NAME

       Dpkg::Changelog - base class to implement a changelog parser

DESCRIPTION

       Dpkg::Changelog is a class representing a changelog file as an array of changelog entries
       (Dpkg::Changelog::Entry).  By deriving this object and implementing its parse method, you
       add the ability to fill this object with changelog entries.

   FUNCTIONS
       my $c = Dpkg::Changelog->new(%options)
           Creates a new changelog object.

       $c->load($filename)
           Parse $filename as a changelog.

       $c->set_options(%opts)
           Change the value of some options. "verbose" (defaults to 1) defines whether parse
           errors are displayed as warnings by default. "reportfile" is a string to use instead
           of the name of the file parsed, in particular in error messages. "range" defines the
           range of entries that we want to parse, the parser will stop as soon as it has parsed
           enough data to satisfy $c->get_range($opts{range}).

       $c->reset_parse_errors()
           Can be used to delete all information about errors occurred during previous parse
           runs.

       $c->parse_error($file, $line_nr, $error, [$line])
           Record a new parse error in $file at line $line_nr. The error message is specified
           with $error and a copy of the line can be recorded in $line.

       $c->get_parse_errors()
           Returns all error messages from the last parse run.  If called in scalar context
           returns a human readable string representation. If called in list context returns an
           array of arrays. Each of these arrays contains

           1.  a string describing the origin of the data (a filename usually). If the reportfile
               configuration option was given, its value will be used instead.

           2.  the line number where the error occurred

           3.  an error description

           4.  the original line

       $c->set_unparsed_tail($tail)
           Add a string representing unparsed lines after the changelog entries.  Use undef as
           $tail to remove the unparsed lines currently set.

       $c->get_unparsed_tail()
           Return a string representing the unparsed lines after the changelog entries. Returns
           undef if there's no such thing.

       @{$c}
           Returns all the Dpkg::Changelog::Entry objects contained in this changelog in the
           order in which they have been parsed.

       $c->get_range($range)
           Returns an array (if called in list context) or a reference to an array of
           Dpkg::Changelog::Entry objects which each represent one entry of the changelog. $range
           is a hash reference describing the range of entries to return. See section "RANGE
           SELECTION".

       $c->abort_early()
           Returns true if enough data have been parsed to be able to return all entries selected
           by the range set at creation (or with set_options).

       $c->save($filename)
           Save the changelog in the given file.

       $c->output()
       "$c"
           Returns a string representation of the changelog (it's a concatenation of the string
           representation of the individual changelog entries).

       $c->output($fh)
           Output the changelog to the given filehandle.

       my $control = $c->dpkg($range)
           Returns a Dpkg::Control::Changelog object representing the entries selected by the
           optional range specifier (see "RANGE SELECTION" for details).  Returns undef in no
           entries are matched.

           The following fields are contained in the object:

           Source
               package name (in the first entry)

           Version
               packages' version (from first entry)

           Distribution
               target distribution (from first entry)

           Urgency
               urgency (highest of all printed entries)

           Maintainer
               person that created the (first) entry

           Date
               date of the (first) entry

           Closes
               bugs closed by the entry/entries, sorted by bug number

           Changes
               content of the the entry/entries

       my @controls = $c->rfc822($range)
           Returns a Dpkg::Index containing Dpkg::Control::Changelog objects where each object
           represents one entry in the changelog that is part of the range requested (see "RANGE
           SELECTION" for details). For the format of such an object see the description of the
           "dpkg" method (while ignoring the remarks about which values are taken from the first
           entry).

RANGE SELECTION

       A range selection is described by a hash reference where the allowed keys and values are
       described below.

       The following options take a version number as value.

       since
           Causes changelog information from all versions strictly later than version to be used.

       until
           Causes changelog information from all versions strictly earlier than version to be
           used.

       from
           Similar to "since" but also includes the information for the specified version itself.

       to  Similar to "until" but also includes the information for the specified version itself.

       The following options don't take version numbers as values:

       all If set to a true value, all entries of the changelog are returned, this overrides all
           other options.

       count
           Expects a signed integer as value. Returns "value" entries from the top of the
           changelog if set to a positive integer, and "abs(value)" entries from the tail if set
           to a negative integer.

       offset
           Expects a signed integer as value. Changes the starting point for "count", either
           counted from the top (positive integer) or from the tail (negative integer). "offset"
           has no effect if "count" wasn't given as well.

       Some examples for the above options. Imagine an example changelog with entries for the
       versions 1.2, 1.3, 2.0, 2.1, 2.2, 3.0 and 3.1.

                   Range                           Included entries
        C<{ since =E<gt> '2.0' }>                  3.1, 3.0, 2.2
        C<{ until =E<gt> '2.0' }>                  1.3, 1.2
        C<{ from =E<gt> '2.0' }>                   3.1, 3.0, 2.2, 2.1, 2.0
        C<{ to =E<gt> '2.0' }>                     2.0, 1.3, 1.2
        C<{ count =E<gt> 2 }>                      3.1, 3.0
        C<{ count =E<gt> -2 }>                     1.3, 1.2
        C<{ count =E<gt> 3, offset=E<gt> 2 }>      2.2, 2.1, 2.0
        C<{ count =E<gt> 2, offset=E<gt> -3 }>     2.0, 1.3
        C<{ count =E<gt> -2, offset=E<gt> 3 }>     3.0, 2.2
        C<{ count =E<gt> -2, offset=E<gt> -3 }>    2.2, 2.1

       Any combination of one option of "since" and "from" and one of "until" and "to" returns
       the intersection of the two results with only one of the options specified.

AUTHOR

       Frank Lichtenheld, <frank@lichtenheld.de> Raphaël Hertzog, <hertzog@debian.org>