Github – How to reference a commit in an issue comment on GitHub

What you need to do is to create a new commit with the same details as the current HEAD commit, but with the parent as the previous version of HEAD. git reset --soft will move the branch pointer so that the next commit happens on top of a different commit from where the current branch head is now.

# Move the current head so that it's pointing at the old commit
# Leave the index intact for redoing the commit.
# HEAD@{1} gives you "the commit that HEAD pointed at before 
# it was moved to where it currently points at". Note that this is
# different from HEAD~1, which gives you "the commit that is the
# parent node of the commit that HEAD is currently pointing to."
git reset --soft HEAD@{1}

# commit the current tree using the commit details of the previous
# HEAD commit. (Note that HEAD@{1} is pointing somewhere different from the
# previous command. It's now pointing at the erroneously amended commit.)
git commit -C HEAD@{1}

If you want only the remote URL, or if your are not connected to a network that can reach the remote repo:

git config --get remote.origin.url

If you require full output and you are on a network that can reach the remote repo where the origin resides :

git remote show origin

When using git clone (from GitHub, or any source repository for that matter) the default name for the source of the clone is "origin". Using git remote show will display the information about this remote name. The first few lines should show:

C:\Users\jaredpar\VsVim> git remote show origin
* remote origin
  Fetch URL: git@github.com:jaredpar/VsVim.git
  Push  URL: git@github.com:jaredpar/VsVim.git
  HEAD branch: master
  Remote branches:

If you want to use the value in the script, you would use the first command listed in this answer.