deb822(5) dpkg suite deb822(5)NAMEdeb822 - Debian RFC822 control data format
DESCRIPTION
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 (dpkg's internal
databases are in a similar format).
SYNTAX
A control file consists of one or more paragraphs of fields (the
paragraphs are also sometimes referred to as stanzas). The paragraphs
are separated by empty lines. Parsers may accept lines consisting
solely of U+0020 SPACE and U+0009 TAB as paragraph separators, but
control files should use empty 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.) The
ordering of the paragraphs in control files is significant.
Each paragraph consists of a series of data fields. Each field
consists of the field name followed by a colon (U+003A ‘:’), and then
the data/value associated with that field. The field name is composed
of US-ASCII characters excluding control characters, space, and colon
(i.e., characters in the ranges U+0021 ‘!’ through U+0039 ‘9’, and
U+003B ‘;’ through U+007E ‘~’, inclusive). Field names must not begin
with the comment character (U+0023 ‘#’), nor with the hyphen character
(U+002D ‘-’).
The field ends at the end of the line or at the end of the last
continuation line (see below). Horizontal whitespace (U+0020 SPACE and
U+0009 TAB) 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: dpkg
the field name is Package and the field value dpkg.
Empty field values are only permitted in source package control files
(debian/control). Such fields are ignored.
A paragraph must not contain more than one instance of a particular
field name.
There are three types of fields:
simple The field, including its value, must be a single line. Folding
of the field is not permitted. This is the default field type
if the definition of the field does not specify a different
type.
folded The value of a folded field is a logical line that may span
several lines. The lines after the first are called
continuation lines and must start with a U+0020 SPACE or a
U+0009 TAB. Whitespace, including any newlines, is not
significant in the field values of folded fields.
This folding method is similar to RFC5322, allowing control
files that contain only one paragraph and no multiline fields to
be read by parsers written for RFC5322.
multiline
The value of a multiline field may comprise multiple
continuation lines. The first line of the value, the part on
the same line as the field name, often has special significance
or may have to be empty. Other lines are added following the
same syntax as the continuation lines of the folded fields.
Whitespace, including newlines, is significant in the values of
multiline fields.
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.
The presence and purpose of a field, and the syntax of its value may
differ between types of control files.
Field names are not case-sensitive, but it is usual to capitalize the
field names using mixed case as shown below. Field values are case-
sensitive unless the description of the field says otherwise.
Paragraph separators (empty lines) and lines consisting only of U+0020
SPACE and U+0009 TAB, are not allowed within field values or between
fields. Empty lines in field values are usually escaped by
representing them by a U+0020 SPACE followed by a dot (U+002E ‘.’).
Lines starting with U+0023 ‘#’, without any preceding whitespace are
comments lines that are only permitted in source package control files
(debian/control) and in deb-origin(5) files. These comment lines are
ignored, even between two continuation lines. They do not end logical
lines.
All control files must be encoded in UTF-8.
SEE ALSO
RFC822, RFC5322.
1.19.0.4 2017-11-02 deb822(5)
