若是你正在管理Debian或者Ubuntu服务器，你也许会常用dpkg 或者 apt-get命令。这两个命令用来安装、卸载和更新包。html
在本篇中，让咱们看下如何在基于DEB的系统下检查是否安装了一个包。linux
要检查特定的包，好比firefox是否安装了，使用这个命令：c++
dpkg -s firefox
示例输出：web
Package: firefox Status: install ok installed Priority: optional
Section: web Installed-Size: 93339 Maintainer: Ubuntu Mozilla Team
ubuntu-mozillateam@lists.ubuntu.com Architecture: amd64 Version:
35.0+build3-0ubuntu0.14.04.2 Replaces: kubuntu-firefox-installer Provides: gnome-www-browser, iceweasel, www-browser Depends:
lsb-release, libasound2 (>= 1.0.16), libatk1.0-0 (>= 1.12.4), libc6
(>= 2.17), libcairo2 (>= 1.2.4), libdbus-1-3 (>= 1.0.2),
libdbus-glib-1-2 (>= 0.78), libfontconfig1 (>= 2.9.0), libfreetype6
(>= 2.2.1), libgcc1 (>= 1:4.1.1), libgdk-pixbuf2.0-0 (>= 2.22.0),
libglib2.0-0 (>= 2.37.3), libgtk2.0-0 (>= 2.24.0), libpango-1.0-0 (>=
1.22.0), libpangocairo-1.0-0 (>= 1.14.0), libstartup-notification0 (>= 0.8), libstdc++6 (>= 4.6), libx11-6, libxcomposite1 (>= 1:0.3-1), libxdamage1 (>= 1:1.1), libxext6, libxfixes3, libxrender1, libxt6
Recommends: xul-ext-ubufox, libcanberra0, libdbusmenu-glib4,
libdbusmenu-gtk4 Suggests: ttf-lyx Conffiles:
/etc/firefox/syspref.js 09e457e65435a1a043521f2bd19cd2a1
/etc/apport/blacklist.d/firefox ee63264f847e671832d42255912ce144
/etc/apport/native-origins.d/firefox 7c26b75c7c2b715c89cc6d85338252a4
/etc/apparmor.d/usr.bin.firefox f54f7a43361c7ecfa3874abca2f292cf
Description: Safe and easy web browser from Mozilla Firefox delivers
safe, easy web browsing. A familiar user interface, enhanced security
features including protection from online identity theft, and
integrated search let you get the most out of the web. Xul-Appid:
{ec8030f7-c20a-464f-9b0e-13a3a9e97384}ubuntu
如上所见，firefox已经安装了。bash
一样，你能够使用dpkg-query 命令。这个命令会有一个更好的输出，固然，你能够用通配符。服务器
dpkg-query -l firefox
示例输出：app
Desired=Unknown/Install/Remove/Purge/Hold |
Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name
Version Architecture Description
+++-====================================-=======================-=======================-============================================================================= ii firefox 35.0+build3-0ubuntu0.14 amd64
Safe and easy web browser from Mozillaide
要列出你系统中安装的全部包，输入下面的命令：svg
dpkg --get-selections
示例输出：
abiword install abiword-common
install accountsservice install acl
install adduser install alsa-base
install alsa-utils install anacron
install app-install-data install apparmor
install … zeitgeist install zeitgeist-core
install zeitgeist-datahub install zenity
install zenity-common install zip
install zlib1g:amd64 install zlib1g:i386
install
上面的输出可能会很是长，这依赖于你的系统已安装的包。
你一样能够经过grep来过滤割到更精确的包。好比，我想要使用dpkg命令查看系统中安装的gcc包：
dpkg --get-selections | grep gcc
示例输出：
gcc install gcc-4.8
install gcc-4.8-base:amd64 install gcc-4.8-base:i386
install gcc-4.9-base:amd64 install gcc-4.9-base:i386
install libgcc-4.8-dev:amd64 install libgcc1:amd64
install libgcc1:i386 install
此外，你能够使用“-L”参数来找出包中文件的位置。
dpkg -L gcc-4.8
示例输出：
/. /usr /usr/share /usr/share/doc /usr/share/doc/gcc-4.8-base
/usr/share/doc/gcc-4.8-base/README.Bugs
/usr/share/doc/gcc-4.8-base/NEWS.html
/usr/share/doc/gcc-4.8-base/quadmath
/usr/share/doc/gcc-4.8-base/quadmath/changelog.gz
/usr/share/doc/gcc-4.8-base/gcc …
/usr/bin/x86_64-linux-gnu-gcc-4.8 /usr/bin/x86_64-linux-gnu-gcc-ar-4.8
/usr/bin/x86_64-linux-gnu-gcov-4.8
就是这样了。但愿这篇对你有用。