执行brew update后显示Permission denied

执行brew update后显示Permission denied

• 问题：
  执行与brew update相关的命令时会提示Permission denied
  执行brew update后显示如下：

touch: /usr/local/Homebrew/.git/FETCH_HEAD: Permission deniedtouch: /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/.git/FETCH_HEAD: Permission deniedfatal: Unable to create '/usr/local/Homebrew/.git/index.lock': Permission deniederror: could not lock config file .git/config: Permission denied

• 解决方法：
  先执行以下命令即可解决问题：

sudo chown -R $(whoami) /usr/local