Chapter 7. The Debian package management tools

42

We also provide a program called

start stop daemon

which is used to start daemons at

boot time or to stop daemons when the kernel runlevel is changed (e.g., from multi user to

single user or to halt). The same program is used by installation scripts when a new package

containing a daemon is installed, to stop running daemons, and restart them as necessary.

7.3 How can I tell what packages are already installed on a Debian

system?

To learn the status of all the packages installed on a Debian system, execute the command

dpkg   list

This prints out a one line summary for each package, giving a 2 letter status symbol (explained

in the header), the package name, the version which is installed, and a brief description.

To learn the status of packages whose names match the string any pattern beginning with  foo 

by executing the command:

dpkg   list 'foo*'

To get a more verbose report for a particular package, execute the command:

dpkg   status packagename

7.4 How can I find out what package produced a particular file?

To identify the package that produced the file named

foo

execute either:

dpkg   search filename

This searches for

filename

in installed packages.

(This is (currently) equivalent

to searching all of the files having the file extension of

.list

in the directory

/var/lib/dpkg/info/

, and adjusting the output to print the names of all the pack 

ages containing it, and diversions.)

A faster alternative to this is the

dlocate

tool.

zgrep foo Contents ARCH.gz

This searches for files which contain the substring

foo

in their full path names. The

files

Contents ARCH.gz

(where ARCH represents the wanted architecture) reside in

the major package directories (main, non free, contrib) at a Debian FTP site (i.e. un 

der

/debian/dists/sarge

). A

Contents

file refers only to the packages in the sub 

directory tree where it resides. Therefore, a user might have to search more than one

Contents

files to find the package containing the file

foo

.