The basic format of the rpm –q command follows:

rpm –q package_name

You need to provide the name of a package to query. For example:

rpm -q telnet-0.17

This command returns the name of the package, if installed. For example:

telnet-0.17-20

If the package is not installed, you’ll see a message like the following:

package telnet-0.17 is not installed

You can provide the whole package name to the rpm command, which includes the name, the version, and the RPM package number, as discussed in Chapter 3. You can also just provide the name and version number, as shown previously, or just the base name of the package.

For example, the following command uses just the base name of the package:

$ rpm -q telnet

telnet-0.17-20

Note

The rpm –q command expects a package name. Although it supports some amount of customized queries, you really need to know which packages you want the rpm command to report on.

You can provide more than one package name; the rpm command reports on each package, as shown following.

$ rpm -q telnet telnet-server

telnet-0.17-20

telnet-server-0.17-20

You need to change the way you query if you want to perform searches when you do not know the full package name in advance. The following sections cover options for creating various queries.

Up to now, we have used the rpm command to query only for specific packages. The –a option tells the rpm command to query for all packages. You can also use the longer option, --all, in place of –a.

For example:

rpm -qa

This command returns every package installed on your system, quite a few packages. The packages are returned one per line, as shown following.

words-2-17

kudzu-0.99.23-1

openldap-2.0.11-13

rpm-4.0.3-1.03

kernel-smp-2.4.7-10

quota-3.01pre9-3

expat-1.95.1-7

groff-perl-1.17.2-3

perl-DateManip-5.39-5

perl-libnet-1.0703-6

perl-URI-1.12-5

perl-XML-Parser-2.30-7

perl-XML-Twig-2.02-2

a2ps-4.13b-15

4Suite-0.11-2

XFree86-xfs-4.1.0-3

ghostscript-6.51-12

tcl-8.3.3-65

portmap-4.0-38

bind-utils-9.1.3-4

ftp-0.17-12

micq-0.4.6.p1-2

Note

This output has been modified to meet size constraints. Try the rpm –qa command to see the full output for your system.

There may be over a thousand packages on your system. Even so, the rpm –qa command executes surprisingly fast.

When you query all the installed packages, you get too much output for most purposes, other than to get a general idea of the magnitude of packages installed on your system. But if you cannot remember a package name, there's no real option, other than writing your own RPM query program.

You can take advantage of the power of the Linux shells, though, and the wonderful ability to pipe the output of one command into another to work around this problem. With the large amount of output, you may want to pipe the output to the more or less programs, and display the output one page at a time.

Cross Reference

For more information on the more or less commands, view the online manuals with the man more and man less commands.

Even with more and less, the rpm –qa command outputs too much information to be really useful, unless you can somehow filter the information automatically.

One of the common problems with package management comes when you want to track a given file on your system back to the package that “owns” the file (that is, the package that, when installed, installed the particular file).

The -qf option tells the rpm command to query for all packages that own a particular file. You can also use the longer option, --file, in place of –f. The basic syntax follows:

rpm -qf filename

For example, the grep command used in previous examples is really a file. (Just about all Linux commands are a file of some sort, be it a shell script or an executable application.) You can use a few Linux commands to determine which package provides this handy program.

First, we need the exact path to the file. For Linux commands, you can use the which command, if the program is in your path. (The grep program must be in your path, or commands with grep will fail.)

Try the following command:

which grep

This command returns the path to grep:

/bin/grep

We can now check which package owns this file with the following command:

# rpm -qf /bin/grep

grep-2.4.2-7

You can also use the Linux back-tick operator to perform this check with one command.

# rpm -qf `which grep`

grep-2.4.2-7

Production: note use of back-quote, `, above. Don’t change to “smart quotes” please. -Eric

If you use the bash shell, you can use the $(command parameters) syntax in place of the back tick, or `, characters. For example:

# rpm -qf $(which grep)

grep-2.4.2-7

If no package owns a given file, you’ll see output like the following:

# rpm -qf mail

file mail is not owned by any package

Often, the package that owns a file does not have an intuitive name. The ssh command, for example, is owned by the openssh-clients package, as shown following:

# rpm -qf `which ssh`

openssh-clients-3.1p1-2

As you can see, the name of a command does not always correspond directly to the name of the package that provides that command. This is where the rpm –qf command proves very useful. Otherwise, you would just have to know that OpenSSH is the project responsible for this command.

Symbolic Links

The rpm -qf command follows symbolic links. This was not always true with older versions of the rpm command, but the modern rpm command can now trace package ownership to files placed in linked directories.

For example, the directory /usr/lib/X11 is a link to the real directory, /usr/X11R6/lib/X11. You can track the package ownership of a file in that directory, XKeysymDB, for example, by using the following command:

# rpm -qf /usr/lib/X11/XKeysymDB

XFree86-4.2.0-72

This file, XKeysymDB, really resides in /usr/X11R6/lib/X11.