npm源：npm install命令下載需要依賴包的服務器地址，默認是 npm ---- https://registry.npmjs.org/

而國外的源速度太慢，所以我們一般都用國內的淘寶源taobao - https://registry.npm.taobao.org/

我們可以通過nrm工具管理npm的源。

一：安裝nrm

npm  install   -g   nrm

二：查看nrm命令幫助文檔

nrm -h

 Usage: nrm [options] [command]
  Commands:
    ls                           List all the registries
    current                      Show current registry name
    use 
 
<registry>               Change registry to registry
    add <registry> <url> [home]  Add one custom registry
    del <registry>               Delete one custom registry
    home <registry> [browser]    Open the homepage of registry with optional browser
    test [registry]              Show response time 
 
for specific or all registries
    help                         Print this help
  Options:
    -h, --help     output usage information
    -V, --version  output the version number

三：常用命令：

1.nrm ls 查看已有的源

2.nrm add <源名稱> <源地址> //新增源

3.nrm use <源名稱>. //切換源

nrm管理npm源