NAME

       Dpkg::Checksums - generate and manipulate file checksums

DESCRIPTION

       This module provides a class that can generate and manipulate various file checksums as
       well as some methods to query information about supported checksums.

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
           "name" (returns the name of the digest algorithm), "regex" for the regular expression
           describing the common string representation of the checksum, and "strong" for a
           boolean describing whether the checksum algorithm is considered cryptographically
           strong.

METHODS

       $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 or verify 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, and
           the caller did not request that it be updated with the boolean "update" option.

       $ck->add_from_string($alg, $value, %opts)
           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, and the
           caller did not request that it be updated with the boolean "update" option.

       $ck->add_from_control($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.

       $bool = $ck->has_strong_checksums($file)
           Return a boolean on whether the file has a strong checksum.

       $ck->export_to_string($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.

CHANGES

   Version 1.04 (dpkg 1.20.0)
       Remove warning: For obsolete property 'program'.

   Version 1.03 (dpkg 1.18.5)
       New property: Add new 'strong' property.

       New member: $ck->has_strong_checksums().

   Version 1.02 (dpkg 1.18.0)
       Obsolete property: Getting the 'program' checksum property will warn and return undef, the
       Digest module is used internally now.

       New property: Add new 'name' property with the name of the Digest algorithm to use.

   Version 1.01 (dpkg 1.17.6)
       New argument: Accept an options argument in $ck->export_to_string().

       New option: Accept new option 'update' in $ck->add_from_file() and
       $ck->add_from_control().

   Version 1.00 (dpkg 1.15.6)
       Mark the module as public.