function zshlibs_update()
{
  zshlibs_log zlibs_update "preparing self update …"
  if [[ -n "$zshlibs_install" ]] 
  then
    zshlibs_log zlibs_update "cd into '$zshlibs_install' …"
    pushd $zshlibs_install 2>&1 > /dev/null
    zshlibs_log zlibs_update "git pull …"
    (
    git pull 2>&1 |zshlibs_log zlibs_update & # > "${HOME}/.log/z_zshlibs_update" &
    )
    zshlibs_log zlibs_update "update done"
    popd 2>&1 > /dev/null
  else
    echo "\$zshlibs_install not set!"
    return 1
    zlibs_install
  fi
}

function zshlibs_boot()
{
  # ensure log directory
  zshlibs_log zbootstrap "ensure directory '${HOME}/.log/'"
  zshlibs_ensure -d "${HOME}/.log/"
}

function zshlibs_ensure()
{
  target=${2}
  typ=${1}
  if ! test -e ${target}
  then
    zshlibs_log zshlibs_ensure "creating '${target}' ($typ) …"
    case $typ in
      -d)
        mkdir -p ${target} \
          || zshlibs_log $0 "unable to create directory '${target}'"  \
          && return 2
        ;;
      -f)
        touch ${target} \
          || zshlibs_log $0 "unable to create file '${target}'" \
          && return 2
    esac
    zshlibs_log zshlibs_ensure "target '${target}' created"
  elif test ${typ} ${target}
  then 
    zshlibs_log zshlibs_ensure "target '${target}' ($typ) present"
    return 0
  else
    zshlibs_log zshlibs_ensure "target '${target}' already exists and it is not a directory"
    return 1
  fi
}

function zshlibs_log()
{
  local facility=$1
  shift
  if [[ -n "${@}" ]]
  then
    echo "$(date -Ins) ${@}" >> "${HOME}/.log/z_$facility.log"
  else
    echo "$(date -Ins) $(cat)" >> "${HOME}/.log/z_$facility.log"
  fi
}

function zshlibs_path_add()
{
  local pathtoadd="${1}"
  zshlibs_log $0 "adding path '$pathtoadd' to \$PATH"
  if [[ ! ${path[(r)${pathtoadd}]} ]]
  then
    path+=(${pathtoadd})
  fi
}

function zshlibs_fpath_add()
{
  local fpathtoadd="${1}"
  zshlibs_log $0 "adding fpath '$fpathtoadd' to \$fpath"
  if [[ ! ${fpath[(r)${fpathtoadd}]} ]]
  then
    path+=(${fpathtoadd})
  fi
}

function zshlibs_start()
{
  zshlibs_boot
  zconfig_boot
  zssh_boot
  zshlibs_update
}

function zbootstrap()
{
  zshlibs_start
}