参考：
1. http://www.commandlinefu.com/commands/view/1204/save-a-file-you-edited-in-vim-without-the-needed-permissions
2. http://www.cyberciti.biz/faq/vim-vi-text-editor-save-file-without-root-permission/2-2/
转载自： http://blog.csdn.net/liangliyin/article/details/6426187