关于homebrew:brew-install每次都会Updating-Homebrew

办法 1：按住 control + c 勾销本次更新操作

➜  ~ brew install composer
Updating Homebrew...
^C

按住 control + c 之后命令行会显示 ^C，就代表曾经勾销了 Updating Homebrew 操作

大略不到 1 秒钟之后就会去执行咱们真正须要的安装操作了

➜  ~ brew install composer
Updating Homebrew...
^C==> Satisfying dependencies
==> Downloading https://getcomposer.org/download/1.7.2/composer.phar
...