若在提交.gitignore之前，不小心提交了无用的文件入repo，可以用以下命令在repo中去除这些文件
git
rm -r --cached <filename or .>
git add .
git commit -m
'.gitignore is now working'
源地址：http://stackoverflow.com/questions/1139762/ignore-files-that-have-already-been-committed-to-a-git-repository
转载于:https://www.cnblogs.com/maozhige/p/4029302.html
