Chapter 6. Basics of the Debian package management system

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The Maintainer field gives the e mail address of the person who is currently responsible for

maintaining this package.

The Description field gives a brief summary of the package's features.

For more information about all possible fields a package can have, please see the Debian Policy

Manual, section 5.,  Control files and their fields .

6.5 What is a Debian conffile?

Conffiles is a list of configuration files (usually placed in

/etc

) that the package management

system will not overwrite when the package is upgraded. This ensures that local values for the

contents of these files will be preserved, and is a critical feature enabling the in place upgrade

of packages on a running system.

To determine exactly which files are preserved during an upgrade, run:

dpkg   status package

And look under  Conffiles: .

6.6 What is a Debian preinst, postinst, prerm, and postrm script?

These files are executable scripts which are automatically run before or after a package is in 

stalled. Along with a file named

control

, all of these files are part of the  control  section of

a Debian archive file.

The individual files are:

preinst This script executes before that package will be unpacked from its Debian archive

( .deb ) file. Many 'preinst' scripts stop services for packages which are being upgraded

until their installation or upgrade is completed (following the successful execution of the

'postinst' script).

postinst This script typically completes any required configuration of the package

foo

once

foo

has been unpacked from its Debian archive ( .deb ) file. Often, 'postinst' scripts

ask the user for input, and/or warn the user that if he accepts default values, he should

remember to go back and re configure that package as the situation warrants. Many

'postinst' scripts then execute any commands necessary to start or restart a service once

a new package has been installed or upgraded.

prerm This script typically stops any daemons which are associated with a package. It is

executed before the removal of files associated with the package.

postrm This script typically modifies links or other files associated with

foo

, and/or removes

files created by the package. (Also see `What is a Virtual Package?' on page

30

.)