Sign in GitHub using SSH
1. Generate ssh key
code:sh
$ ssh-keygen -t rsa
Enter file in which to save the key: ~/.ssh/id_rsa_github
Enter passphrase: # no password
2. Write ssh config
code:~/.ssh/config
Host github.com
HostName github.com
User git
IdentityFile ~/.ssh/id_rsa_github
3. Write public key on GitHub