git 查看当前与上一次version的差异

As pointed out on a comment by amalloy, if by "current and last versions" you mean the last commit and the commit before that, you could simply use

git show

Assuming "current version" is the working directory (uncommitted modifications) and "last version" is HEAD (last committed modifications for the current branch), simply do

git diff HEAD

credit for following goes to user Cerran

And if you always skip the staging area with -a when you commit, then you can simply use git diff.

Summary

1. git diff shows unstaged changes.
2. git diff --cached shows staged changes.
3. git diff HEAD shows all changes (both staged and unstaged).

Source: git-diff(1) Manual Page – Cerran