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

       Raphaël Hertzog <hertzog@debian.org>.

1.17.5                                             2013-12-10                                 Dpkg::Checksums(3)