Chapter 6. Package maintainer scripts and installation procedure

44

6.6 Details of configuration

When we configure a package (this happens with

dpkg   install

and

dpkg

  configure

), we first update any

conffile

s and then call:

postinst

configure

most recently configured version

No attempt is made to unwind after errors during configuration.

If there is no most recently configured version

dpkg

will pass a null argument.

3

6.7 Details of removal and/or configuration purging

1

prerm

remove

2 The package's files are removed (except

conffile

s).

3

postrm

remove

4 All the maintainer scripts except the

postrm

are removed.

If we aren't purging the package we stop here. Note that packages which have no

postrm

and no

conffile

s are automatically purged when removed, as there is no dif 

ference except for the

dpkg

status.

5 The

conffile

s

and

any

backup

files

(

~

 files,

#*#

files,

%

 files,

.dpkg {old,new,tmp}

, etc.) are removed.

6

postrm

purge

7 The package's file list is removed.

If there are problems during this process, we call

postinst

abort remove

. No other attempt is made to unwind after errors during removal.

3

Historical note: Truly ancient (pre 1997) versions of

dpkg

passed

(including the angle brackets) in

this case. Even older ones did not pass a second argument at all, under any circumstance. Note that upgrades using

such an old dpkg version are unlikely to work for other reasons, even if this old argument behavior is handled by

your postinst script.