在mac安装npm报错 ，因为我之前装过npm后来我卸掉了，在重装就不行了。

yikuair-MacBook-Pro:~ yikuair$ curl http://npmjs.org/install.sh | sh % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 85 0 85 0 0 17 0 --:--:-- 0:00:04 --:--:-- 275 sh: line 1: syntax error near unexpected token newline' sh: line 1: Moved: https://npmjs.org/install.sh'