在安装appium 或者升级npm的过程中会遇到这个问题。出错时的代码提示如下：
npm ERR! path /usr/local/lib/node_modules/npm/node_modules/cacache/node_modules/ssri npm ERR! code EACCES npm ERR! errno -13 npm ERR! syscall access npm ERR! Error: EACCES: permission denied, access '/usr/local/lib/node_modules/npm/node_modules/cacache/node_modules/ssri' npm ERR! { Error: EACCES: permission denied, access '/usr/local/lib/node_modules/npm/node_modules/cacache/node_modules/ssri' npm ERR! stack: 'Error: EACCES: permission denied, access \'/usr/local/lib/node_modules/npm/node_modules/cacache/node_modules/ssri\'', npm ERR! errno: -13, npm ERR! code: 'EACCES', npm ERR! syscall: 'access', npm ERR! path: '/usr/local/lib/node_modules/npm/node_modules/cacache/node_modules/ssri' } npm ERR! npm ERR! Please try running this command again as root/Administrator. npm ERR! A complete log of this run can be found in *************
解决方案：
sudo npm i -g npm