NAME

       Alien::Package - an object that represents a package

DESCRIPTION

       This is a perl object class that represents a package in an internal format usable by
       alien. The package may be a deb, a rpm, a tgz, or a slp package, etc. Objects in this
       class hold various fields of metadata from the actual packages they represent, as well as
       some fields pointing to the actual contents of the package. They can also examine an
       actual package on disk, and populate those fields. And they can build the actual package
       using the data stored in the fields.

       A typical use of this object class will be to instantiate an object from a class derived
       from this one, such as Alien::Package::Rpm. Feed the object a rpm file, thus populating
       all of its fields. Then rebless the object into the destination class, such as
       Alien::Package::Deb. Finally, ask the object to build a package, and the package has been
       converted.

FIELDS

       These fields are of course really just methods that all act similarly; allowing a value to
       be passed in to set them, or simply returning the value of the field if nothing is passed
       in. Child classes may override these fields to process input data, or to format output
       data. The general rule is that input data is modified to get things into a package-
       independant form, which is how the data is stored in the fields. When the value of a field
       is read, it too may be modified before it is returned, to change things into a form more
       suitable for the particular type of package.

       name
           The package's name.

       version
           The package's upstream version.

       release
           The package's distribution specific release number.

       arch
           The package's architecture, in the format used by Debian.

       maintainer
           The package's maintainer.

       depends
           The package's dependencies. Only dependencies that should exist on all target
           distributions can be put in here though (ie: lsb).

       group
           The section the package is in.

       summary
           A one line description of the package.

       description
           A longer description of the package. May contain multiple paragraphs.

       copyright
           A short statement of copyright.

       origformat
           What format the package was originally in.

       distribution
           What distribution family the package originated from.

       binary_info
           Whatever the package's package tool says when told to display info about the package.

       conffiles
           A reference to a list of all the conffiles in the package.

       files
           A reference to a list of all the files in the package.

       changelogtext
           The text of the changelog

       postinst
           The postinst script of the package.

       postrm
           The postrm script of the package.

       preinst
           The preinst script of the package.

       prerm
           The prerm script of the package.

       usescripts
           Only use the above scripts fields when generating the package if this is set to a true
           value.

       unpacked_tree
           Points to a directory where the package has been unpacked.

       owninfo
           If set this will be a reference to a hash, with filename as key, that holds
           ownership/group information for files that cannot be represented on the filesystem.
           Typically that is because the owners or groups just don't exist yet. It will be set at
           unpack time.

       modeinfo
           If set this will be a reference to a hash, with filename as key, that holds mode
           information for setuid files that have an entry in owninfo.  It will be set at unpack
           time.

METHODS

       init
           This is called by new(). It's a handy place to set fields, etc, without having to
           write your own new() method.

       install
           Simply installs a package file. The filename is passed.  This has to be overridden in
           child classes.

       test
           Test a package file. The filename is passed, should return an array of lines of test
           results. Child classes may implement this.

       filename
           Set/get the filename of the package the object represents.

           When it is set, it performs a scan of the file, populating most other fields with data
           from it.

           (This is just a stub; child classes should override it to actually do something.)

       scripts
           Returns a list of all non-empty maintainer scripts in the package.

       scan
           This method scans the file associated with an object, and populates as many other
           fields as it can with data from it.

       unpack
           This method unpacks the package into a temporary directory. It sets unpacked_tree to
           point to that directory.

           (This is just a stub method that makes a directory below the current working
           directory, and sets unpacked_tree to point to it. It should be overridden by child
           classes to actually unpack the package as well.)

       prep
           This method causes the object to prepare a build tree to be used in building the
           object. It expects that the unpack method has already been called. It takes the tree
           generated by that method, and mangles it somehow, to produce a suitable build tree.

           (This is just a stub method that all child classes should override.)

       cleantree
           This method should clean the unpacked_tree of any effects the prep and build methods
           might have on it.

       revert
           This method should ensure that the object is in the same state it was in before the
           prep method was called.

       build
           This method takes a prepped build tree, and simply builds a package from it. It should
           put the package in the current directory, and should return the filename of the
           generated package.

           (This is just a stub method that all child classes should override.)

       incrementrelease
           This method should increment the release field of the package by the specified number.

       DESTROY
           When an object is destroyed, it cleans some stuff up. In particular, if the package
           was unpacked, it is time now to wipe out the temporary directory.

       AUTOLOAD
           Handles all fields, by creating accessor methods for them the first time they are
           accessed.

CLASS DATA

       $Alien::Package::verbose
           If set to a nonzero value, the shell commands that are run should be output.  If set
           to a value greater than 1, any output of the commands should also be output.

CLASS METHODS

       These methods can be called on either an object or on the class itself.

       new Returns a new object of this class. Optionally, you can pass in named parameters that
           specify the values of any fields in the class.

       checkfile
           Pass it a filename, and it will return true if it looks like the file is a package of
           the type handled by the class.

       do  Runs a shell command. Is verbose or not depending on the value of
           $Alien::Package::verbose. Returns true if the command succeeds, false on failure.

       runpipe
           This is similar to backticks, but honors $Alien::Package::verbose, logging the command
           run if asked to. The output of the command is returned.

           The first parameter controls what to do on error. If it's true then any errors from
           the command will be ignored (and $? will be set). If it's false, errors will abort
           alien.

AUTHOR

       Joey Hess <joey@kitenet.net>