Ubuntu上的包管理系统使安装和删除包变得非常简单，但有时弄清楚您实际安装的特定包的版本非常重要。

apt-get实用程序只是debian dpkg实用程序的前端，它实际上完成了真正的工作。您可以使用此实用程序来确定安装的版本。

dpkg -s <packagename>

下面是一个示例，我试图找出在我的系统上安装了什么版本的Ruby：

geek@ubuntuServ:~$ dpkg -s ruby1.8

Package: ruby1.8 Status: install ok installed Priority: optional Section: interpreters Installed-Size: 272 Maintainer: Ubuntu Core Developers <[email protected]> Architecture: i386 Version: 1.8.4-5ubuntu1.2 Depends: libc6 (>= 2.4-1), libruby1.8 (>= 1.8.4) Suggests: ruby1.8-examples, rdoc1.8, ri1.8 Description: Interpreter of object-oriented scripting language Ruby 1.8 Ruby is the interpreted scripting language for quick and easy object-oriented programming. It has many features to process text files and to do system management tasks (as in perl). It is simple, straight-forward, and extensible. . This package provides version 1.8 series of Ruby. . On Debian, Ruby 1.8 is provided as separate packages. You can get full Ruby 1.8 distribution by installing following packages. . ruby1.8 ruby1.8-dev ri1.8 rdoc1.8 irb1.8 ruby1.8-elisp ruby1.8-examples libdbm-ruby1.8 libgdbm-ruby1.8 libtcltk-ruby1.8 libopenssl-ruby1.8 libreadline-ruby1.8 Original-Maintainer: akira yamada <[email protected]>

您可以看到我已经安装了1.8.4版本。