git show username

git config --global --get user.name
git config --global --get user.email

git config user.name
git config user.email

$ git config --global user.name
> "John Smith"

$ git config --global user.email 
> "[email protected]"

if you have configured multiple git users in your machine
$ git config --global user.name ### It will give name of git user who is globaly scoped
$ git config user.name ### It will give name of git user who has scope with respect to current repository

git config --global user.name "My Name"

git config --list

git config user.name