誤刪apt 來源查詢方法

cat /usr/share/doc/apt/examples/sources.list

結果:

# See sources.list(5) manpage for more information
# Remember that CD-ROMs, DVDs and such are managed through the apt-cdrom tool.
deb http://us.archive.ubuntu.com/ubuntu xenial main restricted
deb-src http://us.archive.ubuntu.com/ubuntu xenial main restricted

deb http://security.ubuntu.com/ubuntu xenial-security main restricted
deb-src http://security.ubuntu.com/ubuntu xenial-security main restricted

deb http://us.archive.ubuntu.com/ubuntu xenial-updates main restricted
deb-src http://us.archive.ubuntu.com/ubuntu xenial-updates main restricted