近期在macos開發環境下使用npm，經常會出現無法mkdir，permission denied的問題，在windows下並沒有遇到這種情況。
經查詢需要在指令前使用sudo指令，例如：npm install your_module 改為 sudo npm install your_module
下方是一個報錯信息。
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是基於Linux的，所以本身sudo就是Linux下的指令，sudo命令以系統管理者的身份執行指令，依次，通過sudo所執行的指令就好像是root親自執行。