I have recently moved from SVN to Git and am a bit confused about something. I needed to run the previous version of a script through a debugger, so I did git checkout <previous version hash> and did what I needed to do.

Now I want to get back to the newest version, but I don't know the hash for it. When I type git log, I don't see it.

How can I do this? Also, is there an easier way to change versions than by typing out hashes - something like "go back two versions" or "go to the most chronologically recent"?

git checkout master should do the trick. To go back two versions, you could say something like git checkout HEAD~2, but better to create a temporary branch based on that time, so git checkout -b temp_branch HEAD~2