RPM package queries
This post is just a quick walk-through of some basic commands to help you find information about rpm
packages.
These commands will work for any rpm based distribution (Red Hat, Centos, Suse, Mageia).
Debian based distributions like Ubuntu or Mint use dpkg
instead of rpm
and I’ll cover those in a different post.
Query the rpm database
You can query the rpm
database to find a particular installed package using the -q
option.
With rpm -q
you must also pass a package name. For example, to find out what version of the httpd
server we have installed we can use rpm -q httpd
/
rpm -q httpd
httpd-2.4.6-45.el7.centos.4.x86_64
List all installed packages
To get a quick list of every installed package on an rpm
based Linux distribution you can use -qa
.
In this case you do not need to pass any specific package into the command. Often times you will use this to find a package when you are not sure of the exact name. For example, you might grep
for ruby
to find all the installed ruby
libraries.
Running rpm -qa | grep ruby
will produce output similar to this on a Centos 7 server.
rpm -qa | grep ruby
rubygem-json-1.7.7-29.el7.x86_64
ruby-libs-2.0.0.648-29.el7.x86_64
rubygems-2.0.14.1-29.el7.noarch
ruby-irb-2.0.0.648-29.el7.noarch
rubygem-bigdecimal-1.2.0-29.el7.x86_64
ruby-2.0.0.648-29.el7.x86_64
rubygem-rdoc-4.0.0-29.el7.noarch
rubygem-io-console-0.4.2-29.el7.x86_64
rubygem-psych-2.0.0-29.el7.x86_64
Find associated files
Using rpm -ql
and rpm -qc
will help you to locate files associated with a particular package.
This is a great tool to help you find your way around a newly installed application. For example, how could you find out that the configuration file for Apache can be found at /etc/httpd/conf/httpd.conf
, without searching the interwebs?
rpm -qc httpd
will list all of the configuration files.
rpm -qc httpd
/etc/httpd/conf.d/autoindex.conf
/etc/httpd/conf.d/userdir.conf
/etc/httpd/conf.d/welcome.conf
/etc/httpd/conf.modules.d/00-base.conf
/etc/httpd/conf.modules.d/00-dav.conf
/etc/httpd/conf.modules.d/00-lua.conf
/etc/httpd/conf.modules.d/00-mpm.conf
/etc/httpd/conf.modules.d/00-proxy.conf
/etc/httpd/conf.modules.d/00-systemd.conf
/etc/httpd/conf.modules.d/01-cgi.conf
/etc/httpd/conf/httpd.conf
/etc/httpd/conf/magic
/etc/logrotate.d/httpd
/etc/sysconfig/htcacheclean
/etc/sysconfig/httpd
Similarly running rpm -ql
will give you a list not only of configuration files but also every file that was installed on your server with its location.
Identify vendors
In some cases, you may need more information about a package. Who is the vendor? When was it installed? etc… Getting this type of information with rpm
packages is easy.
rpm -qi httpd
Name : httpd
Version : 2.4.6
Release : 45.el7.centos.4
Architecture: x86_64
Install Date: Mon 12 Jun 2017 09:37:04 PM UTC
Group : System Environment/Daemons
Size : 9823677
License : ASL 2.0
Signature : RSA/SHA256, Thu 13 Apr 2017 01:04:44 AM UTC, Key ID 24c6a8a7f4a80eb5
Source RPM : httpd-2.4.6-45.el7.centos.4.src.rpm
Build Date : Wed 12 Apr 2017 09:05:23 PM UTC
Build Host : c1bm.rdu2.centos.org
Relocations : (not relocatable)
Packager : CentOS BuildSystem <http://bugs.centos.org>
Vendor : CentOS
URL : http://httpd.apache.org/
Summary : Apache HTTP Server
Description :
The Apache HTTP Server is a powerful, efficient, and extensible
web server.
Finding documentation
You can also quickly find where documentation for a package can be found on your system using rpm -qd
.
rpm -qd httpd
/usr/share/doc/httpd-2.4.6/ABOUT_APACHE
/usr/share/doc/httpd-2.4.6/CHANGES
/usr/share/doc/httpd-2.4.6/LICENSE
/usr/share/doc/httpd-2.4.6/NOTICE
/usr/share/doc/httpd-2.4.6/README
/usr/share/doc/httpd-2.4.6/VERSIONING
/usr/share/doc/httpd-2.4.6/httpd-dav.conf
/usr/share/doc/httpd-2.4.6/httpd-default.conf
/usr/share/doc/httpd-2.4.6/httpd-info.conf
/usr/share/doc/httpd-2.4.6/httpd-languages.conf
/usr/share/doc/httpd-2.4.6/httpd-manual.conf
/usr/share/doc/httpd-2.4.6/httpd-mpm.conf
/usr/share/doc/httpd-2.4.6/httpd-multilang-errordoc.conf
/usr/share/doc/httpd-2.4.6/httpd-vhosts.conf
/usr/share/doc/httpd-2.4.6/proxy-html.conf
/usr/share/man/man8/apachectl.8.gz
/usr/share/man/man8/fcgistarter.8.gz
/usr/share/man/man8/htcacheclean.8.gz
/usr/share/man/man8/httpd.8.gz
/usr/share/man/man8/rotatelogs.8.gz
/usr/share/man/man8/suexec.8.gz
This documentation will include listing man
pages that might be available. As well as example configuration files. In this case you can see that /usr/share/doc/httpd-2.4.6/httpd-vhosts.conf
is an example of a virtual host file…. Maybe something that would come in handy as a template for virtual hosts you might have to set up.
As you can see there is quite a lot of information that can be extracted from the rpm database. In my humble opinion, this is one of the big advantages that rpm
has over dpkg
(though you can get this information from dpkg
, it’s just not as straight forward), rpm
makes it easy to query the database and quickly find the information you need.
All of this really only scratches the surface of what you can do as well. There are many ways to modify these commands to help you discover information about the packages you have installed on your system. I encourage you to read the full man
page for rpm
if you are interested in learning more in-depth capabilities for rpm
packages.