近期在macos开发环境下使用npm，经常会出现无法mkdir，permission denied的问题，在windows下并没有遇到这种情况。
经查询需要在指令前使用sudo指令，例如：npm install your_module 改为 sudo npm install your_module
下方是一个报错信息。
npm ERR! path /Users/niceyoo/.npm/_cacache/index-v5/92/fc
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall mkdir
npm ERR! Error: EACCES: permission denied, mkdir '/Users/niceyoo/.npm/_cacache/index-v5/92/fc'
npm ERR! { [Error: EACCES: permission denied, mkdir '/Users/niceyoo/.npm/_cacache/index-v5/92/fc']
npm ERR! cause:
npm ERR! { Error: EACCES: permission denied, mkdir '/Users/niceyoo/.npm/_cacache/index-v5/92/fc'
npm ERR! errno: -13,
npm ERR! code: 'EACCES',
npm ERR! syscall: 'mkdir',
npm ERR! path: '/Users/niceyoo/.npm/_cacache/index-v5/92/fc' },
npm ERR! isOperational: true,
npm ERR! stack:
npm ERR! 'Error: EACCES: permission denied, mkdir \'/Users/niceyoo/.npm/_cacache/index-v5/92/fc\'',
npm ERR! errno: -13,
npm ERR! code: 'EACCES',
npm ERR! syscall: 'mkdir',
npm ERR! path: '/Users/niceyoo/.npm/_cacache/index-v5/92/fc' }
npm ERR!
npm ERR! The operation was rejected by your operating system.
npm ERR! It is likely you do not have the permissions to access this file as the current user
npm ERR!
npm ERR! If you believe this might be a permissions issue, please double-check the
npm ERR! permissions of the file and its containing directories, or try running
npm ERR! the command again as root/Administrator (though this is not recommended).
macos是基于Linux的，所以本身sudo就是Linux下的指令，sudo命令以系统管理者的身份执行指令，依次，通过sudo所执行的指令就好像是root亲自执行。
来源：oschina
链接：https://my.oschina.net/u/4335884/blog/3367991