My file looks like this
#Default GitHub
Host github.com
#Username username2
HostName github.com
User git
IdentityFile ~/.ssh/id_rsa_username2
Host github-username1
#Username username1
HostName github.com
User git
IdentityFile ~/.ssh/id_rsa_username1
I'd like to find the first username after github.com
so it would return in this case, username2
.