git-hub.sh

#!/bin/sh

_tmp="$( mktemp --tmpdir -- git-hub.XXXXXXXX )"
trap 'rm "$_tmp";' EXIT HUP INT ABRT TERM

curl -s "https://api.github.com/repos/$1" > "$_tmp" || exit 1

jq . >> /dev/null < "$_tmp" || {
    echo "Malformed JSON."
    exit 1
  }

origin="$( jq -r .clone_url < "$_tmp" )"
test "$origin" = "null" && {
    echo "No clone URL"
    exit 2
  }

if [ "$( jq -r .parent < "$_tmp" )" != "null" ]; then
  upstream="$( jq -r .parent.clone_url < "$_tmp" )"
  test "$upstream" = "null" && {
      echo "Upstream present but no clone URL"
      exit 2
    }
fi

if [ "$2" = "" -o "$2" = "." ]; then
  target="$( readlink -fe "." )"
else
  mkdir --parent "$2" || exit 1
  target="$( readlink -fe "$2" )"
fi

git clone "https://${1%/*}@${origin#https://}" "$target" || {
    echo "Unable to clone repository '$origin'"
    exit 3
  }

if [ "$upstream" ]; then
  cd "$target" && \
  git remote add upstream "$upstream" && \
  git fetch upstream && \
  git branch upstream && \
  git branch -fu upstream/master upstream
fi