git diff command causes code example
Example 1: git diff two commits one file
$ git diff HEAD^^ HEAD main.c
$ # show diff between HEAD(current commit) and HEAD^^(two commits back) for main.c
Example 2: git diff files only
Just specify your local branch1 or remote origin/branch2
git diff branch1 origin/branch2 #show diff referenced from second branch
git diff branch1 branch2 file.txt #show diff only between file.txt