Introduces a command `gh` to clone your repos in a few keystrokes

gh_clone.sh

# Fast command-line cloning of GitHub repos
#
# usage: add to your .bashrc or .zsh like this:
# source gh_clone.sh

# replace 'jlumbroso' with your own GitHub username
export GITHUB_USERNAME="jlumbroso"

# one-line repo clone
# gh <repo>       [<-- will default to username=${GITHUB_USERNAME}]
# gh <username> <repo>
function gh {
    username=${1:?"The repo must be specified."}
    repo=${2}
    if [ -z "$repo" ]; then
        repo=${username}
        username=${GITHUB_USERNAME}
    fi

    git clone https://github.com/${username}/${repo}.git
}