Ubuntu配置apacemacs：
下载emacs-25.3.tar.gz
tar zxf emacs-25.3.tar.gz
cd emacs-25.3
执行./configure命令出现如下错误：
'''shell
configure: error: You seem to be running X, but no X development libraries
were found. You should install the relevant development files for X
and for the toolkit you want, such as Gtk+, Lesstif or Motif. Also make
sure you have development files for image handling, i.e.
tiff, gif, jpeg, png and xpm.
If you are sure you want Emacs compiled without X window support, pass
--without-x
to configure.
'''
apt-cache search libgtk
apt-get install libgtk-3-dev
'''
configure: error: The following required libraries were not found:
libXpm libjpeg libgif/libungif libtiff
'''
apt-cache search libXpm
依次安装
Ubuntu配置共享文件夹
打开终端，切换到root权限，进入/mnt目录，执行命令：
新建目录：mkdir shared
挂载：sudo mount -t vboxsf share /mnt/shared/
查看：进入 /mnt/share/目录查看到了Windows下的文件。
ubuntu16.04忘记root密码
1、开机按ESC
选择advanced options for Ubuntu
2.回车
Ubuntu ,with Linux 4.4.0-24-generic (recovery mode)
3.等待加载完成..你将看到"Recovery Menu (filesystem state :read-only)"
4.选择root
Drop to root shell prompt 就会进入单用户模式了..
passwd
Enter new UNIX password:
Retype new UNIX password:
passwd: Authentication token manipulation error
passwd: password unchanged
mount -o rw,remount / .输入后什么也不会提示