npm安装gyp报错 errno -13

mac本子，安装gyp报错

pangangdeMacBook-Pro:~ pangang$ npm -v
2.15.1
pangangdeMacBook-Pro:~ pangang$ npm install -g node-gyp
npm ERR! tar.unpack untar error /Users/pangang/.npm/node-gyp/3.4.0/package.tgz
npm ERR! Darwin 15.5.0
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "install" "-g" "node-gyp"
npm ERR! node v4.4.3
npm ERR! npm  v2.15.1
npm ERR! path /usr/local/lib/node_modules/node-gyp
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall mkdir

npm ERR! Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules/node-gyp'
npm ERR!     at Error (native)
npm ERR!  { [Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules/node-gyp']
npm ERR!   errno: -13,
npm ERR!   code: 'EACCES',
npm ERR!   syscall: 'mkdir',
npm ERR!   path: '/usr/local/lib/node_modules/node-gyp',
npm ERR!   fstream_type: 'Directory',
npm ERR!   fstream_path: '/usr/local/lib/node_modules/node-gyp',
npm ERR!   fstream_class: 'DirWriter',
npm ERR!   fstream_stack: 
npm ERR!    [ '/usr/local/lib/node_modules/npm/node_modules/fstream/lib/dir-writer.js:35:25',
npm ERR!      '/usr/local/lib/node_modules/npm/node_modules/mkdirp/index.js:47:53',
npm ERR!      'FSReqWrap.oncomplete (fs.js:82:15)' ] }
npm ERR! 
npm ERR! Please try running this command again as root/Administrator.

npm ERR! Please include the following file with any support request:
npm ERR!     /Users/pangang/npm-debug.log
pangangdeMacBook-Pro:~ pangang$ 

---

*nix 上的全局安装插件需要使用 sudo

sudo npm install -g node-gyp