Install latest spook version

install.sh

#!/usr/bin/env bash

### This will download the latest release and put it in PREFIX, the default is /usr/local
### You can run the remote script locally like this:
### curl https://gist.githubusercontent.com/johnae/6fdc84ea7d843812152e/raw/install.sh | PREFIX=~/Local bash

defined () {
    [[ ${!1-X} == ${!1-Y} ]]
}

has_value () {
    if defined $1; then
        if [[ -n ${!1} ]]; then
            return 0
        fi
    fi
    return 1
}

if ! has_value PREFIX; then
  PREFIX=/usr/local
fi

UNAME=$(uname)
ARCH=$(uname -m)
release=$(curl -i https://api.github.com/repos/johnae/spook/releases/latest 2>/dev/null | grep browser_download | grep $UNAME-$ARCH | awk '{print $2}' | sed 's/"//g')
if ! has_value release; then
  echo "No release found for OS $UNAME and arch $ARCH, consider cloning the repo and building it yourself"
else
  echo "Downloading $release..."
  curl -L -o /tmp/spook.gz "$release" 2>/dev/null
  pushd /tmp >/dev/null
  echo "Installing spook..."
  rm -f /tmp/spook
  gunzip spook.gz
  chmod +x spook
  mv -f spook $PREFIX/bin/
  echo "Installed spook in $PREFIX/bin"
  popd >/dev/null
fi