how to Push an existing repository from command line code example

Example 1: git push existing repo

cd existing_folder
git init
git remote add origin https://gitlab.com/abc.git
git add .
git commit -m "Initial commit"
git push -u origin master

Example 2: how to upload existing project to github

git remote add origin remote repository URL
git remote -v
git push -f origin master

Example 3: git push to another repository

Create a new repo at github.
Clone the repo from fedorahosted to your local machine.
git remote rename origin upstream
git remote add origin URL_TO_GITHUB_REPO
git push origin master
Now you can work with it just like any other github repo. 
To pull in patches from upstream, 
simply run git pull upstream master && git push origin master.