Commit for Another

You can make Alice the author, while you are still the commiter:

1name="Alice Bobinson"
2email="alice@email.com"
3
4git add ${file}
5git commit --author="${name} <${email}>"

Or, make Alice both the committer and the author:

1git -c user.name="${name}" -c user.email="${email}" commit -m "${message}"