NAME
Dpkg::Checksums - generate and manipulate file checksums
DESCRIPTION
This module provides an object that can generate and manipulate various
file checksums as well as some methods to query information about
supported checksums.
EXPORTED FUNCTIONS
@list = checksums_get_list()
Returns the list of supported checksums algorithms.
$bool = checksums_is_supported($alg)
Returns a boolean indicating whether the given checksum algorithm
is supported. The checksum algorithm is case-insensitive.
$value = checksums_get_property($alg, $property)
Returns the requested property of the checksum algorithm. Returns
undef if either the property or the checksum algorithm doesn't
exist. Valid properties currently include "program" (returns an
array reference with a program name and parameters required to
compute the checksum of the filename given as last parameter) and
"regex" for the regular expression describing the common string
representation of the checksum (as output by the program that
generates it).
OBJECT METHODS
my $ck = Dpkg::Checksums->new()
Create a new Dpkg::Checksums object. This object is able to store
the checksums of several files to later export them or verify them.
$ck->reset()
Forget about all checksums stored. The object is again in the same
state as if it was newly created.
$ck->add_from_file($filename, %opts)
Add checksums information for the file $filename. The file must
exists for the call to succeed. If you don't want the given
filename to appear when you later export the checksums you might
want to set the "key" option with the public name that you want to
use. Also if you don't want to generate all the checksums, you can
pass an array reference of the wanted checksums in the "checksums"
option.
It the object already contains checksums information associated the
filename (or key), it will error out if the newly computed
information does not match what's stored.
$ck->add_from_string($alg, $value)
Add checksums of type $alg that are stored in the $value variable.
$value can be multi-lines, each line should be a space separated
list of checksum, file size and filename. Leading or trailing
spaces are not allowed.
It the object already contains checksums information associated to
the filenames, it will error out if the newly read information does
not match what's stored.
$ck->add_from_control($control, %opts)
Read checksums from Checksums-* fields stored in the Dpkg::Control
object $control. It uses $self->add_from_string() on the field
values to do the actual work.
If the option "use_files_for_md5" evaluates to true, then the
"Files" field is used in place of the "Checksums-Md5" field. By
default the option is false.
@files = $ck->get_files()
Return the list of files whose checksums are stored in the object.
$bool = $ck->has_file($file)
Return true if we have checksums for the given file. Returns false
otherwise.
$ck->remove_file($file)
Remove all checksums of the given file.
$checksum = $ck->get_checksum($file, $alg)
Return the checksum of type $alg for the requested $file. This will
not compute the checksum but only return the checksum stored in the
object, if any.
If $alg is not defined, it returns a reference to a hash: keys are
the checksum algorithms and values are the checksums themselves.
The hash returned must not be modified, it's internal to the
object.
$size = $ck->get_size($file)
Return the size of the requested file if it's available in the
object.
$ck->export_to_string($alg, %opts)
Return a multi-line string containing the checksums of type $alg.
The string can be stored as-is in a Checksum-* field of a
Dpkg::Control object.
$ck->export_to_control($control, %opts)
Export the checksums in the Checksums-* fields of the Dpkg::Control
$control object.
AUTHOR
Raphal Hertzog <hertzog@debian.org>.