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Apt-get man pages

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TIP Installing the same selection of packages several times. TIP Removing and installing at the same time. TIP apt --reinstall and aptitude reinstall. Installation of the unstable version of spamassassin. TIP apt-cache policy. Download the ebook. APT is a vast project, whose original plans included a graphical interface. It is based on a library which contains the core application, and apt-get is the first front end — command-line based — which was developed within the project.

Numerous other graphical interfaces then appeared as external projects: synaptic , aptitude which includes both a text mode interface and a graphical one — even if not complete yet , wajig , etc. The most recommended interface, apt , is the one that we will use in the examples given in this section. Note however that apt-get and aptitude have a very similar command line syntax. When there are major differences between apt , apt-get and aptitude , these differences will be detailed.

For any work with APT, the list of available packages needs to be updated; this can be done simply through apt update. Of course, installing from a CD-ROM set does not require any downloading — in this case, the operation is very fast. Installing and Removing. With APT, packages can be added or removed from the system, respectively with apt install package and apt remove package.

In both cases, APT will automatically install the necessary dependencies or delete the packages which depend on the package that is being removed. The apt purge package command involves a complete uninstallation — the configuration files are also deleted. It can be useful to systematically install the same list of packages on several computers.

This can be done quite easily. The pkg-list file then contains the list of installed packages. Next, transfer the pkg-list file onto the computers you want to update and use the following commands:. The first commands records the list of available packages in the dpkg database, then dpkg --set-selections restores the selection of packages that you wish to install, and the apt-get invocation executes the required operations!

It is possible to ask apt or apt-get , or aptitude to install certain packages and remove others on the same command line by adding a suffix. The next example shows two different ways to install package1 and to remove package2.

This can also be used to exclude packages which would otherwise be installed, for example due to a Recommends.

In general, the dependency solver will use that information as a hint to look for alternative solutions. The system can sometimes be damaged after the removal or modification of files in a package. The easiest way to retrieve these files is to reinstall the affected package.

Unfortunately, the packaging system finds that the latter is already installed and politely refuses to reinstall it; to avoid this, use the --reinstall option of the apt and apt-get commands. The following command reinstalls postfix even if it is already present:. The aptitude command line is slightly different, but achieves the same result with aptitude reinstall postfix. The problem does not arise with dpkg , but the administrator rarely uses it directly.

Be careful! Using apt --reinstall to restore packages modified during an attack will certainly not recover the system as it was. If the file sources. With this command, it is possible to go back to an older version of a package if for instance you know that it works well , provided that it is still available in one of the sources referenced by the sources.

Otherwise the snapshot. APT keeps a copy of each downloaded. In case of frequent updates, this directory can quickly take a lot of disk space with several versions of each package; you should regularly sort through them.

Two commands can be used: apt-get clean entirely empties the directory; apt-get autoclean only removes packages which can no longer be downloaded because they have disappeared from the Debian mirror and are therefore clearly useless the configuration parameter APT::Clean-Installed can prevent the removal of.

Note that apt does not support those commands. System Upgrade. Regular upgrades are recommended, because they include the latest security updates. To upgrade, use apt upgrade , apt-get upgrade or aptitude safe-upgrade of course after apt update.

This command looks for installed packages which can be upgraded without removing any packages. In other words, the goal is to ensure the least intrusive upgrade possible.

TIP Incremental upgrade. As we explained earlier, the aim of the apt update command is to download for each package source the corresponding Packages or Sources file.

However, even after a bzip2 compression, these files can remain rather large the Packages. If you wish to upgrade regularly, these downloads can take up a lot of time. To achieve this, official Debian mirrors distribute different files which list the differences between one version of the Packages file and the following version.

They are generated at each update of the archives and a history of one week is kept. For distributions like Stable and Testing , which change less, the gain is even more noticeable.

However, it can sometimes be of interest to force the download of the entire Packages file, especially when the last upgrade is very old and when the mechanism of incremental differences would not contribute much. This can also be interesting when network access is very fast but when the processor of the machine to upgrade is rather slow, since the time saved on the download is more than lost when the computer calculates the new versions of these files starting with the older versions and applying the downloaded differences.

To do that, you can use the configuration parameter Acquire::Pdiffs and set it to false. If you specified Testing or Unstable in your sources. To tell apt to use a specific distribution when searching for upgraded packages, you need to use the -t or --target-release option, followed by the name of the distribution you want for example: apt -t stable upgrade. For more important upgrades, such as the change from one major Debian version to the next, you need to use apt full-upgrade.

With this instruction, apt will complete the upgrade even if it has to remove some obsolete packages or install new dependencies. This is also the command used by users who work daily with the Debian Unstable release and follow its evolution day by day. It is so simple that it hardly needs explanation: APT's reputation is based on this great functionality.

Unlike apt and aptitude , apt-get doesn't know the full-upgrade command. Configuration Options. To discover more configuration options, read the apt. Directories with a. Each directory represents a configuration file which is split over multiple files. APT includes them in alphabetical order, so that the last ones can modify a configuration element defined in one of the first ones.

This structure brings some flexibility to the machine administrator and to the package maintainers. Indeed, the administrator can easily modify the configuration of the software by adding a ready-made file in the directory in question without having to change an existing file.

Package maintainers use the same approach when they need to adapt the configuration of another software to ensure that it perfectly co-exists with theirs. The Debian policy explicitly forbids modifying configuration files of other packages — only users are allowed to do this.

Remember that during a package upgrade, the user gets to choose the version of the configuration file that should be kept when a modification has been detected. Any external modification of the file would trigger that request, which would disturb the administrator, who is sure not to have changed anything.

Without a. Depending on the application, the. It is important to execute the script after any change in that directory so that the most recent modifications are taken into account. In the same way, it is important not to work directly in the configuration file created automatically, since everything would be lost at the next execution of the script. The chosen method. Managing Package Priorities. One of the most important aspects in the configuration of APT is the management of the priorities associated with each package source.

For instance, you might want to extend one distribution with one or two newer packages from Testing , Unstable or Experimental. It is possible to assign a priority to each available package the same package can have several priorities depending on its version or the distribution providing it.

APT defines several default priorities. APT will always install the highest priority package which follows this constraint. If two packages have the same priority, APT installs the newest one whose version number is the highest. If two packages of same version have the same priority but differ in their content, APT installs the version that is not installed this rule has been created to cover the case of a package update without the increment of the revision number, which is usually required.

If several generic entries exist, the first match is used. The available selection criteria include the package's name and the source providing it. Every package source is identified by the information contained in a Release file that APT downloads together with the Packages files.

It also gives the name of the distribution usually Stable , Testing , Unstable or Experimental for the standard distributions provided by Debian together with its version for example 8 for Debian Jessie. Let's have a look at its syntax through some realistic case studies of this mechanism. If you listed Experimental in your sources. This is of course a specific case, designed to keep users from installing Experimental packages by mistake.

Let's suppose that you only want to use packages from the stable version of Debian. Those provided in other versions should not be installed except if explicitly requested. You could use this entry:. Package: perl Pin: version 5.

How to use Linux Commands

Installing manpages-posix-dev package on Ubuntu Advanced Package Tool, or APT, is a free software user interface that works with core libraries to handle the installation and removal of software on Debian, Ubuntu and other Linux distributions. APT simplifies the process of managing software on Unix-like computer systems by automating the retrieval, configuration and installation of software packages, either from precompiled files or by compiling source code.

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Unless the -h , or --help option is given, one of the commands below must be present. A specific version of a package can be selected for installation by following the package name with an equals and the version of the package to select. This will cause that version to be located and selected for install. Alternatively a specific distribution can be selected by following the package name with a slash and the version of the distribution or the Archive name stable, testing, unstable. Both of the version selection mechanisms can downgrade packages and must be used with care.

apt (8) - Linux Man Pages

Advanced Package Tool , or APT , is a free-software user interface that works with core libraries to handle the installation and removal of software on Debian , Ubuntu , and related Linux distributions. APT is a collection of tools distributed in a package named apt. Three such programs are apt , apt-get and apt-cache. They are commonly used in examples of APT because they are simple and ubiquitous. The apt package is of " important " priority in all current Debian releases, and is therefore included in a default Debian installation. APT can be considered a front-end to dpkg , friendlier than the older dselect front-end. While dpkg performs actions on individual packages, APT manages relations especially dependencies between them, as well as sourcing and management of higher-level versioning decisions release tracking and version pinning. APT is often hailed as one of Debian's best features, [5] [6] [7] [8] which Debian developers attribute to the strict quality controls in Debian's policy. A major feature of APT is the way it calls dpkg — it does topological sorting of the list of packages to be installed or removed and calls dpkg in the best possible sequence. In some cases, it utilizes the --force options of dpkg.

apt-get(8) - Linux man page

All command line options can be set using the configuration file, the descriptions indicate the configuration option to set. For example, when using a Debian archive, this command retrieves and scans the Packages. An update should always be performed before an upgrade or dist-upgrade. Please be aware that the overall progress meter will be incorrect as the size of the package files cannot be known in advance. Packages currently installed with new versions available are retrieved and upgraded; under no circumstances are currently installed packages removed, or packages not already installed retrieved and installed.

TIP Installing the same selection of packages several times.

By using our site, you acknowledge that you have read and understand our Cookie Policy , Privacy Policy , and our Terms of Service. It only takes a minute to sign up. I have installed a minimal Debian 9 through CD image.

How to install manpages-posix-dev on Ubuntu 16.04 (Xenial Xerus)

I recently tutored a friend in C coding. Fortunately, there are some easy man pages that can be installed in Ubuntu that offer helpful information that I was able to use to help refresh my memory. These man pages are easily installed by installing the manpages-dev package.

By using our site, you acknowledge that you have read and understand our Cookie Policy , Privacy Policy , and our Terms of Service. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I just installed Windows Subsystem for Linux for the first time and downloaded the Debian distribution from the Windows Store. The first thing I tried to do was use the "mv" command. The second thing was to run "man mv" because I don't remember how to use it.

Accessing man pages on Ubuntu 16.04 LTS

One of the biggest changes that catches Windows users moving to Linux is the way that software is installed. Instead of downloading an executable file from some website or other, running it and hoping it doesn't clobber your existing library files DLLs or install some dubious adware or malware, Linux distributions maintain repositories of software, which are all packaged up for that distro and tested for compatibility with the rest of the distro. On this page of our guide to everything you need to know about Linux Commands, we will look at how this is done by distros that use the Advanced Packaging Tool apt software management system, as developed by Debian and used by distros from Ubuntu to Raspbian on the Raspberry Pi. A repository is a collection of software packages for a distro. Each major release of a distro will have its own repositories, and the packages will have been built for and tested with that release, but a repository is more than a collection of files. Each repo as they are usually called is indexed, making it easy to find what you want. It can also be quickly checked for updates for your package manager without any need to visit websites to check for updates, or the need for software to 'phone home' to check.

Install the manpages-dev and manpages-posix-dev (thanks ChristopheD) packages. You should be able to find them in synaptic, or type apt-get install  6 answers.

The suite also shares a common command line parser to provide a uniform environment. When an APT tool starts up it will read the configuration files in the following order:. Otherwise APT will print a notice that it has ignored a file, unless that file matches a pattern in the Dir::Ignore-Files-Silently configuration list - in which case it will be silently ignored. The configuration file is organized in a tree with options organized into functional groups. Options do not inherit from their parent groups.

man Pages for C Development in Ubuntu







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  2. Faetaur

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  3. Matilar

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