Alien::Package - an object that represents a package
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.
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.
- 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.
- $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.
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.
Joey Hess <
[email protected]>