You can list existing git aliases using --get-regexp:
$ git config --get-regexp '^alias\.'
To search aliases, add the following to your .gitconfig under [alias]:
aliases = !git config --list | grep ^alias\\. | cut -c 7- | grep -Ei --color \"$1\" "#"
Then you can:
git aliases - show ALL aliasesgit aliases commit - only aliases containing "commit"