addpath.sh

typeset -U path
typeset -U manpath

function addpath {
  [[ -d "$1" ]] && path=("$1" $path)
  [[ -d "${1:h}/sbin" ]] && path=("${1:h}/sbin" $path)
  for d in "${1:h}"/{man,share/man}; do
    [[ -d "$d" ]] && manpath=("$d" $manpath)
  done
}

addpath /usr/local/bin
addpath /usr/local/sbin
addpath ~/.rbenv/bin
addpath $HOME/bin
...