启用 Tab 补全

1、安装 bash-completion 软件包

sudo apt install bash-completion

2、修改 /etc/bash.bashrc 文件（需要root权限，全局）或 ~/.bashrc 文件

/etc/bash.bashrc

# enable bash completion in interactive shells
# if ! shopt -oq posix; then
#   if [ -f /usr/share/bash-completion/bash_completion ]; then
#     . /usr/share/bash-completion/bash_completion
#   elif [ -f /etc/bash_completion ]; then
#     . /etc/bash_completion
#   fi
# fi
if ! shopt -oq posix; then 
  if [ -f /usr/share/bash-completion/bash_completion ]; then 
    . /usr/share/bash-completion/bash_completion 
  elif [ -f /etc/bash_completion ]; then 
    . /etc/bash_completion 
  fi 
fi 

~/.bashrc

# enable programmable completion features (you don't need to enable
# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
# if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
#     . /etc/bash_completion
# fi
if [ -f /etc/bash_completion ] && ! shopt -oq posix; then 
    . /etc/bash_completion 
fi 

3、最后 source 重载 /etc/bash.bashrc 文件或用户目录 .bashrc 文件

source /etc/bash.bashrc
source .bashrc