git check diff in file code example
Example 1: git diff of a file between two commits
git diff <branch_hash> <other_branch_hash> -- <file_path>
Example 2: 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 3: git diff between one file
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