技巧目录：

• 解决Ubuntu下每隔几分钟自动锁屏，需要重新输入密码的问题
• 无须输入用户名密码让Ubuntu自动登录到桌面
• Ubuntu下如何使用sudo不用输入密码

1. 解决Ubuntu下每隔几分钟自动锁屏，需要重新输入密码的问题

有时候几分钟不用Ubuntu，系统就自动锁屏了，这是一种安全措施，防止别人趁你不在时使用你的系统。但对于大部分人而言，这是没有必要的，尤其是Ubuntu虚拟机，里面没啥重要的东西，每次锁屏后需要重新输入密码解锁实际上非常枯燥且浪费时间。

解决方案：
（1）打开系统设置，找到“Brightness & Lock”（亮度和锁屏）设置并打开，如下图：

2. 无须输入用户名密码让Ubuntu自动登录到桌面

解决方案：
（1）系统设置里找到“User Accounts”

打开gdm.conf-custom，截取最前面的几句注释说明如下：

# GDM Configuration Customization file.
#
# This file is the appropriate place for specifying your customizations to the
# GDM configuration.   If you run gdmsetup, it will automatically edit this
# file for you and will cause the daemon and any running GDM GUI programs to
# automatically update with the new configuration.  Not all configuration
# options are supported by gdmsetup, so to modify some values it may be
# necessary to modify this file directly by hand.
#
# Older versions of GDM used the "gdm.conf" file for configuration.  If your
# system has an old gdm.conf file on the system, it will be used instead of
# this file - so changes made to this file will not take effect.  Consider
# migrating your configuration to this file and removing the gdm.conf file.

[daemon]
# Automatic login, if true the first attached screen will automatically logged
# in as user as set with AutomaticLogin key.
AutomaticLoginEnable=false
AutomaticLogin=

将“Enable Automatic Login“选上，然后选择你自己的用户名即可。

3. Ubuntu下如何使用sudo不用输入密码

# This file MUST be edited with the 'visudo' command as root.
#
# Please consider adding local content in /etc/sudoers.d/ instead of
# directly modifying this file.
#
# See the man page for details on how to write a sudoers file.
#
Defaults        env_reset
Defaults        mail_badpass
Defaults        secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"# Host alias specification# User alias specification# Cmnd alias specification# User privilege specification
root    ALL=(ALL:ALL) ALL# Members of the admin group may gain root privileges

默认情况我们会看到有"root    ALL=(ALL:ALL) ALL"这么一句话，意思就是root用户可以从任何主机连接进来以任意身份执行任意命令，但是需要输入密码，如果不想输入密码只要在后面的ALL之前加 上NOPASSWD即可，关于该文件的格式及参数详解请看参考文献或运行"man sudoers"看帮助文档吧。下面直接给出方法吧：