gem 安装软件出错While executing gem ..

sudo gem install cocoapods

的时候出现 While executing gem ... (Gem::FilePermissionError)
You don't have write permissions for the /usr/bin directory.

改为 sudo gem install -n /usr/local/bin cocoapods 即可

注：
安装其他软件以此类推

原文链接：https://blog.csdn.net/kangguang/article/details/79544515