Debian sudo自动补全

解决 debian sudo TAB 键不能自动补全命令的原因
一般情况，命令行输入 sudo apt-get ins 按 tab ，它后面会自动补全为 install 如果右面写了包的名的一部分，按 tab 它也会自动完成或列出候选的，这次parrotOS（基于debian）突然不好使了
首先确认是否安装了 自动补全的插件，输入
apt-get install bash-completion
然后在/etc/bash.bashrc ：
即 在 .bash_profile 里加
if [ -f /etc/bash_completion ]; then
. /etc/bash_completion
fi
就 ok 了
链接：http://gumelta.com/add-bash-completion-in-debian.php
完整 copy 下来吧：
Add Bash Completion In Debian
ash completion is a useful tool for completion of file paths, commands etc. By default it is enabled on Ubuntu but not on Debian. With two simple steps it can also be enabled on Debian.

1. Install bash-completion
   First of all we need the install the according package:
   apt-get install bash-completion
2. Add it to the bash profile
   Either edit the ~/.bash_profile file to enable it only for a given user or edit /etc/profile to add it system-wide. Add the following code:
   if [ -f /etc/bash_completion ]; then
   . /etc/bash_completion
   fi
3. Try it
   In order for it to work you have to log out and relogin and then you can make use of bash completion the usual way. E.g. issue:
   apt-g
   and then press the TAB key once and the command will be completed to apt-get. Or issue this:
   apt
   and then press TAB key twice. You can also try with
   apt-get install apa
   and then press TAB key once to complete as far as possible and a second time to list all options.