求教如何设置 zsh 补全

[1423]

比如运行 brew info youtube-dl，下面显示

youtube-dl: stable 2015.02.11 (bottled), HEAD
http://rg3.github.io/youtube-dl/
/usr/local/Cellar/youtube-dl/2015.02.11 (8 files, 948K) *
  Poured from bottle
From: https://github.com/Homebrew/homebrew/blob/master/Library/Formula/youtube-dl.rb
==> Dependencies
Optional: rtmpdump ✘
==> Options
--with-rtmpdump
    Build with rtmpdump support
--HEAD
    Install HEAD version
==> Caveats
To use post-processing options, `brew install ffmpeg` or `brew install libav`.

Bash completion has been installed to:
  /usr/local/etc/bash_completion.d

zsh completion has been installed to:
  /usr/local/share/zsh/site-functions

问题是我知道 zsh completion has been installed to xxx 了，那怎么使用呢？

搜索了好久，只找到一个说似乎与 fpath 有关，但我的 fpath 含有 /usr/local/share/zsh/site-functions 了

[jprovim]

http://stackoverflow.com/questions/14970728/homebrews-git-not-using-completion

或者自己source下就好.

[gt11799]

https://github.com/robbyrussell/oh-my-zsh
有现成的，用就好。

[1423]

@gt11799 那我用的是 zsh 怎么办？正如 http://stackoverflow.com/questions/14970728/homebrews-git-not-using-completion#comment21020890_14970926 所说的。

[1423]

@jprovim 直接 source 提示 can only be called from completion function ，求教怎么正确的 source

[msg7086]

@1423 oh-my-zsh不算zsh么……