找到git-completion bash文件
find / -name ‘git-completion‘
/usr/share/doc/git-1.7.1/contrib/completion/git-completion.bash
复制文件
cp /usr/share/doc/git-1.7.1/contrib/completion/git-completion.bash /etc/bash_completion.d/
source /etc/bash_completion.d/git-completion.bash