How to merge just one file from a another branch with Git

merge_only_one_file_from_another_branch.sh

## Lets suppose that we want to merge path/to/my/file.txt from branch_a into branch_b

# We start in branch_b
git checkout branch_b

# We create an intermediate branch
git checkout -b intermediate_branch

# We merge merge_a into that
git merge branch_a

# We go back to branch_b and get the merged file
git checkout branch_b
git checkout intermediate_branch path/to/my/file.txt