There are two handy tools to help you provide an additional information about system packages. The first tool is the package manager yum
and the second is yumdb
. Both tools display a different type of information. The other difference is that yumdb
command can be only used on packages currently installed on the system.
yum info
The yum
command can display an information about the package even if it is not currently installed. This is a handy way of querying additional information before the actual installation is performed. This can be done by using info
option. The following is a default output when using yum info
to query a package information. In the following example we will query some additional information about at
package:
# yum info at Loaded plugins: product-id, subscription-manager Available Packages Name : at Arch : x86_64 Version : 3.1.13 Release : 17.el7 Size : 50 k Repo : RHEL_7_Disc Summary : Job spooling tools URL : http://ftp.debian.org/debian/pool/main/a/at License : GPLv3+ and GPLv2+ and ISC and MIT and Public Domain Description : At and batch read commands from standard input or from a specified : file. At allows you to specify that a command will be run at a : particular time. Batch will execute commands when the system load : levels drop to a particular level. Both commands use user's shell. : : You should install the at package if you need a utility for : time-oriented job control. Note: If it is a recurring job that will : need to be repeated at the same time every day/week, etc. you should : use crontab instead.
yumdb info
The different set of information about any currently installed package can be retrieved by yumdb
command. The yumdb
command may be missing as it may not be installed on your system by default. To make the yumdb
command available you first need to install yum-utils
package.
[root@rhel7 ~]# yum install yum-utils
Once installed you can use yumdb
command to obtain additional information about any currently installed package. Once again we use at
package as an example. Below you can see a default output of yumdb info
command:
[root@rhel7 ~]# yumdb info at Loaded plugins: product-id at-3.1.13-17.el7.x86_64 checksum_data = 6257ddee132d91801cf303fe6f0660de6e8da64c2c132203ae54861f3667bdc3 checksum_type = sha256 command_line = install at from_repo = RHEL_7_Disc from_repo_revision = 1399448732 from_repo_timestamp = 1399448734 installed_by = 0 reason = user releasever = 7Server var_uuid = bd54f3b1-8d8c-4e79-9384-084d9a58d544