8.2. Working with Packages

Yum enables you to perform a complete set of operations with software packages, including searching for packages, viewing information about them, installing and removing.

8.2.1. Searching Packages

You can search all RPM package names, descriptions and summaries by using the following command:
yum search term
Replace term with a package name you want to search.

Example 8.4. Searching for packages matching a specific string

To list all packages that match vim, gvim, or emacs, type:
~]$ yum search vim gvim emacs
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
============================= N/S matched: vim ==============================
vim-X11.x86_64 : The VIM version of the vi editor for the X Window System
vim-common.x86_64 : The common files needed by any version of the VIM editor
[output truncated]

============================ N/S matched: emacs =============================
emacs.x86_64 : GNU Emacs text editor
emacs-auctex.noarch : Enhanced TeX modes for Emacs
[output truncated]

  Name and summary matches mostly, use "search all" for everything.
Warning: No matches found for: gvim
The yum search command is useful for searching for packages you do not know the name of, but for which you know a related term. Note that by default, yum search returns matches in package name and summary, which makes the search faster. Use the yum search all command for a more exhaustive but slower search.

Filtering the Results

All of yum's list commands allow you to filter the results by appending one or more glob expressions as arguments. Glob expressions are normal strings of characters which contain one or more of the wildcard characters * (which expands to match any character subset) and ? (which expands to match any single character).
Be careful to escape the glob expressions when passing them as arguments to a yum command, otherwise the Bash shell will interpret these expressions as pathname expansions, and potentially pass all files in the current directory that match the global expressions to yum. To make sure the glob expressions are passed to yum as intended, use one of the following methods:
  • escape the wildcard characters by preceding them with a backslash character
  • double-quote or single-quote the entire glob expression.
Examples in the following section demonstrate usage of both these methods.

8.2.2. Listing Packages

To list information on all installed and available packages type the following at a shell prompt:
yum list all
To list installed and available packages that match inserted glob expressions use the following command:
yum list glob_expression

Example 8.5. Listing ABRT-related packages

Packages with various ABRT add-ons and plug-ins either begin with abrt-addon-, or abrt-plugin-. To list these packages, type the following command at a shell prompt. Note how the wildcard characters are escaped with a backslash character:
~]$ yum list abrt-addon\* abrt-plugin\*
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Installed Packages
abrt-addon-ccpp.x86_64                   2.1.11-35.el7             @rhel-7-server-rpms
abrt-addon-kerneloops.x86_64             2.1.11-35.el7             @rhel-7-server-rpms
abrt-addon-pstoreoops.x86_64             2.1.11-35.el7             @rhel-7-server-rpms
abrt-addon-python.x86_64                 2.1.11-35.el7             @rhel-7-server-rpms
abrt-addon-vmcore.x86_64                 2.1.11-35.el7             @rhel-7-server-rpms
abrt-addon-xorg.x86_64                   2.1.11-35.el7             @rhel-7-server-rpms
To list all packages installed on your system use the installed keyword. The rightmost column in the output lists the repository from which the package was retrieved.
yum list installed glob_expression

Example 8.6. Listing all installed versions of the krb package

The following example shows how to list all installed packages that begin with krb followed by exactly one character and a hyphen. This is useful when you want to list all versions of certain component as these are distinguished by numbers. The entire glob expression is quoted to ensure proper processing.
~]$ yum list installed "krb?-*"
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Installed Packages
krb5-libs.x86_64                  1.13.2-10.el7                   @rhel-7-server-rpms
To list all packages in all enabled repositories that are available to install, use the command in the following form:
yum list available glob_expression

Example 8.7. Listing available gstreamer plug-ins

For instance, to list all available packages with names that contain gstreamer and then plugin, run the following command:
~]$ yum list available gstreamer\*plugin\*
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Available Packages
gstreamer-plugins-bad-free.i686             0.10.23-20.el7         rhel-7-server-rpms
gstreamer-plugins-base.i686                 0.10.36-10.el7         rhel-7-server-rpms
gstreamer-plugins-good.i686                 0.10.31-11.el7         rhel-7-server-rpms
gstreamer1-plugins-bad-free.i686            1.4.5-3.el7            rhel-7-server-rpms
gstreamer1-plugins-base.i686                1.4.5-2.el7            rhel-7-server-rpms
gstreamer1-plugins-base-devel.i686          1.4.5-2.el7            rhel-7-server-rpms
gstreamer1-plugins-base-devel.x86_64        1.4.5-2.el7            rhel-7-server-rpms
gstreamer1-plugins-good.i686                1.4.5-2.el7            rhel-7-server-rpms

Listing Repositories

To list the repository ID, name, and number of packages for each enabled repository on your system, use the following command:
yum repolist
To list more information about these repositories, add the -v option. With this option enabled, information including the file name, overall size, date of the last update, and base URL are displayed for each listed repository. As an alternative, you can use the repoinfo command that produces the same output.
yum repolist -v
yum repoinfo 
To list both enabled and disabled repositories use the following command. A status column is added to the output list to show which of the repositories are enabled.
yum repolist all
By passing disabled as a first argument, you can reduce the command output to disabled repositories. For further specification you can pass the ID or name of repositories or related glob_expressions as arguments. Note that if there is an exact match between the repository ID or name and the inserted argument, this repository is listed even if it does not pass the enabled or disabled filter.

8.2.3. Displaying Package Information

To display information about one or more packages, use the following command (glob expressions are valid here as well):
yum info package_name
Replace package_name with the name of the package.

Example 8.8. Displaying information on the abrt package

To display information about the abrt package, type:
~]$ yum info abrt
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Installed Packages
Name        : abrt
Arch        : x86_64
Version     : 2.1.11
Release     : 35.el7
Size        : 2.3 M
Repo        : installed
From repo   : rhel-7-server-rpms
Summary     : Automatic bug detection and reporting tool
URL         : https://fedorahosted.org/abrt/
License     : GPLv2+
Description : abrt is a tool to help users to detect defects in applications and
            : to create a bug report with all information needed by maintainer to fix
            : it. It uses plugin system to extend its functionality.
The yum info package_name command is similar to the rpm -q --info package_name command, but provides as additional information the name of the yum repository the RPM package was installed from (look for the From repo: line in the output).

Using yumdb

You can also query the yum database for alternative and useful information about a package by using the following command:
yumdb info package_name
This command provides additional information about a package, including the check sum of the package (and the algorithm used to produce it, such as SHA-256), the command given on the command line that was invoked to install the package (if any), and the reason why the package is installed on the system (where user indicates it was installed by the user, and dep means it was brought in as a dependency).

Example 8.9. Querying yumdb for information on the yum package

To display additional information about the yum package, type:
~]$ yumdb info yum
Loaded plugins: langpacks, product-id
yum-3.4.3-132.el7.noarch
     changed_by = 1000
     checksum_data = a9d0510e2ff0d04d04476c693c0313a11379053928efd29561f9a837b3d9eb02
     checksum_type = sha256
     command_line = upgrade
     from_repo = rhel-7-server-rpms
     from_repo_revision = 1449144806
     from_repo_timestamp = 1449144805
     installed_by = 4294967295
     origin_url = https://cdn.redhat.com/content/dist/rhel/server/7/7Server/x86_64/os/Packages/yum-3.4.3-132.el7.noarch.rpm
     reason = user
     releasever = 7Server
     var_uuid = 147a7d49-b60a-429f-8d8f-3edb6ce6f4a1
For more information on the yumdb command, see the yumdb(8) manual page.

8.2.4. Installing Packages

To install a single package and all of its non-installed dependencies, enter a command in the following form as root:
yum install package_name
You can also install multiple packages simultaneously by appending their names as arguments. To do so, type as root:
yum install package_name package_name
If you are installing packages on a multilib system, such as an AMD64 or Intel 64 machine, you can specify the architecture of the package (as long as it is available in an enabled repository) by appending .arch to the package name:
yum install package_name.arch

Example 8.10. Installing packages on multilib system

To install the sqlite package for the i686 architecture, type:
~]# yum install sqlite.i686
You can use glob expressions to quickly install multiple similarly named packages. Execute as root:
yum install glob_expression

Example 8.11. Installing all audacious plugins

Global expressions are useful when you want to install several packages with similar names. To install all audacious plug-ins, use the command in the following form:
~]# yum install audacious-plugins-\*
In addition to package names and glob expressions, you can also provide file names to yum install. If you know the name of the binary you want to install, but not its package name, you can give yum install the path name. As root, type:
yum install /usr/sbin/named
Yum then searches through its package lists, finds the package which provides /usr/sbin/named, if any, and prompts you as to whether you want to install it.
As you can see in the above examples, the yum install command does not require strictly defined arguments. It can process various formats of package names and glob expressions, which makes installation easier for users. On the other hand, it takes some time until yum parses the input correctly, especially if you specify a large number of packages. To optimize the package search, you can use the following commands to explicitly define how to parse the arguments:
yum install-n name
yum install-na name.architecture
yum install-nevra name-epoch:version-release.architecture
With install-n, yum interprets name as the exact name of the package. The install-na command tells yum that the subsequent argument contains the package name and architecture divided by the dot character. With install-nevra, yum will expect an argument in the form name-epoch:version-release.architecture. Similarly, you can use yum remove-n, yum remove-na, and yum remove-nevra when searching for packages to be removed.

Note

If you know you want to install the package that contains the named binary, but you do not know in which bin/ or sbin/ directory the file is installed, use the yum provides command with a glob expression:
~]# yum provides "*bin/named"
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-
              : manager
32:bind-9.9.4-14.el7.x86_64 : The Berkeley Internet Name Domain (BIND) DNS
                            : (Domain Name System) server
Repo        : rhel-7-server-rpms
Matched from:
Filename    : /usr/sbin/named
yum provides "*/file_name" is a useful way to find the packages that contain file_name.

Example 8.12. Installation Process

The following example provides an overview of installation with use of yum. To download and install the latest version of the httpd package, execute as root:
~]# yum install httpd
Loaded plugins: langpacks, product-id, subscription-manager
Resolving Dependencies
--> Running transaction check
---> Package httpd.x86_64 0:2.4.6-12.el7 will be updated
---> Package httpd.x86_64 0:2.4.6-13.el7 will be an update
--> Processing Dependency: 2.4.6-13.el7 for package: httpd-2.4.6-13.el7.x86_64
--> Running transaction check
---> Package httpd-tools.x86_64 0:2.4.6-12.el7 will be updated
---> Package httpd-tools.x86_64 0:2.4.6-13.el7 will be an update
--> Finished Dependency Resolution

Dependencies Resolved
After executing the above command, yum loads the necessary plug-ins and runs the transaction check. In this case, httpd is already installed. Since the installed package is older than the latest currently available version, it will be updated. The same applies to the httpd-tools package that httpd depends on. Then, a transaction summary is displayed:

================================================================================
 Package        Arch      Version                 Repository               Size
================================================================================
Updating:
 httpd          x86_64    2.4.6-13.el7            rhel-x86_64-server-7    1.2 M
Updating for dependencies:
 httpd-tools    x86_64    2.4.6-13.el7            rhel-x86_64-server-7     77 k

Transaction Summary
================================================================================
Upgrade  1 Package (+1 Dependent package)

Total size: 1.2 M
Is this ok [y/d/N]:
In this step yum prompts you to confirm the installation. Apart from y (yes) and N (no) options, you can choose d (download only) to download the packages but not to install them directly. If you choose y, the installation proceeds with the following messages until it is finished successfully.
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Updating   : httpd-tools-2.4.6-13.el7.x86_64                             1/4 
  Updating   : httpd-2.4.6-13.el7.x86_64                                   2/4 
  Cleanup    : httpd-2.4.6-12.el7.x86_64                                   3/4 
  Cleanup    : httpd-tools-2.4.6-12.el7.x86_64                             4/4 
  Verifying  : httpd-2.4.6-13.el7.x86_64                                   1/4 
  Verifying  : httpd-tools-2.4.6-13.el7.x86_64                             2/4 
  Verifying  : httpd-tools-2.4.6-12.el7.x86_64                             3/4 
  Verifying  : httpd-2.4.6-12.el7.x86_64                                   4/4 

Updated:
  httpd.x86_64 0:2.4.6-13.el7

Dependency Updated:
  httpd-tools.x86_64 0:2.4.6-13.el7

Complete!
To install a previously downloaded package from the local directory on your system, use the following command:
yum localinstall path
Replace path with the path to the package you want to install.

8.2.5. Downloading Packages

As shown in Example 8.12, “Installation Process”, at a certain point of installation process you are prompted to confirm the installation with the following message:
...
Total size: 1.2 M
Is this ok [y/d/N]:    
...
With the d option, yum downloads the packages without installing them immediately. You can install these packages later offline with the yum localinstall command or you can share them with a different device. Downloaded packages are saved in one of the subdirectories of the cache directory, by default /var/cache/yum/$basearch/$releasever/packages/. The downloading proceeds in background mode so that you can use yum for other operations in parallel.

8.2.6. Removing Packages

Similarly to package installation, yum enables you to uninstall them. To uninstall a particular package, as well as any packages that depend on it, run the following command as root:
yum remove package_name
As when you install multiple packages, you can remove several at once by adding more package names to the command.

Example 8.13. Removing several packages

To remove totem, type the following at a shell prompt:
~]# yum remove totem
Similar to install, remove can take these arguments:
  • package names
  • glob expressions
  • file lists
  • package provides

Warning

Yum is not able to remove a package without also removing packages which depend on it. This type of operation, which can only be performed by RPM, is not advised, and can potentially leave your system in a non-functioning state or cause applications to not work correctly or crash. For further information, see Section A.2.2, “Uninstalling Packages” in the RPM chapter.