相信很多在做web开发、后台服务、api开发等IT朋友，都会接触到Linux、Ubuntu、Unix等系统的开发，如何在不卸载桌面的前提下开机能直接进入命令界面。
以Ubuntu16.04 为例（VM Ware 14版安装界面版）：
使用centos的朋友可以去官网进行下载资源。
下载地址：https://www.centos.org/download/
1、进入图形界面后，打开终端
输入：
$> vim /etc/inittab在默认的 run level 设置中,按照如下设置。id:5:initdefault:(默认的 run level 等级为 5,即图形界面)
将第一行的 5 修改为 3 即可。
# inittab is only used by upstart for the default runlevel. # # ADDING OTHER CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM. # # System initialization is started by /etc/init/rcS.conf # # Individual runlevels are started by /etc/init/rc.conf # # Ctrl-Alt-Delete is handled by /etc/init/control-alt-delete.conf # # Terminal gettys are handled by /etc/init/tty.conf and /etc/init/serial.conf, # with configuration in /etc/sysconfig/init. # # For information on how to write upstart event handlers, or how # upstart works, see init(5), init(8), and initctl(8). # # Default runlevel. The runlevels used are: # 0 - halt (Do NOT set initdefault to this) # 1 - Single user mode # 2 - Multiuser, without NFS (The same as 3, if you do not have networking) # 3 - Full multiuser mode # 4 - unused # 5 - X11 # 6 - reboot (Do NOT set initdefault to this) # id:3:initdefault:
2、重启系统即可进入
使用命令：
$> reboot
想使用Ubuntu的朋友可以去官网下载，地址：https://www.ubuntu.com/download
