git diff revision of branch code example

Example 1: make diff git as commit

A simple way to do it is:

create and checkout branch tmp at branch_a (git branch tmp branch_a && git checkout tmp)
git reset --soft branch_b
git commit
that commit must have all the diff

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