing to `develop`.

However, I cannot find a way (push via UI or a custom action to lauch bash/cmd in a new window) to read `/dev/tty` during script operation, other than launching a terminal window.

Note: running a terminal to `git push origin` is not an acceptable use case.

Update: corrected to use `/dev/tty' rather than `stdin`