1、打开文件sudo vim /etc/bash.bashrc （root下操作）
2、找到下面几行 将它注释掉
if ! shopt -oq posix; then
if[ -f /usr/share/bash-completion/bash_completion];then
. /usr/share/bash-completion/bash_completion ];then
elif [ -f /etc/bash_completion];then
. /etc/bash_completion
fi
fi
3、保存退出
4、最后source /etc/bash.bashrc即可