建立自已的 homebrew

GitHub 作為地表上最受歡迎原始碼代管平台 1，自然而然就會有工具利用它形成一個分享的生態圈，Vundle 及 Homebrew 就是經典的例子。

用 Vundle 安裝 vim plugin 時，只要簡單像下面加上一行 Plugin directive。

" .vimrc
Plugin "user/repo"

在 :PluginInstall 時就會去 GitHub 把 user/repo clone 在 .vim/bundle/user-repo 裡，再利用修改 vim runtimepath 的方法達到載入 plugin 的目的。

今天要介紹的 Homebrew Tap 2 也是利用 GitHub 來新增額外的 repo，用來分類與管理 formulae。

舉我剛剛建立的 Gasol/homebrew-formulae 為例：

首先在 GitHub 上建立好 repository，這邊要注意的是 repo 的名字一定要有 homebrew- 的前綴 3，否則 brew tap 會找不到。

shell> brew tap gasol/formulae

brew tap 會把 repo clone 在 /usr/local/Library/Taps/gasol/homebrew-formulae

shell> tree -CL 2 /usr/local/Library/Taps/
/usr/local/Library/Taps/
├── caskroom
│   └── homebrew-cask
├── gasol
│   └── homebrew-formulae
└── homebrew
├── homebrew-completions
├── homebrew-dupes
├── homebrew-php
└── homebrew-science

為了要 push formulae 上去 remote，所以我們要把 git 的 url 從 https 換成 ssh 的版本。

shell> cd /usr/local/Library/Taps/gasol/homebrew-formulae
shell /usr/local/Library/Taps/gasol/homebrew-formulae> git remote show origin
* remote origin
  Fetch URL: https://github.com/Gasol/homebrew-formulae.git
  Push  URL: https://github.com/Gasol/homebrew-formulae.git
  HEAD branch: master
  Remote branch:
    master tracked
  Local branch configured for 'git pull':
    master merges with remote master
  Local ref configured for 'git push':
    master pushes to master (up to date)

shell /usr/local/Library/Taps/gasol/homebrew-formulae> git remote set-url origin git@github.com:Gasol/homebrew-formulae.git
shell /usr/local/Library/Taps/gasol/homebrew-formulae> git remote show origin
* remote origin
  Fetch URL: git@github.com:Gasol/homebrew-formulae.git
  Push  URL: git@github.com:Gasol/homebrew-formulae.git
  HEAD branch: master
  Remote branch:
    master tracked
  Local branch configured for 'git pull':
    master merges with remote master
  Local ref configured for 'git push':
    master pushes to master (up to date)

之後就可以把自已建立的 formulae commit 進 repo 後再 push 上 GitHub。

shell /usr/local/Library/Taps/gasol/homebrew-formulae> git push -u origin master
Counting objects: 3, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 485 bytes | 0 bytes/s, done.
Total 3 (delta 0), reused 0 (delta 0)
To git@github.com:Gasol/homebrew-formulae.git
 * [new branch]      master -> master
Branch master set up to track remote branch master from origin.

舉凡官方不收或是有 license 疑慮的 formulae 變可透過 Homebrew Tap 的方式來自已管理。