


If you are managing a debian or ubuntu server, you may often use the dpkg or apt-get commands. These two commands are used to install, uninstall and update packages.
To check whether a specific package, such as firefox, is installed, use this command:
dpkg -s firefox
Sample output:
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}
As you can see above, firefox is already installed.
Similarly, you can use the dpkg-query command. This command will have a better output, of course, you can use wildcards.
dpkg-query -l firefox
Sample output:
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 mozilla
To list all packages installed on your system, enter the following command:
dpkg --get-selections
Sample output:
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
The above output may be very long, depending on the packages your system has installed.
You can also use grep to filter and cut more precise packages. For example, I want to use the dpkg command to view the gcc package installed in the system:
dpkg --get-selections | grep gcc
Sample output:
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
In addition, you can use the "-l" parameter to find out the location of the files in the package Location.
dpkg -l gcc-4.8
Example output:
/. /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
The above is the detailed content of How to check if a software package is installed in Linux. For more information, please follow other related articles on the PHP Chinese website!

Indispensable commands in Linux include: 1.ls: list directory contents; 2.cd: change working directory; 3.mkdir: create a new directory; 4.rm: delete file or directory; 5.cp: copy file or directory; 6.mv: move or rename file or directory. These commands help users manage files and systems efficiently by interacting with the kernel.

In Linux, file and directory management uses ls, cd, mkdir, rm, cp, mv commands, and permission management uses chmod, chown, and chgrp commands. 1. File and directory management commands such as ls-l list detailed information, mkdir-p recursively create directories. 2. Permission management commands such as chmod755file set file permissions, chownuserfile changes file owner, and chgrpgroupfile changes file group. These commands are based on file system structure and user and group systems, and operate and control through system calls and metadata.

MaintenanceModeinLinuxisaspecialbootenvironmentforcriticalsystemmaintenancetasks.Itallowsadministratorstoperformtaskslikeresettingpasswords,repairingfilesystems,andrecoveringfrombootfailuresinaminimalenvironment.ToenterMaintenanceMode,interrupttheboo

The core components of Linux include kernel, file system, shell, user and kernel space, device drivers, and performance optimization and best practices. 1) The kernel is the core of the system, managing hardware, memory and processes. 2) The file system organizes data and supports multiple types such as ext4, Btrfs and XFS. 3) Shell is the command center for users to interact with the system and supports scripting. 4) Separate user space from kernel space to ensure system stability. 5) The device driver connects the hardware to the operating system. 6) Performance optimization includes tuning system configuration and following best practices.

The five basic components of the Linux system are: 1. Kernel, 2. System library, 3. System utilities, 4. Graphical user interface, 5. Applications. The kernel manages hardware resources, the system library provides precompiled functions, system utilities are used for system management, the GUI provides visual interaction, and applications use these components to implement functions.

Linux maintenance mode can be entered through the GRUB menu. The specific steps are: 1) Select the kernel in the GRUB menu and press 'e' to edit, 2) Add 'single' or '1' at the end of the 'linux' line, 3) Press Ctrl X to start. Maintenance mode provides a secure environment for tasks such as system repair, password reset and system upgrade.

The steps to enter Linux recovery mode are: 1. Restart the system and press the specific key to enter the GRUB menu; 2. Select the option with (recoverymode); 3. Select the operation in the recovery mode menu, such as fsck or root. Recovery mode allows you to start the system in single-user mode, perform file system checks and repairs, edit configuration files, and other operations to help solve system problems.

The core components of Linux include the kernel, file system, shell and common tools. 1. The kernel manages hardware resources and provides basic services. 2. The file system organizes and stores data. 3. Shell is the interface for users to interact with the system. 4. Common tools help complete daily tasks.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Dreamweaver CS6
Visual web development tools

WebStorm Mac version
Useful JavaScript development tools

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

SublimeText3 Mac version
God-level code editing software (SublimeText3)