RPM packages typically have file names like foo-1.0-1.i386.rpm, which includes the package name (foo), version (1.0), release (1), and architecture (i386). Installing a package is as simple as:

# rpm -ivh foo-1.0-1.i386.rpm
foo                       ####################################
#

As you can see, RPM prints out the name of the package (which is not necessarily the same as the file name, which could have been 1.rpm), and then prints a succession of hash marks as the package is installed, as a sort of progress meter.

Installing packages is designed to be simple, but you can get a few errors:

If you attempt to install a package that contains a file that has already been installed by another package, you'll see:

# rpm -ivh foo-1.0-1.i386.rpm
foo           /usr/bin/foo conflicts with file from bar-1.0-1
error: foo-1.0-1.i386.rpm cannot be installed
#

To cause RPM to ignore that error, use --replacefiles on the command line:

# rpm -ivh --replacefiles foo-1.0-1.i386.rpm
foo                       ####################################
#

RPM packages can ``depend'' on other packages, which means that they require other packages to be installed in order to run properly. If you try to install a package for which there is such an unresolved dependency, you'll see:

# rpm -ivh bar-1.0-1.i386.rpm
failed dependencies:
        foo is needed by bar-1.0-1
#

To handle this error you should install the requested packages. If you want to force the installation anyway (a bad idea since the package probably will not run correctly), use --nodeps on the command line.

Uninstalling a package is just as simple as installing:

# rpm -e foo
#

Notice that we used the package name ``foo,'' not the name of the original package file
``foo-1.0-1.i386.rpm''.

You can encounter a dependency error when uninstalling a package if some other installed package depends on the one you are trying to remove. For example:

# rpm -e foo
removing these packages would break dependencies:
        foo is needed by bar-1.0-1
#

To cause RPM to ignore that error and uninstall the package anyway (which is also a bad idea since the package that depends on it will probably fail to work properly), use --nodeps on the command line.

Upgrading a package is almost just like installing.

# rpm -Uvh foo-2.0-1.i386.rpm
foo                       ####################################
#

What you don't see above is that RPM automatically uninstalled any old versions of the foo package. In fact you may want to always use -U to install packages, since it works fine even when there are no previous versions of the package installed.

This means that your changes to the configuration file may not be ``forward compatible'' with the new configuration file in the package, so RPM saved your original file, and installed a new one. You should investigate and resolve the differences between the two files as soon as possible to ensure that your system continues to function properly.

Since upgrading is really a combination of uninstalling and installing, you can encounter any errors from those modes, plus one more: If RPM thinks you are trying to upgrade to a package with an older version number, you will see:

# rpm -Uvh foo-1.0-1.i386.rpm
foo    package foo-2.0-1 (which is newer) is already installed
error: foo-1.0-1.i386.rpm cannot be installed
#

To cause RPM to ``upgrade'' anyway, use --oldpackage on the command line:

# rpm -Uvh --oldpackage foo-1.0-1.i386.rpm
foo                       ####################################
#

Freshening a package is similar to upgrading:

# rpm -Fvh foo-1.2-1.i386.rpm
foo                       ####################################
#

RPM's freshen option checks the versions of the packages specified on the command line against the versions of packages that have already been installed on your system. When a newer version of an already-installed package is processed by RPM's freshen option, it will be upgraded to the newer version. However, RPM's freshen option will not install a package if no previously-installed package of the same name exists. This differs from RPM's upgrade option, as an upgrade will install packages, whether or not an older version of the package was already installed.

RPM's freshen option works well with single packages or with a group of packages. It's especially handy if you've just downloaded a large number of different packages, and you only want to upgrade those packages that are already installed on your system. Using the freshen option means that you won't have to pick through the downloaded packages, deleting any unwanted ones before using RPM.

In this case, you can simply issue the following command:

# rpm -Fvh *.rpm

RPM will automatically upgrade only those packages that have already been installed.

Querying the database of installed packages is accomplished with rpm -q. A simple use is rpm -q foo which will print the package name, version, and release number of the installed package foo:

# rpm -q foo
foo-2.0-1
#

Instead of specifying the package name, you can use the following options with -q to specify what package(s) you want to query. These are called Package Specification Options.

• -a queries all currently installed packages.
• -f <file> will query the package owning <file>.
• -p <packagefile> queries the package <packagefile>.

There are a number of ways to specify what information to display about queried packages. The following options are used to select the information you are interested in. These are called Information Selection Options.

• -i displays package information such as name, description, release, size, build date, install date, vendor, and other miscellaneous information.
• -l displays the list of files that the package ``owns''.
• -s displays the state of all the files in the package.
• -d displays a list of files marked as documentation (man pages, info pages, README's, etc).
• -c displays a list of files marked as configuration files. These are the files you change after installation to adapt the package to your system (sendmail.cf, passwd, inittab, etc).

For those options that display file lists, you can add -v to your command line to get the lists in a familiar ls -l format.

Verifying a package compares information about files installed from a package with the same information from the original package. Among other things, verifying compares the size, MD5 sum, permissions, type, owner and group of each file.

rpm -V verifies a package. You can use any of the Package Selection Options listed for querying to specify the packages you wish to verify. A simple use is rpm -V foo which verifies that all the files in the foo package are as they were when they were originally installed. For example:

• To verify a package containing particular file:

  rpm -Vf /bin/vi
  

• To verify ALL installed packages:

  rpm -Va
  

• To verify an installed package against an RPM package file:

  rpm -Vp foo-1.0-1.i386.rpm
  

  This can be useful if you suspect that your RPM databases are corrupt.

If everything verified properly there will be no output. If there are any discrepancies they will be displayed. The format of the output is a string of 8 characters, a possible ``c'' denoting a configuration file, and then the file name. Each of the 8 characters denotes the result of a comparison of one attribute of the file to the value of that attribute recorded in the RPM database. A single ``.'' (period) means the test passed. The following characters denote failure of certain tests:

5

MD5 checksum

S

File size

L

Symbolic link

T

File modification time

D

Device

U

User

G

Group

M

Mode (includes permissions and file type)

If you see any output, use your best judgment to determine if you should remove or reinstall the package, or somehow fix the problem.