ls -Ssh /var/lib/apt/lists/partial | head
total 88G
46G security.ubuntu.com_ubuntu_dists_vivid-security_main_binary-amd64_Packages.bz2
42G us.archive.ubuntu.com_ubuntu_dists_vivid-updates_main_binary-i386_Packages.bz2
我尝试 bunzipping 并得到尾随垃圾：
bunzip2: us.archive.ubuntu.com_ubuntu_dists_vivid-updates_main_binary-i386_Packages.bz2: trailing garbage after EOF ignored
解压出来的文件看起来只有88K：
du -hs us.archive.ubuntu.com_ubuntu_dists_vivid-updates_main_binary-i386_Packages
88K
对文件末尾进行十六进制转储似乎会显示附加的目录列表：
tail -c 200 security.ubuntu.com_ubuntu_dists_vivid-security_main_binary-amd64_Packages.bz2 | hexdump -C
00000000 30 38 64 66 37 20 20 20 20 20 20 20 20 20 20 20 |08df7 |
00000010 20 20 34 38 31 39 20 75 6e 69 76 65 72 73 65 2f | 4819 universe/|
00000020 69 31 38 6e 2f 54 …