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Chapter 5

Control files and their fields

The package management system manipulates data represented in a common format, known

as control data, stored in control files. Control files are used for source packages, binary packages

and the

.changes

files which control the installation of uploaded files

1

.

5.1 Syntax of control files

A control file consists of one or more paragraphs of fields

2

. The paragraphs are separated

by blank lines. Some control files allow only one paragraph; others allow several, in which

case each paragraph usually refers to a different package. (For example, in source packages,

the first paragraph refers to the source package, and later paragraphs refer to binary packages

generated from the source.)

Each paragraph consists of a series of data fields; each field consists of the field name, followed

by a colon and then the data/value associated with that field. It ends at the end of the line.

Horizontal whitespace (spaces and tabs) may occur immediately before or after the value and

is ignored there; it is conventional to put a single space after the colon. For example, a field

might be:

Package: libc6

the field name is

Package

and the field value

libc6

.

Some fields' values may span several lines; in this case each continuation line must start with

a space or a tab. Any trailing spaces or tabs at the end of individual lines of a field value are

ignored.

Except where otherwise stated, only a single line of data is allowed and whitespace is not sig 

nificant in a field body. Whitespace must not appear inside names (of packages, architectures,

files or anything else) or version numbers, or between the characters of multi character version

relationships.

1

dpkg

's internal databases are in a similar format.

2

The paragraphs are also sometimes referred to as stanzas.