Dpkg::Deps(3) libdpkg-perl Dpkg::Deps(3)
NAME
Dpkg::Deps - parse and manipulate dependencies of Debian packages
DESCRIPTION
The Dpkg::Deps module provides objects implementing various types of
dependencies.
The most important function is deps_parse(), it turns a dependency line
in a set of Dpkg::Deps::{Simple,AND,OR,Union} objects depending on the
case.
FUNCTIONS
All the deps_* functions are exported by default.
deps_eval_implication($rel_p, $v_p, $rel_q, $v_q)
($rel_p, $v_p) and ($rel_q, $v_q) express two dependencies as
(relation, version). The relation variable can have the following
values that are exported by Dpkg::Version: REL_EQ, REL_LT, REL_LE,
REL_GT, REL_GT.
This functions returns 1 if the "p" dependency implies the "q"
dependency. It returns 0 if the "p" dependency implies that "q" is
not satisfied. It returns undef when there's no implication.
The $v_p and $v_q parameter should be Dpkg::Version objects.
my $dep = deps_concat(@dep_list)
This function concatenates multiple dependency lines into a single
line, joining them with ", " if appropriate, and always returning a
valid string.
my $dep = deps_parse($line, %options)
This function parses the dependency line and returns an object,
either a Dpkg::Deps::AND or a Dpkg::Deps::Union. Various options
can alter the behaviour of that function.
use_arch (defaults to 1)
Take into account the architecture restriction part of the
dependencies. Set to 0 to completely ignore that information.
host_arch (defaults to the current architecture)
Define the host architecture. By default it uses
Dpkg::Arch::get_host_arch() to identify the proper
architecture.
build_arch (defaults to the current architecture)
Define the build architecture. By default it uses
Dpkg::Arch::get_build_arch() to identify the proper
architecture.
reduce_arch (defaults to 0)
If set to 1, ignore dependencies that do not concern the
current host architecture. This implicitely strips off the
architecture restriction list so that the resulting
dependencies are directly applicable to the current
architecture.
use_profiles (defaults to 1)
Take into account the profile restriction part of the
dependencies. Set to 0 to completely ignore that information.
build_profiles (defaults to no profile)
Define the active build profiles. By default no profile is
defined.
reduce_profiles (defaults to 0)
If set to 1, ignore dependencies that do not concern the
current build profile. This implicitly strips off the profile
restriction formula so that the resulting dependencies are
directly applicable to the current profiles.
reduce_restrictions (defaults to 0)
If set to 1, ignore dependencies that do not concern the
current set of restrictions. This implicitly strips off any
architecture restriction list or restriction formula so that
the resulting dependencies are directly applicable to the
current restriction. This currently implies "reduce_arch" and
"reduce_profiles", and overrides them if set.
union (defaults to 0)
If set to 1, returns a Dpkg::Deps::Union instead of a
Dpkg::Deps::AND. Use this when parsing non-dependency fields
like Conflicts.
build_dep (defaults to 0)
If set to 1, allow build-dep only arch qualifiers, that is
":native". This should be set whenever working with build-
deps.
my $bool = deps_iterate($deps, $callback_func)
This function visits all elements of the dependency object, calling
the callback function for each element.
The callback function is expected to return true when everything is
fine, or false if something went wrong, in which case the iteration
will stop.
Return the same value as the callback function.
deps_compare($a, $b)
Implements a comparison operator between two dependency objects.
This function is mainly used to implement the sort() method.
OBJECTS - Dpkg::Deps::*
There are several kind of dependencies. A Dpkg::Deps::Simple dependency
represents a single dependency statement (it relates to one package
only). Dpkg::Deps::Multiple dependencies are built on top of this
object and combine several dependencies in a different manners.
Dpkg::Deps::AND represents the logical "AND" between dependencies while
Dpkg::Deps::OR represents the logical "OR". Dpkg::Deps::Multiple
objects can contain Dpkg::Deps::Simple object as well as other
Dpkg::Deps::Multiple objects.
In practice, the code is only meant to handle the realistic cases
which, given Debian's dependencies structure, imply those restrictions:
AND can contain Simple or OR objects, OR can only contain Simple
objects.
Dpkg::Deps::KnownFacts is a special object that is used while
evaluating dependencies and while trying to simplify them. It
represents a set of installed packages along with the virtual packages
that they might provide.
COMMON FUNCTIONS
$dep->is_empty()
Returns true if the dependency is empty and doesn't contain any
useful information. This is true when a Dpkg::Deps::Simple object
has not yet been initialized or when a (descendant of)
Dpkg::Deps::Multiple contains an empty list of dependencies.
$dep->get_deps()
Returns a list of sub-dependencies. For Dpkg::Deps::Simple it
returns itself.
$dep->output([$fh])
"$dep"
Returns a string representing the dependency. If $fh is set, it
prints the string to the filehandle.
$dep->implies($other_dep)
Returns 1 when $dep implies $other_dep. Returns 0 when $dep implies
NOT($other_dep). Returns undef when there's no implication. $dep
and $other_dep do not need to be of the same type.
$dep->sort()
Sorts alphabetically the internal list of dependencies. It's a no-
op for Dpkg::Deps::Simple objects.
$dep->arch_is_concerned($arch)
Returns true if the dependency applies to the indicated
architecture. For multiple dependencies, it returns true if at
least one of the sub-dependencies apply to this architecture.
$dep->reduce_arch($arch)
Simplifies the dependency to contain only information relevant to
the given architecture. A Dpkg::Deps::Simple object can be left
empty after this operation. For Dpkg::Deps::Multiple objects, the
non-relevant sub-dependencies are simply removed.
This trims off the architecture restriction list of
Dpkg::Deps::Simple objects.
$dep->get_evaluation($facts)
Evaluates the dependency given a list of installed packages and a
list of virtual packages provided. Those lists are part of the
Dpkg::Deps::KnownFacts object given as parameters.
Returns 1 when it's true, 0 when it's false, undef when some
information is lacking to conclude.
$dep->simplify_deps($facts, @assumed_deps)
Simplifies the dependency as much as possible given the list of
facts (see object Dpkg::Deps::KnownFacts) and a list of other
dependencies that are known to be true.
$dep->has_arch_restriction()
For a simple dependency, returns the package name if the dependency
applies only to a subset of architectures. For multiple
dependencies, it returns the list of package names that have such a
restriction.
$dep->reset()
Clears any dependency information stored in $dep so that
$dep->is_empty() returns true.
Dpkg::Deps::Simple
Such an object has four interesting properties:
package
The package name (can be undef if the dependency has not been
initialized or if the simplification of the dependency lead to its
removal).
relation
The relational operator: "=", "<<", "<=", ">=" or ">>". It can be
undefined if the dependency had no version restriction. In that
case the following field is also undefined.
version
The version.
arches
The list of architectures where this dependency is applicable. It's
undefined when there's no restriction, otherwise it's an array ref.
It can contain an exclusion list, in that case each architecture is
prefixed with an exclamation mark.
archqual
The arch qualifier of the dependency (can be undef if there's
none). In the dependency "python:any (>= 2.6)", the arch qualifier
is "any".
METHODS
$simple_dep->parse_string('dpkg-dev (>= 1.14.8) [!hurd-i386]')
Parses the dependency and modifies internal properties to match the
parsed dependency.
$simple_dep->merge_union($other_dep)
Returns true if $simple_dep could be modified to represent the
union of both dependencies. Otherwise returns false.
Dpkg::Deps::Multiple
This is the base class for Dpkg::Deps::{AND,OR,Union}. It implements
the following methods:
$mul->add($dep)
Adds a new dependency object at the end of the list.
Dpkg::Deps::AND
This object represents a list of dependencies who must be met at the
same time.
$and->output([$fh])
The output method uses ", " to join the list of sub-dependencies.
Dpkg::Deps::OR
This object represents a list of dependencies of which only one must be
met for the dependency to be true.
$or->output([$fh])
The output method uses " | " to join the list of sub-dependencies.
Dpkg::Deps::Union
This object represents a list of relationships.
$union->output([$fh])
The output method uses ", " to join the list of relationships.
$union->implies($other_dep)
$union->get_evaluation($other_dep)
Those methods are not meaningful for this object and always return
undef.
$union->simplify_deps($facts)
The simplication is done to generate an union of all the
relationships. It uses $simple_dep->merge_union($other_dep) to get
its job done.
Dpkg::Deps::KnownFacts
This object represents a list of installed packages and a list of
virtual packages provided (by the set of installed packages).
my $facts = Dpkg::Deps::KnownFacts->new();
Creates a new object.
$facts->add_installed_package($package, $version, $arch, $multiarch)
Records that the given version of the package is installed. If
$version/$arch is undefined we know that the package is installed
but we don't know which version/architecture it is. $multiarch is
the Multi-Arch field of the package. If $multiarch is undef, it
will be equivalent to "Multi-Arch: no".
Note that $multiarch is only used if $arch is provided.
$facts->add_provided_package($virtual, $relation, $version, $by)
Records that the "$by" package provides the $virtual package.
$relation and $version correspond to the associated relation given
in the Provides field (if present).
my ($check, $param) = $facts->check_package($package)
$check is one when the package is found. For a real package, $param
contains the version. For a virtual package, $param contains an
array reference containing the list of packages that provide it
(each package is listed as [ $provider, $relation, $version ]).
This function is obsolete and should not be used.
Dpkg::Deps::KnownFacts is only meant to be filled with data and
then passed to Dpkg::Deps methods where appropriate, but it should
not be directly queried.
CHANGES
Version 1.05
New function: Dpkg::Deps::deps_iterate().
Version 1.04
New options: Add use_profiles, build_profiles, reduce_profiles and
reduce_restrictions to Dpkg::Deps::deps_parse().
New methods: Add $dep->profile_is_concerned() and
$dep->reduce_profiles() for all dependency objects.
Version 1.03
New option: Add build_arch option to Dpkg::Deps::deps_parse().
Version 1.02
New function: Dpkg::Deps::deps_concat()
Version 1.01
New method: Add $dep->reset() for all dependency objects.
New property: Dpkg::Deps::Simple now recognizes the arch qualifier
"any" and stores it in the "archqual" property when present.
New option: Dpkg::Deps::KnownFacts->add_installed_package() now accepts
2 supplementary parameters ($arch and $multiarch).
Deprecated method: Dpkg::Deps::KnownFacts->check_package() is obsolete,
it should not have been part of the public API.
Version 1.00
Mark the module as public.
1.17.27 2016-04-25 Dpkg::Deps(3)
Czas wygenerowania: 0.00030 sek.
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