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>.