Chapter B. Binary packages (from old Packaging Manual)

109

postinst

,

preinst

,

postrm

,

prerm

These are executable files (usually scripts) which

dpkg

runs during installation, upgrade and removal of packages. They allow the package

to deal with matters which are particular to that package or require more complicated

processing than that provided by

dpkg

. Details of when and how they are called are in

`Package maintainer scripts and installation procedure' on page

39

.

It is very important to make these scripts idempotent. See `Maintainer scripts Idempo 

tency' on page

40

.

The maintainer scripts are guaranteed to run with a controlling terminal and can interact

with the user. See `Controlling terminal for maintainer scripts' on page

40

.

conffiles

This file contains a list of configuration files which are to be handled auto 

matically by

dpkg

(see `Configuration file handling (from old Packaging Manual)' on

page

121

). Note that not necessarily every configuration file should be listed here.

shlibs

This file contains a list of the shared libraries supplied by the package, with depen 

dency details for each. This is used by

dpkg shlibdeps

when it determines what de 

pendencies are required in a package control file. The

shlibs

file format is described on

`The

shlibs

File Format' on page

58

.

B.3 The main control information file:

control

The most important control information file used by

dpkg

when it installs a package is

control

. It contains all the package's  vital statistics .

The binary package control files of packages built from Debian sources are made by a special

tool,

dpkg gencontrol

, which reads

debian/control

and

debian/changelog

to find

the information it needs. See `Source packages (from old Packaging Manual)' on page

111

for

more details.

The fields in binary package control files are listed in `Binary package control files  

DEBIAN

/control

' on page

28

.

A description of the syntax of control files and the purpose of the fields is available in `Control

files and their fields' on page

27

.

B.4 Time Stamps

See `Time Stamps' on page

23

.