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diff --git a/doc/source/library/apt_pkg.rst b/doc/source/library/apt_pkg.rst new file mode 100644 index 00000000..bcdf2f7a --- /dev/null +++ b/doc/source/library/apt_pkg.rst @@ -0,0 +1,2028 @@ +:mod:`apt_pkg` --- The low-level bindings for apt-pkg +===================================================== +.. module:: apt_pkg + +The apt_pkg extensions provides a more low-level way to work with apt. It can +do everything apt can, and is written in C++. It has been in python-apt since +the beginning. + +Module Initialization +--------------------- + +Initialization is needed for most functions, but not for all of them. Some can +be called without having run init*(), but will not return the expected value. + +.. function:: init_config + + Initialize the configuration of apt. This is needed for most operations. + +.. function:: init_system + + Initialize the system. + +.. function:: init + + A short cut to calling :func:`init_config` and :func:`init_system`. You + can use this if you do not use the command line parsing facilities provided + by :func:`parse_commandline`, otherwise call :func:`init_config`, parse + the commandline afterwards and finally call :func:`init_system`. + + +Working with the cache +---------------------- +.. class:: Cache([progress]) + + Return a :class:`Cache()` object. The optional parameter *progress* + specifies an instance of :class:`apt.progress.OpProgress()` which will + display the open progress. + + .. describe:: cache[pkgname] + + Return the :class:`Package()` object for the package name given by + *pkgname*. + + .. describe:: pkgname in cache + + Check whether a package with the name given by *pkgname* exists in + the cache. + + .. method:: update(progress, list[, pulse_interval]) + + Update the package cache. + + The parameter *progress* points to an :class:`apt.progress.FetchProgress()` + object. The parameter *list* refers to a :class:`SourceList()` object. + + The optional parameter *pulse_interval* describes the interval between + the calls to the :meth:`FetchProgress.pulse` method. + + .. attribute:: depends_count + + The total number of dependencies. + + .. attribute:: package_count + + The total number of packages available in the cache. + + .. attribute:: packages + + A sequence of :class:`Package` objects. + + .. attribute:: provides_count + + The number of provided packages. + + .. attribute:: ver_file_count + + .. todo:: Seems to be some mixture of versions and pkgFile. + + .. attribute:: version_count + + The total number of package versions available in the cache. + + .. attribute:: package_file_count + + The total number of Packages files available (the Packages files + listing the packages). This is the same as the length of the list in + the attribute :attr:`file_list`. + + .. attribute:: file_list + + A list of :class:`PackageFile` objects. + +.. class:: DepCache(cache) + + Return a :class:`DepCache` object. The parameter *cache* specifies an + instance of :class:`Cache`. + + The DepCache object contains various methods to manipulate the cache, + to install packages, to remove them, and much more. + + .. method:: commit(fprogress, iprogress) + + Apply all the changes made. + + The parameter *fprogress* has to be set to an instance of + apt.progress.FetchProgress or one of its subclasses. + + The parameter *iprogress* has to be set to an instance of + apt.progress.InstallProgress or one of its subclasses. + + .. method:: fix_broken() + + Try to fix all broken packages in the cache. + + .. method:: get_candidate_ver(pkg) + + Return the candidate version of the package, ie. the version that + would be installed normally. + + The parameter *pkg* refers to an :class:`Package` object, + available using the :class:`pkgCache`. + + This method returns a :class:`Version` object. + + .. method:: set_candidate_ver(pkg, version) + + The opposite of :meth:`pkgDepCache.get_candidate_ver`. Set the candidate + version of the :class:`Package` *pkg* to the :class:`Version` + *version*. + + .. method:: upgrade([dist_upgrade=False]) + + Perform an upgrade. More detailed, this marks all the upgradable + packages for upgrade. You still need to call + :meth:`pkgDepCache.commit` for the changes to apply. + + To perform a dist-upgrade, the optional parameter *dist_upgrade* has + to be set to True. + + .. method:: fix_broken() + + Fix broken packages. + + .. method:: read_pinfile() + + Read the policy, eg. /etc/apt/preferences. + + .. method:: minimize_upgrade() + + Go over the entire set of packages and try to keep each package marked + for upgrade. If a conflict is generated then the package is restored. + + .. todo:: + Explain better.. + + .. method:: mark_auto(pkg) + + Mark the :class:`Package` *pkg* as automatically installed. + + .. method:: mark_keep(pkg) + + Mark the :class:`Package` *pkg* for keep. + + .. method:: mark_delete(pkg[, purge]) + + Mark the :class:`Package` *pkg* for delete. If *purge* is True, + the configuration files will be removed as well. + + .. method:: mark_install(pkg[, auto_inst=True[, from_user=True]]) + + Mark the :class:`Package` *pkg* for install. + + If *auto_inst* is ``True``, the dependencies of the package will be + installed as well. This is the default. + + If *from_user* is ``True``, the package will be marked as manually + installed. This is the default. + + .. method:: set_reinstall(pkg) + + Set if the :class:`Package` *pkg* should be reinstalled. + + .. method:: is_upgradable(pkg) + + Return ``1`` if the package is upgradable. + + The package can be upgraded by calling :meth:`pkgDepCache.MarkInstall`. + + .. method:: is_now_broken(pkg) + + Return `1` if the package is broken now (including changes made, but + not committed). + + .. method:: is_inst_broken(pkg) + + Return ``1`` if the package is broken on the current install. This + takes changes which have not been committed not into effect. + + .. method:: is_garbage(pkg) + + Return ``1`` if the package is garbage, ie. if it is automatically + installed and no longer referenced by other packages. + + .. method:: is_auto_installed(pkg) + + Return ``1`` if the package is automatically installed (eg. as the + dependency of another package). + + .. method:: marked_install(pkg) + + Return ``1`` if the package is marked for install. + + .. method:: marked_upgrade(pkg) + + Return ``1`` if the package is marked for upgrade. + + .. method:: marked_delete(pkg) + + Return ``1`` if the package is marked for delete. + + .. method:: marked_keep(pkg) + + Return ``1`` if the package is marked for keep. + + .. method:: marked_reinstall(pkg) + + Return ``1`` if the package should be installed. + + .. method:: marked_downgrade(pkg) + + Return ``1`` if the package should be downgraded. + + .. attribute:: keep_count + + Integer, number of packages marked as keep + + .. attribute:: inst_count + + Integer, number of packages marked for installation. + + .. attribute:: del_count + + Number of packages which should be removed. + + .. attribute:: broken_count + + Number of packages which are broken. + + .. attribute:: usr_size + + The size required for the changes on the filesystem. If you install + packages, this is positive, if you remove them its negative. + + .. attribute:: deb_size + + The size of the packages which are needed for the changes to be + applied. + + .. attribute:: policy + + The underlying :class:`Policy` object used by the :class:`DepCache` to + select candidate versions. + + +.. class:: PackageManager(depcache) + + Return a new :class:`PackageManager` object. The parameter *depcache* + specifies a :class:`DepCache` object. + + :class:`PackageManager` objects provide several methods and attributes, + which will be listed here: + + .. method:: get_archives(fetcher, list, records) + + Add all the selected packages to the :class:`Acquire()` object + *fetcher*. + + The parameter *list* refers to a :class:`SourceList()` object. + + The parameter *records* refers to a :class:`PackageRecords()` object. + + .. method:: do_install() + + Install the packages. + + .. method:: fix_missing + + Fix the installation if a package could not be downloaded. + + .. attribute:: RESULT_COMPLETED + + A constant for checking whether the the result is 'completed'. + + Compare it against the return value of :meth:`PackageManager.get_archives` + or :meth:`PackageManager.do_install`. + + .. attribute:: RESULT_FAILED + + A constant for checking whether the the result is 'failed'. + + Compare it against the return value of :meth:`PackageManager.get_archives` + or :meth:`PackageManager.do_install`. + + .. attribute:: RESULT_INCOMPLETE + + A constant for checking whether the the result is 'incomplete'. + + Compare it against the return value of :meth:`PackageManager.get_archives` + or :meth:`PackageManager.do_install`. + +Improve performance with :class:`ActionGroup` +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +.. class:: ActionGroup(depcache) + + Create a new :class:`ActionGroup()` object for the :class:`DepCache` object + given by the parameter *depcache*. + + :class:`ActionGroup()` objects make operations on the cache faster by + delaying certain cleanup operations until the action group is released. + + ActionGroup is also a context manager and therefore supports the + :keyword:`with` statement. But because it becomes active as soon as it + is created, you should not create an ActionGroup() object before entering + the with statement. + + If you want to use ActionGroup as a with statement (which is recommended + because it makes it easier to see when an actiongroup is active), always + use the following form:: + + with apt_pkg.ActionGroup(depcache): + ... + + For code which has to run on Python versions prior to 2.5, you can also + use the traditional way:: + + actiongroup = apt_pkg.ActionGroup(depcache) + ... + actiongroup.release() + + :class:`ActionGroup` provides the following method: + + .. method:: release() + + Release the ActionGroup. This will reactive the collection of package + garbage. + +Resolving Dependencies +^^^^^^^^^^^^^^^^^^^^^^ + +.. class:: ProblemResolver(depcache) + + Return a new :class:`ProblemResolver` object. The parameter *depcache* + specifies a :class:`pDepCache` object. + + The problem resolver helps when there are problems in the package + selection. An example is a package which conflicts with another, already + installed package. + + .. method:: protect(pkg) + + Protect the :class:`Package()` object given by the parameter *pkg*. + + .. todo:: + + Really document it. + + .. method:: install_protect() + + Protect all installed packages from being removed. + + .. method:: remove(pkg) + + Remove the :class:`Package()` object given by the parameter *pkg*. + + .. todo:: + + Really document it. + + .. method:: clear(pkg) + + Reset the :class:`Package()` *pkg* to the default state. + + .. todo:: + + Really document it. + + .. method:: resolve() + + Try to resolve problems by installing and removing packages. + + .. method:: resolve_by_keep() + + Try to resolve problems only by using keep. + + +:class:`Package` +^^^^^^^^^^^^^^^^^ +.. class:: Package + + The pkgCache::Package objects are an interface to package specific + features. + + + Attributes: + + .. attribute:: current_ver + + The version currently installed, or None. This returns a + :class:`Version` object. + + .. attribute:: id + + The ID of the package. This can be used to store information about + the package. The ID is an int value. + + .. attribute:: name + + This is the name of the package. + + .. attribute:: provides_list + + A list of packages providing this package. More detailed, this is a + list of tuples (str:pkgname, ????, :class:`Version`). + + If you want to check for check for virtual packages, the expression + ``pkg.provides_list and not pkg._version_list`` helps you. It detects if + the package is provided by something else and is not available as a + real package. + + .. attribute:: rev_depends_list + + An iterator of :class:`Dependency` objects for dependencies on this + package. + + .. attribute:: section + + The section of the package, as specified in the record. The list of + possible sections is defined in the Policy. + + .. attribute:: version_list + + A list of :class:`Version` objects for all versions available in the + cache. + + **States**: + + .. attribute:: selected_state + + The state we want it to be, ie. if you mark a package for installation, + this is :attr:`apt_pkg.SELSTATE_INSTALL`. + + See :ref:`SelStates` for a list of available states. + + .. attribute:: inst_state + + The state the currently installed version is in. This is normally + :attr:`apt_pkg.INSTSTATE_OK`, unless the installation failed. + + See :ref:`InstStates` for a list of available states. + + .. attribute:: current_state + + The current state of the package (not installed, unpacked, installed, + etc). See :ref:`CurStates` for a list of available states. + + **Flags**: + + .. attribute:: auto + + Whether the package was installed automatically as a dependency of + another package. (or marked otherwise as automatically installed) + + .. attribute:: essential + + Whether the package is essential. + + .. attribute:: important + + Whether the package is important. + +Example: +~~~~~~~~~ +.. literalinclude:: ../examples/cache-packages.py + + + +:class:`Version` +^^^^^^^^^^^^^^^^^ +.. class:: Version + + The version object contains all information related to a specific package + version. + + .. attribute:: ver_str + + The version, as a string. + + .. attribute:: section + + The usual sections (eg. admin, net, etc.). Prefixed with the component + name for packages not in main (eg. non-free/admin). + + .. attribute:: arch + + The architecture of the package, eg. amd64 or all. + + .. attribute:: file_list + + A list of (:class:`PackageFile`, int: index) tuples for all Package + files containing this version of the package. + + .. attribute:: depends_list_str + + A dictionary of dependencies. The key specifies the type of the + dependency ('Depends', 'Recommends', etc.). + + The value is a list, containing items which refer to the or-groups of + dependencies. Each of these or-groups is itself a list, containing + tuples like ('pkgname', 'version', 'relation') for each or-choice. + + An example return value for a package with a 'Depends: python (>= 2.4)' + would be:: + + {'Depends': [ + [ + ('python', '2.4', '>=') + ] + ] + } + + The same for a dependency on A (>= 1) | B (>= 2):: + + {'Depends': [ + [ + ('A', '1', '>='), + ('B', '2', '>='), + ] + ] + } + + .. attribute:: depends_list + + This is basically the same as :attr:`Version.DependsListStr`, + but instead of the ('pkgname', 'version', 'relation') tuples, + it returns :class:`Dependency` objects, which can assist you with + useful functions. + + .. attribute:: parent_pkg + + The :class:`Package` object this version belongs to. + + .. attribute:: provides_list + + This returns a list of all packages provided by this version. Like + :attr:`Package.provides_list`, it returns a list of tuples + of the form ('virtualpkgname', ???, :class:`Version`), where as the + last item is the same as the object itself. + + .. attribute:: size + + The size of the .deb file, in bytes. + + .. attribute:: installed_size + + The size of the package (in kilobytes), when unpacked on the disk. + + .. attribute:: hash + + An integer hash value. + + .. attribute:: id + + An integer id. + + .. attribute:: priority + + The integer representation of the priority. This can be used to speed + up comparisons a lot, compared to :attr:`Version.priority_str`. + + The values are defined in the :mod:`apt_pkg` extension, see + :ref:`Priorities` for more information. + + .. attribute:: priority_str + + Return the priority of the package version, as a string, eg. + "optional". + + .. attribute:: downloadable + + Whether this package can be downloaded from a remote site. + + .. attribute:: translated_description + + Return a :class:`Description` object. + + +:class:`Dependency` +^^^^^^^^^^^^^^^^^^^^ +.. class:: Dependency + + Represent a dependency from one package to another one. + + .. method:: all_targets + + A list of :class:`Version` objects which satisfy the dependency, + and do not conflict with already installed ones. + + From my experience, if you use this method to select the target + version, it is the best to select the last item unless any of the + other candidates is already installed. This leads to results being + very close to the normal package installation. + + .. method:: smart_target_pkg + + Return a :class:`Version` object of a package which satisfies the + dependency and does not conflict with installed packages + (the 'natural target'). + + .. attribute:: target_ver + + The target version of the dependency, as string. Empty string if the + dependency is not versioned. + + .. attribute:: target_pkg + + The :class:`Package` object of the target package. + + .. attribute:: parent_ver + + The :class:`Version` object of the parent version, ie. the package + which declares the dependency. + + .. attribute:: parent_pkg + + The :class:`Package` object of the package which declares the + dependency. This is the same as using ParentVer.ParentPkg. + + .. attribute:: comp_type + + The type of comparison (>=, ==, >>, <=), as string. + + .. attribute:: dep_type + + The type of the dependency, as string, eg. "Depends". + + .. attribute:: dep_type_enum + + The type of the dependency, as an integer which can be compared to + one of the TYPE_* constants below. + + .. attribute:: dep_type_untranslated + + The type of the depndency, as an untranslated string. + + .. attribute:: id + + The ID of the package, as integer. + + .. attribute:: TYPE_CONFLICTS + + Constant for checking against dep_type_enum + + .. attribute:: TYPE_DEPENDS + + Constant for checking against dep_type_enum + + .. attribute:: TYPE_DPKG_BREAKS + + Constant for checking against dep_type_enum + + .. attribute:: TYPE_ENHANCES + + Constant for checking against dep_type_enum + + .. attribute:: TYPE_OBSOLETES + + Constant for checking against dep_type_enum + + .. attribute:: TYPE_PREDEPENDS + + Constant for checking against dep_type_enum + + .. attribute:: TYPE_RECOMMENDS + + Constant for checking against dep_type_enum + + .. attribute:: TYPE_REPLACES + + Constant for checking against dep_type_enum + + .. attribute:: TYPE_SUGGESTS + + Constant for checking against dep_type_enum + +Example: Find all missing dependencies +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +With the help of Dependency.AllTargets(), you can easily find all packages with +broken dependencies: + +.. literalinclude:: ../examples/missing-deps.py + + +:class:`Description` +^^^^^^^^^^^^^^^^^^^^^ +.. class:: Description + + Represent the description of the package. + + .. attribute:: language_code + + The language code of the description + + .. attribute:: md5 + + The md5 hashsum of the description + + .. attribute:: file_list + + A list of tuples (:class:`PackageFile`, int: index). + + + +Index Files +------------- + + +.. todo:: + + Complete them + +.. class:: MetaIndex + + .. attribute:: uri + .. attribute:: dist + .. attribute:: is_trusted + .. attribute:: index_files + + +.. class:: IndexFile + + .. method:: archive_uri(path) + + Return the full url to path in the archive. + + .. attribute:: label + + Return the Label. + + .. attribute:: describe + + A description of the :class:`IndexFile`. + + .. attribute:: exists + + Return whether the file exists. + + .. attribute:: has_packages + + Return whether the file has packages. + + .. attribute:: size + + Size of the file + + .. attribute:: is_trusted + + Whether we can trust the file. + + +.. class:: PackageFile + + A :class:`PackageFile` represents a Packages file, eg. + /var/lib/dpkg/status. + + .. attribute:: architecture + + The architecture of the package file. + + .. attribute:: archive + + The archive (eg. unstable) + + .. attribute:: component + + The component (eg. main) + + .. attribute:: filename + + The name of the file. + + .. attribute:: id + + The ID of the package. This is an integer which can be used to store + further information about the file [eg. as dictionary key]. + + .. attribute:: index_type + + The sort of the index file. In normal cases, this is + 'Debian Package Index'. + + .. attribute:: label + + The Label, as set in the Release file + + .. attribute:: not_automatic + + Whether packages from this list will be updated automatically. The + default for eg. example is 0 (aka false). + + .. attribute:: not_source + + Whether the file has no source from which it can be updated. In such a + case, the value is 1; else 0. /var/lib/dpkg/status is 0 for example. + + Example:: + + for pkgfile in cache.file_list: + if pkgfile.not_source: + print 'The file %s has no source.' % pkgfile.filename + + .. attribute:: origin + + The Origin, as set in the Release file + + .. attribute:: site + + The hostname of the site. + + .. attribute:: size + + The size of the file. + + .. attribute:: version + + The version, as set in the release file (eg. "4.0" for "Etch") + + + +The following example shows how to use PackageFile: + +.. literalinclude:: ../examples/cache-pkgfile.py + + +Records +-------- + +.. class:: PackageRecords(cache) + + Create a new :class:`PackageRecords` object, for the packages in the cache + specified by the parameter *cache*. + + Provide access to the packages records. This provides very useful + attributes for fast (convient) access to some fields of the record. + + .. method:: lookup(verfile_iter) + + Change the actual package to the package given by the verfile_iter. + + The parameter *verfile_iter* refers to a tuple consisting + of (:class:`PackageFile()`, int: index), as returned by various + attributes, including :attr:`Version.file_list`. + + Example (shortened):: + + cand = depcache.GetCandidateVer(cache['python-apt']) + records.Lookup(cand.FileList[0]) + # Now you can access the record + print records.SourcePkg # == python-apt + + .. attribute:: filename + + Return the field 'Filename' of the record. This is the path to the + package, relative to the base path of the archive. + + .. attribute:: md5_hash + + Return the MD5 hashsum of the package This refers to the field + 'MD5Sum' in the raw record. + + .. attribute:: sha1_hash + + Return the SHA1 hashsum of the package. This refers to the field 'SHA1' + in the raw record. + + .. attribute:: sha256_hash + + Return the SHA256 hashsum of the package. This refers to the field + 'SHA256' in the raw record. + + .. versionadded:: 0.7.9 + + .. attribute:: source_pkg + + Return the source package. + + .. attribute:: source_ver + + Return the source version. + + .. attribute:: maintainer + + Return the maintainer of the package. + + .. attribute:: short_desc + + Return the short description. This is the summary on the first line of + the 'Description' field. + + .. attribute:: long_desc + + Return the long description. These are lines 2-END from the + 'Description' field. + + .. attribute:: name + + Return the name of the package. This is the 'Package' field. + + .. attribute:: homepage + + Return the Homepage. This is the 'Homepage' field. + + .. attribute:: record + + Return the whole record as a string. If you want to access fields of + the record not available as an attribute, you can use + :class:`apt_pkg.TagSection` to parse the record and access the field + name. + + Example:: + + section = apt_pkg.TagSection(records.record) + print section['SHA256'] # Use records.sha256_hash instead + + +.. class:: SourceRecords + + This represents the entries in the Sources files, ie. the dsc files of + the source packages. + + .. note:: + + If the Lookup failed, because no package could be found, no error is + raised. Instead, the attributes listed below are simply not existing + anymore (same applies when no Lookup has been made, or when it has + been restarted). + + .. method:: lookup(pkgname) + + Lookup the record for the package named *pkgname*. To access all + available records, you need to call it multiple times. + + Imagine a package P with two versions X, Y. The first ``lookup(P)`` + would set the record to version X and the second ``lookup(P)`` to + version Y. + + .. method:: restart() + + Restart the lookup. + + Imagine a package P with two versions X, Y. The first ``Lookup(P)`` + would set the record to version X and the second ``Lookup(P)`` to + version Y. + + If you now call ``restart()``, the internal position will be cleared. + Now you can call ``lookup(P)`` again to move to X. + + .. attribute:: package + + The name of the source package. + + .. attribute:: version + + A string describing the version of the source package. + + .. attribute:: maintainer + + A string describing the name of the maintainer. + + .. attribute:: section + + A string describing the section. + + .. attribute:: record + + The whole record, as a string. You can use :func:`apt_pkg.ParseSection` + if you need to parse it. + + You need to parse the record if you want to access fields not available + via the attributes, eg. 'Standards-Version' + + .. attribute:: binaries + + Return a list of strings describing the package names of the binaries + created by the source package. This matches the 'Binary' field in the + raw record. + + .. attribute:: index + + The index in the Sources files. + + .. attribute:: files + + The list of files. This returns a list of tuples with the contents + ``(str: md5, int: size, str: path, str:type)``. + + .. attribute:: build_depends + + Return a dictionary representing the build-time dependencies of the + package. The format is the same as for :attr:`Version.depends_list_str` + and possible keys being ``"Build-Depends"``, ``"Build-Depends-Indep"``, + ``"Build-Conflicts"`` or ``"Build-Conflicts-Indep"``. + + +The Acquire interface +---------------------- +The Acquire Interface is responsible for all sorts of downloading in apt. All +packages, index files, etc. downloading is done using the Acquire functionality. + +The :mod:`apt_pkg` module provides a subset of this functionality which allows +you to implement file downloading in your applications. Together with the +:class:`PackageManager` class you can also fetch all the packages marked for +installation. + + +.. class:: Acquire([progress]) + + Return an :class:`Acquire` object. The parameter *progress* refers to + an :class:`apt.progress.FetchProgress()` object. + + Acquire objects maintaing a list of items which will be fetched or have + been fetched already during the lifetime of this object. To add new items + to this list, you can create new :class:`AcquireFile` objects which allow + you to add single files. + + Acquire items have multiple methods and attributes: + + .. method:: run() + + Fetch all the items which have been added by :class:`AcquireFile`. + + .. method:: shutdown() + + Shut the fetcher down. + + .. attribute:: total_needed + + The total amount of bytes needed (including those of files which are + already present) + + .. attribute:: fetch_needed + + The total amount of bytes which need to be fetched. + + .. attribute:: partial_present + + Whether some files have been acquired already. (???) + + .. attribute:: items + + A list of :class:`AcquireItem` objects which are attached to the + queue of this object. + + .. attribute:: workers + + A list of :class:`AcquireWorker` objects which are currently active + on this instance. + +.. class:: AcquireItem + + The :class:`AcquireItem()` objects represent the items of a + :class:`Acquire` object. :class:`AcquireItem()` objects can not be created + by the user, they are solely available through the :attr:`Acquire.items` + list of an :class:`Acquire` object. + + .. attribute:: id + + The ID of the item. + + .. attribute:: complete + + Is the item completely acquired? + + .. attribute:: local + + Is the item a local file? + + .. attribute:: mode + + A string indicating the current mode e.g. ``"Fetching"``. + + .. attribute:: is_trusted + + Can the file be trusted? + + .. attribute:: filesize + + The size of the file, in bytes. + + .. attribute:: error_text + + The error message. For example, when a file does not exist on a http + server, this will contain a 404 error message. + + .. attribute:: destfile + + The location the file is saved as. + + .. attribute:: desc_uri + + The source location. + + **Status**: + + .. attribute:: status + + Integer, representing the status of the item. + + .. attribute:: STAT_IDLE + + Constant for comparing :attr:`AcquireItem.status`. + + .. attribute:: STAT_FETCHING + + Constant for comparing :attr:`AcquireItem.status` + + .. attribute:: STAT_DONE + + Constant for comparing :attr:`AcquireItem.status` + + .. attribute:: STAT_ERROR + + Constant for comparing :attr:`AcquireItem.status` + + .. attribute:: STAT_AUTH_ERROR + + Constant for comparing :attr:`AcquireItem.status` + +.. class:: AcquireFile(owner, uri[, md5, size, descr, short_descr, destdir, destfile]) + + Create a new :class:`AcquireFile()` object and register it with *acquire*, + so it will be fetched. You must always keep around a reference to the + object, otherwise it will be removed from the Acquire queue again. + + The parameter *owner* refers to an :class:`Acquire()` object as returned + by :func:`GetAcquire`. The file will be added to the Acquire queue + automatically. + + The parameter *uri* refers to the location of the file, any protocol + of apt is supported. + + The parameter *md5* refers to the md5sum of the file. This can be used + for checking the file. + + The parameter *size* can be used to specify the size of the package, + which can then be used to calculate the progress and validate the download. + + The parameter *descr* is a descripition of the download. It may be + used to describe the item in the progress class. *short_descr* is the + short form of it. + + You can use *destdir* to manipulate the directory where the file will + be saved in. Instead of *destdir*, you can also specify the full path to + the file using the parameter *destfile*. You can not combine both. + + In terms of attributes, this class is a subclass of :class:`AcquireItem` + and thus inherits all its attributes. + +.. class:: AcquireWorker + + An :class:`AcquireWorker` object represents a subprocess responsible for + fetching files from remote locations. This class is not instanciable from + Python. + + .. attribute:: current_item + + The item which is currently being fetched. This returns an + :class:`AcquireItemDesc` object. + + .. attribute:: current_size + + How many bytes of the file have been downloaded. Zero if the current + progress of the file cannot be determined. + + .. attribute:: resumepoint + + The amount of the file that was already downloaded prior to starting + this worker. + + .. attribute:: status + + The most recent status string received from the subprocess. + + .. attribute:: total_size + + The total number of bytes to be downloaded. Zero if the total size is + unknown. + +.. class:: AcquireItemDesc + + An :class:`AcquireItemDesc` object stores information about the item which + can be used to describe the item. + + .. attribute:: description + + The long description given to the item. + + .. attribute:: owner + + The :class:`AcquireItem` object owning this object. + + .. attribute:: shortdesc + + A short description which has been given to this item. + + .. attribute:: uri + + The URI from which to download this item. + +.. class:: AcquireProgress + + A monitor object for downloads controlled by the Acquire class. This is + an mostly abstract class. You should subclass it and implement the + methods to get something useful. + + Methods defined here: + + .. method:: done(item: AcquireItemDesc) + + Invoked when an item is successfully and completely fetched. + + .. method:: fail(item: AcquireItemDesc) + + Invoked when the process of fetching an item encounters a fatal error. + + .. method:: fetch(item: AcquireItemDesc) + + Invoked when some of an item's data is fetched. + + .. method:: ims_hit(item: AcquireItemDesc) + + Invoked when an item is confirmed to be up-to-date. For instance, + when an HTTP download is informed that the file on the server was + not modified. + + .. method:: media_change(media: str, drive: str) -> bool + + Invoked when the user should be prompted to change the inserted + removable media. + + This method should not return until the user has confirmed to the user + interface that the media change is complete. + + The parameter *media* is the name of the media type that should be + changed, the parameter *drive* is the identifying name of the drive + whose media should be changed. + + Return True if the user confirms the media change, False if it is + cancelled. + + .. method:: pulse(owner: Acquire) -> bool + + Periodically invoked while the Acquire process is underway. + + Return False if the user asked to cancel the whole Acquire process. + + .. method:: start() + + Invoked when the Acquire process starts running. + + .. method:: stop() + + Invoked when the Acquire process stops running. + + There are also some data descriptors: + + .. attribute:: current_bytes + + The number of bytes fetched. + + .. attribute:: current_cps + + The current rate of download, in bytes per second. + + .. attribute:: current_items + + The number of items that have been successfully downloaded. + + .. attribute:: elapsed_time + + The amount of time that has elapsed since the download started. + + .. attribute:: fetched_bytes + + The total number of bytes accounted for by items that were + successfully fetched. + + .. attribute:: last_bytes + + The number of bytes fetched as of the previous call to pulse(), + including local items. + + .. attribute:: total_bytes + + The total number of bytes that need to be fetched. This member is + inaccurate, as new items might be enqueued while the download is + in progress! + + .. attribute:: total_items + + The total number of items that need to be fetched. This member is + inaccurate, as new items might be enqueued while the download is + in progress! + + +Hashes +------ +The apt_pkg module also provides several hash functions. If you develop +applications with python-apt it is often easier to use these functions instead +of the ones provides in Python's :mod:`hashlib` module. + +The module provides the two classes :class:`Hashes` and :class:`HashString` for +generic hash support: + +.. class:: Hashes(object) + + Calculate all supported hashes of the object. *object* may either be a + string, in which cases the hashes of the string are calculated, or a + :class:`file()` object or file descriptor, in which case the hashes of + its contents is calculated. The calculated hashes are then available via + attributes: + + .. attribute:: md5 + + The MD5 hash of the data, as string. + + .. attribute:: sha1 + + The SHA1 hash of the data, as string. + + .. attribute:: sha256 + + The SHA256 hash of the data, as string. + +.. class:: HashString(type: str, hash: str) + + HashString objects store the type of a hash and the corresponding hash. + They are used by e.g :meth:`IndexRecords.lookup`. The first parameter, + *type* refers to one of MD5Sum, SHA1 and SHA256. The second parameter + *hash* is the corresponding hash. + + .. describe:: str(hashstring) + + Convert the HashString to a string by joining the hash type and the + hash using ':', e.g. ``"MD5Sum:d41d8cd98f00b204e9800998ecf8427e"``. + + .. attribute:: hashtype + + The type of the hash. This may be MD5Sum, SHA1 or SHA256. + + .. method:: verify_file(filename: str) -> bool + + Verify that the file given by the parameter *filename* matches the hash + stored in this object. + +The :mod:`apt_pkg` module also provides the functions :func:`md5sum`, +:func:`sha1sum` and :func:`sha256sum` for creating a single hash from a +:class:`bytes` or :class:`file` object: + +.. function:: md5sum(object) + + Return the md5sum of the object. *object* may either be a string, in + which case the md5sum of the string is returned, or a :class:`file()` + object (or a file descriptor), in which case the md5sum of its contents is + returned. + + .. versionchanged:: 0.8.0 + Added support for using file descriptors. + +.. function:: sha1sum(object) + + Return the sha1sum of the object. *object* may either be a string, in + which case the sha1sum of the string is returned, or a :class:`file()` + object (or a file descriptor), in which case the sha1sum of its contents + is returned. + + .. versionchanged:: 0.8.0 + Added support for using file descriptors. + +.. function:: sha256sum(object) + + Return the sha256sum of the object. *object* may either be a string, in + which case the sha256sum of the string is returned, or a :class:`file()` + object (or a file descriptor), in which case the sha256sum of its contents + is returned. + + .. versionchanged:: 0.8.0 + Added support for using file descriptors. + +Debian control files +-------------------- +Debian control files are files containing multiple stanzas of :RFC:`822`-style +header sections. They are widely used in the Debian community, and can represent +many kinds of information. One example for such a file is the +:file:`/var/lib/dpkg/status` file which contains a list of the currently +installed packages. + +The :mod:`apt_pkg` module provides two classes to read those files and parts +thereof and provides a function :func:`RewriteSection` which takes a +:class:`TagSection()` object and sorting information and outputs a sorted +section as a string. + +.. class:: TagFile(file) + + An object which represents a typical debian control file. Can be used for + Packages, Sources, control, Release, etc. Such an object provides two + kinds of API which should not be used together: + + The first API implements the iterator protocol and should be used whenever + possible because it has less side effects than the other one. It may be + used e.g. with a for loop:: + + tagf = apt_pkg.TagFile(open('/var/lib/dpkg/status')) + for section in tagfile: + print section['Package'] + + .. method:: next() + + A TagFile is its own iterator. This method is part of the iterator + protocol and returns a :class:`TagSection` object for the next + section in the file. If there is no further section, this method + raises the :exc:`StopIteration` exception. + + From Python 3 on, this method is not available anymore, and the + global function ``next()`` replaces it. + + The second API uses a shared :class:`TagSection` object which is exposed + through the :attr:`section` attribute. This object is modified by calls + to :meth:`step` and :meth:`jump`. This API provides more control and may + use less memory, but is not recommended because it works by modifying + one object. It can be used like this:: + + tagf = apt_pkg.TagFile(open('/var/lib/dpkg/status')) + tagf.step() + print tagf.section['Package'] + + .. method:: step + + Step forward to the next section. This simply returns ``1`` if OK, and + ``0`` if there is no section. + + .. method:: offset + + Return the current offset (in bytes) from the beginning of the file. + + .. method:: jump(offset) + + Jump back/forward to *offset*. Use ``jump(0)`` to jump to the + beginning of the file again. + + .. attribute:: section + + This is the current :class:`TagSection()` instance. + +.. class:: TagSection(text) + + Represent a single section of a debian control file. + + .. describe:: section[key] + + Return the value of the field at *key*. If *key* is not available, + raise :exc:`KeyError`. + + .. describe:: key in section + + Return ``True`` if *section* has a key *key*, else ``False``. + + .. versionadded:: 0.8.0 + + .. method:: bytes + + The number of bytes in the section. + + .. method:: find(key, default='') + + Return the value of the field at the key *key* if available, + else return *default*. + + .. method:: find_flag(key) + + Find a yes/no value for the key *key*. An example for such a + field is 'Essential'. + + .. method:: get(key, default='') + + Return the value of the field at the key *key* if available, else + return *default*. + + .. method:: keys() + + Return a list of keys in the section. + +.. function:: rewrite_section(section: TagSection, order: list, rewrite_list: list) -> str + + Rewrite the section given by *section* using *rewrite_list*, and order the + fields according to *order*. + + The parameter *order* is a :class:`list` object containing the names of the + fields in the order they should appear in the rewritten section. + :data:`apt_pkg.REWRITE_PACKAGE_ORDER` and + :data:`apt_pkg.REWRITE_SOURCE_ORDER` are two predefined lists for rewriting + package and source sections, respectively. + + The parameter *rewrite_list* is a list of tuples of the form + ``(tag, newvalue[, renamed_to])``, whereas *tag* describes the field which + should be changed, *newvalue* the value which should be inserted or + ``None`` to delete the field, and the optional *renamed_to* can be used + to rename the field. + +.. data:: REWRITE_PACKAGE_ORDER + + The order in which the information for binary packages should be rewritten, + i.e. the order in which the fields should appear. + +.. data:: REWRITE_SOURCE_ORDER + + The order in which the information for source packages should be rewritten, + i.e. the order in which the fields should appear. + +Dependencies +------------ +.. function:: check_dep(pkgver, op, depver) + + Check that the dependency requirements consisting of op and depver can be + satisfied by the version pkgver. + + Example:: + + >>> bool(apt_pkg.check_dep("1.0", ">=", "1")) + True + +The following two functions provide the ability to parse dependencies. They +use the same format as :attr:`Version.depends_list_str`. + +.. function:: parse_depends(depends) + + Parse the string *depends* which contains dependency information as + specified in Debian Policy, Section 7.1. + + Returns a list. The members of this list are lists themselves and contain + one or more tuples in the format ``(package,version,operation)`` for every + 'or'-option given, e.g.:: + + >>> apt_pkg.parse_depends("PkgA (>= VerA) | PkgB (>= VerB)") + [[('PkgA', 'VerA', '>='), ('PkgB', 'VerB', '>=')]] + + + .. note:: + + The behavior of this function is different than the behavior of the + old function :func:`ParseDepends()`, because the third field + ``operation`` uses `>` instead of `>>` and `<` instead of `<<` which + is specified in control files. + + +.. function:: parse_src_depends(depends) + + Parse the string *depends* which contains dependency information as + specified in Debian Policy, Section 7.1. + + Returns a list. The members of this list are lists themselves and contain + one or more tuples in the format ``(package,version,operation)`` for every + 'or'-option given, e.g.:: + + >>> apt_pkg.parse_depends("PkgA (>= VerA) | PkgB (>= VerB)") + [[('PkgA', 'VerA', '>='), ('PkgB', 'VerB', '>=')]] + + + Furthemore, this function also supports to limit the architectures, as + used in e.g. Build-Depends:: + + >>> apt_pkg.parse_src_depends("a (>= 01) [i386 amd64]") + [[('a', '01', '>=')]] + + .. note:: + + The behavior of this function is different than the behavior of the + old function :func:`ParseDepends()`, because the third field + ``operation`` uses `>` instead of `>>` and `<` instead of `<<` which + is specified in control files. + + +Configuration +------------- + +.. class:: Configuration() + + Configuration() objects store the configuration of apt, mostly created + from the contents of :file:`/etc/apt.conf` and the files in + :file:`/etc/apt.conf.d`. + + .. describe:: key in conf + + Return ``True`` if *conf* has a key *key*, else ``False``. + + .. describe:: conf[key] + + Return the value of the option given key *key*. If it does not + exist, raise :exc:`KeyError`. + + .. describe:: conf[key] = value + + Set the option at *key* to *value*. + + .. method:: find(key[, default='']) + + Return the value for the given key *key*. This is the same as + :meth:`Configuration.get`. + + If *key* does not exist, return *default*. + + .. method:: find_file(key[, default='']) + + Return the filename hold by the configuration at *key*. This formats the + filename correctly and supports the Dir:: stuff in the configuration. + + If *key* does not exist, return *default*. + + .. method:: find_dir(key[, default='/']) + + Return the absolute path to the directory specified in *key*. A + trailing slash is appended. + + If *key* does not exist, return *default*. + + .. method:: find_i(key[, default=0]) + + Return the integer value stored at *key*. + + If *key* does not exist, return *default*. + + .. method:: find_b(key[, default=0]) + + Return the boolean value stored at *key*. This returns an integer, but + it should be treated like True/False. + + If *key* does not exist, return *default*. + + .. method:: set(key, value) + + Set the value of *key* to *value*. + + .. method:: exists(key) + + Check whether the key *key* exists in the configuration. + + .. method:: subtree(key) + + Return a sub tree starting at *key*. The resulting object can be used + like this one. + + .. method:: list([key]) + + List all items at *key*. Normally, return the keys at the top level, + eg. APT, Dir, etc. + + Use *key* to specify a key of which the childs will be returned. + + .. method:: value_list([key]) + + Same as :meth:`Configuration.list`, but this time for the values. + + .. method:: my_tag() + + Return the tag name of the current tree. Normally this is an empty + string, but for subtrees it is the key of the subtree. + + .. method:: clear(key) + + Clear the configuration. Remove all values and keys at *key*. + + .. method:: keys([key]) + + Return all the keys, recursive. If *key* is specified, ... (FIXME) + + .. method:: get(key[, default='']) + + This behaves just like :meth:`dict.get` and :meth:`Configuration.find`, + it returns the value of key or if it does not exist, *default*. + +.. data:: config + + A :class:`Configuration()` object with the default configuration. This + object is initialized by calling :func:`init_config`. + + +.. function:: read_config_file(configuration, filename) + + Read the configuration file specified by the parameter *filename* and add + the settings therein to the :class:`Configuration()` object specified by + the parameter *configuration* + +.. function:: read_config_dir(configuration, dirname) + + Read configuration files in the directory specified by the parameter + *dirname* and add the settings therein to the :class:`Configuration()` + object specified by the parameter *configuration*. + +.. function:: read_config_file_isc(configuration, filename) + + Read the configuration file specified by the parameter *filename* and add + the settings therein to the :class:`Configuration()` object specified by + the parameter *configuration* + +.. function:: parse_commandline(configuration, options, argv) + + This function is like getopt except it manipulates a configuration space. + output is a list of non-option arguments (filenames, etc). *options* is a + list of tuples of the form ``('c',"long-opt or None", + "Configuration::Variable","optional type")``. + + Where ``type`` may be one of HasArg, IntLevel, Boolean, InvBoolean, + ConfigFile, or ArbItem. The default is Boolean. + +Locking +-------- +When working on the global cache, it is important to lock the cache so other +programs do not modify it. This module provides two context managers for +locking the package system or file-based locking. + +.. class:: SystemLock + + Context manager for locking the package system. The lock is established + as soon as the method __enter__() is called. It is released when + __exit__() is called. If the lock can not be acquired or can not be + released an exception is raised. + + This should be used via the 'with' statement, e.g.:: + + with apt_pkg.SystemLock(): + ... # Do your stuff here. + ... # Now it's unlocked again + + Once the block is left, the lock is released automatically. The object + can be used multiple times:: + + lock = apt_pkg.SystemLock() + with lock: + ... + with lock: + ... + +.. class:: FileLock(filename: str) + + Context manager for locking using a file. The lock is established + as soon as the method __enter__() is called. It is released when + __exit__() is called. If the lock can not be acquired or can not be + released, an exception is raised. + + This should be used via the 'with' statement, e.g.:: + + with apt_pkg.FileLock(filename): + ... + + Once the block is left, the lock is released automatically. The object + can be used multiple times:: + + lock = apt_pkg.FileLock(filename) + with lock: + ... + with lock: + ... + +For Python versions prior to 2.5, similar functionality is provided by the +following three functions: + +.. function:: get_lock(filename, errors=False) -> int + + Create an empty file at the path specified by the parameter *filename* and + lock it. If this fails and *errors* is **True**, the function raises an + error. If *errors* is **False**, the function returns -1. + + The lock can be acquired multiple times within the same process, and can be + released by calling :func:`os.close` on the return value which is the file + descriptor of the created file. + +.. function:: pkgsystem_lock() + + Lock the global pkgsystem. The lock should be released by calling + :func:`pkgsystem_unlock` again. If this function is called n-times, the + :func:`pkgsystem_unlock` function must be called n-times as well to release + all acquired locks. + +.. function:: pkgsystem_unlock() + + Unlock the global pkgsystem. This reverts the effect of + :func:`pkgsystem_unlock`. + + +Other classes +-------------- +.. class:: Cdrom() + + Return a Cdrom object with the following methods: + + .. method:: ident(progress) + + Identify the cdrom. The parameter *progress* refers to an + :class:`apt.progress.CdromProgress()` object. + + .. method:: add(progress) + + Add the cdrom to the sources.list file. The parameter *progress* + refers to an :class:`apt.progress.CdromProgress()` object. + +.. class:: SourceList + + This is for :file:`/etc/apt/sources.list`. + + .. method:: find_index(pkgfile) + + Return a :class:`IndexFile` object for the :class:`PackageFile` + *pkgfile*. + + .. method:: read_main_list + + Read the main list. + + .. method:: get_indexes(acq[, all]) + + Add the index files to the :class:`Acquire()` object *acq*. If *all* is + given and ``True``, all files are fetched. + + .. attribute:: list + + A list of :class:`MetaIndex` objects. + +String functions +---------------- +.. function:: base64_encode(string) + + Encode the given string using base64, e.g:: + + >>> apt_pkg.base64_encode(u"A") + 'QQ==' + +.. function:: check_domain_list(host, list) + + See if Host is in a ',' separated list, e.g.:: + + apt_pkg.check_domain_list("alioth.debian.org","debian.net,debian.org") + +.. function:: dequote_string(string) + + Dequote the string specified by the parameter *string*, e.g.:: + + >>> apt_pkg.dequote_string("%61%70%74%20is%20cool") + 'apt is cool' + +.. function:: quote_string(string, repl) + + For every character listed in the string *repl*, replace all occurences in + the string *string* with the correct HTTP encoded value: + + >>> apt_pkg.quote_string("apt is cool","apt") + '%61%70%74%20is%20cool' + +.. function:: size_to_str(size) + + Return a string presenting the human-readable version of the integer + *size*. When calculating the units (k,M,G,etc.) the size is divided by the + factor 1000. + + Example:: + + >>> apt_pkg.size_to_str(10000) + '10.0k' + +.. function:: string_to_bool(input) + + Parse the string *input* and return one of **-1**, **0**, **1**. + + .. table:: Return values + + ===== ============================================= + Value Meaning + ===== ============================================= + -1 The string *input* is not recognized. + 0 The string *input* evaluates to **False**. + +1 The string *input* evaluates to **True**. + ===== ============================================= + + Example:: + + >>> apt_pkg.string_to_bool("yes") + 1 + >>> apt_pkg.string_to_bool("no") + 0 + >>> apt_pkg.string_to_bool("not-recognized") + -1 + +.. function:: str_to_time(rfc_time) + + Convert the :rfc:`1123` conforming string *rfc_time* to the unix time, and + return the integer. This is the opposite of :func:`TimeRFC1123`. + + Example:: + + >> apt_pkg.str_to_time('Thu, 01 Jan 1970 00:00:00 GMT') + 0 + +.. function:: time_rfc1123(seconds) + + Format the unix time specified by the integer *seconds*, according to the + requirements of :rfc:`1123`. + + Example:: + + >>> apt_pkg.time_rfc1123(0) + 'Thu, 01 Jan 1970 00:00:00 GMT' + + +.. function:: time_to_str(seconds) + + Format a given duration in a human-readable manner. The parameter *seconds* + refers to a number of seconds, given as an integer. The return value is a + string with a unit like 's' for seconds. + + Example:: + + >>> apt_pkg.time_to_str(3601) + '1h0min1s' + +.. function:: upstream_version(version) + + Return the string *version*, eliminating everything following the last + '-'. Thus, this should be equivalent to ``version.rsplit('-', 1)[0]``. + +.. function:: uri_to_filename(uri) + + Take a string *uri* as parameter and return a filename which can be used to + store the file, based on the URI. + + Example:: + + >>> apt_pkg.uri_to_filename('http://debian.org/index.html') + 'debian.org_index.html' + + +.. function:: version_compare(a, b) + + Compare two versions, *a* and *b*, and return an integer value which has + the same characteristic as the built-in :func:`cmp` function. + + .. table:: Return values + + ===== ============================================= + Value Meaning + ===== ============================================= + > 0 The version *a* is greater than version *b*. + = 0 Both versions are equal. + < 0 The version *a* is less than version *b*. + ===== ============================================= + + + + +Module Constants +---------------- +.. _CurStates: + +Package States +^^^^^^^^^^^^^^^ +.. data:: CURSTATE_CONFIG_FILES +.. data:: CURSTATE_HALF_CONFIGURED +.. data:: CURSTATE_HALF_INSTALLED +.. data:: CURSTATE_INSTALLED +.. data:: CURSTATE_NOT_INSTALLED +.. data:: CURSTATE_UNPACKED + +.. _InstStates: + +Installed states +^^^^^^^^^^^^^^^^ +.. data:: INSTSTATE_HOLD +.. data:: INSTSTATE_HOLD_REINSTREQ +.. data:: INSTSTATE_OK +.. data:: INSTSTATE_REINSTREQ + +.. _Priorities: + +Priorities +^^^^^^^^^^^ +.. data:: PRI_EXTRA +.. data:: PRI_IMPORTANT +.. data:: PRI_OPTIONAL +.. data:: PRI_REQUIRED +.. data:: PRI_STANDARD + + +.. _SelStates: + +Select states +^^^^^^^^^^^^^ +.. data:: SELSTATE_DEINSTALL +.. data:: SELSTATE_HOLD +.. data:: SELSTATE_INSTALL +.. data:: SELSTATE_PURGE +.. data:: SELSTATE_UNKNOWN + + +Build information +^^^^^^^^^^^^^^^^^ +.. data:: DATE + + The date on which this extension has been compiled. + +.. data:: LIB_VERSION + + The version of the apt_pkg library. This is **not** the version of apt, + nor the version of python-apt. + +.. data:: TIME + + The time this extension has been built. + +.. data:: VERSION + + The version of apt (not of python-apt). |