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Dpkg::Checksums(3perl)           libdpkg-perl           Dpkg::Checksums(3perl)

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.

1.21.22                           2023-05-11            Dpkg::Checksums(3perl)

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