YUM (Yellowdog Updater, Modified) is a command-line package management utility for RPM-based Linux systems. It is used to install, update, remove, and manage software packages on the system. YUM automatically resolves dependencies between packages and can download and install packages from remote repositories. It is the default package manager for many popular Linux distributions such as CentOS, Fedora, and Red Hat Enterprise Linux.
Overview
YUM commands follow the syntax:
yum [options] [command] [package ...]
Here are some common YUM commands:
Install a package
To install a package, use the following command:
yum install package_name
For example, to install the Apache web server, run:
yum install httpd
Update a package
To update a package, use the following command:
yum update package_name
For example, to update the Apache web server, run:
yum update httpd
Remove a package
To remove a package, use the following command:
yum remove package_name
For example, to remove the Apache web server, run:
yum remove httpd
Search for a package
To search for a package, use the following command:
yum search package_name
For example, to search for the Apache web server, run:
yum search httpd
List installed packages
To list all installed packages, use the following command:
yum list installed
List available packages
To list all available packages in the configured repositories, use the following command:
yum list available
Options
Here are some commonly used options for the YUM command:
| Option | Description |
|---|---|
-y |
Automatically answer “yes” to all prompts |
--enablerepo=repo_name |
Enable a specific repository |
--disablerepo=repo_name |
Disable a specific repository |
--nogpgcheck |
Disable GPG signature checking |
--exclude=package_name |
Exclude a specific package from the command |
--skip-broken |
Skip packages with unresolved dependencies |
Troubleshooting tips
Here are some common issues that may occur when using YUM and how to troubleshoot them:
“No package available” error
If you receive a “No package available” error, it means that the package you are trying to install or update is not available in any of the configured repositories. You can try enabling additional repositories or downloading the package manually and installing it using the rpm command.
Dependency resolution errors
If YUM encounters dependency resolution errors, it means that the package you are trying to install or update requires other packages that are not available in any of the configured repositories. You can try enabling additional repositories or installing the missing packages manually.
GPG signature errors
If YUM encounters GPG signature errors, it means that the package you are trying to install or update is not signed with a trusted GPG key. You can try importing the GPG key manually using the rpm command or disabling GPG signature checking using the --nogpgcheck option.
Notes
- YUM uses a configuration file located at
/etc/yum.confto specify the repositories, proxy settings, and other options. - YUM can also be used with the
dnfcommand, which is a newer package manager that provides better performance and features. - YUM can be used to manage both binary and source packages, although source packages require additional configuration.