rm -rf /usr/local/Cellar /usr/local/.git && brew cleanup
提示已安装，那么执行下面这个命令
daminge:test damingwuage$ rm -rf /usr/local/Cellar /usr/local/.git && brew cleanup
然后再执行damingwge:test damingwuage$ ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
==> This script will install:
/usr/local/bin/brew
/usr/local/Library/...
/usr/local/share/man/man1/brew.1
==> The following directories will be made group writable:
/usr/local/bin
/usr/local/Library
/usr/local/share
/usr/local/share/man
/usr/local/share/man/man1
/usr/local/share/doc
==> The following directories will have their group set to admin:
/usr/local/bin
/usr/local/Library
/usr/local/share
/usr/local/share/man
/usr/local/share/man/man1
/usr/local/share/doc
Press RETURN to continue or any other key to abort
==> /usr/bin/sudo /bin/chmod g+rwx /usr/local/bin /usr/local/Library /usr/local/share /usr/local/share/man /usr/local/share/man/man1 /usr/local/share/doc
Password:
==> /usr/bin/sudo /usr/bin/chgrp admin /usr/local/bin /usr/local/Library /usr/local/share /usr/local/share/man /usr/local/share/man/man1 /usr/local/share/doc
==> Downloading and installing Homebrew...
现在就显示正在安装brew
安装完成之后就可以输入执行下载软件
原文地址：http://blog.csdn.net/darongzi1314/article/details/46413779
