*require* bash function

.bashrc

function is_installed() {
  local installed=$(dpkg -s "$1" 2>&1 | grep 'install ok installed')
  if [ "" == "$installed" ] ; then
    return 1
  fi  
  return 0
}

function require() {
  UNAME="$(uname)"
  case $UNAME in
    MINGW*)
      echo "MinGW not supported"
      return 0
      ;;  
    Linux|*)
      echo "require $1"
      if ! is_installed $1 ; then
        echo "$1 not installed yet!"
        sudo apt-get install $1
        return $?
      fi  
      ;;  
  esac
}