#!/usr/bin/perl -w

#
# dbcolcopylast.pm
# Copyright (C) 1991-2022 by John Heidemann <johnh@isi.edu>
#
# This program is distributed under terms of the GNU general
# public license, version 2.  See the file COPYING
# in $dblibdir for details.
#


=head1 NAME

dbcolcopylast - create new columns that are copies of prior columns

=head1 SYNOPSIS

    dbcolcopylast [-e EMPTY] [column...]


=head1 DESCRIPTION

For each COLUMN, create a new column copylast_COLUMN
that is the last value for that column---that is,
the value of that column from the row before.


=head1 OPTIONS

=over 4

=item B<-e> EmptyValue or B<--empty>

Specify the value newly created columns get.

=back

=for comment
begin_standard_fsdb_options

This module also supports the standard fsdb options:

=over 4

=item B<-d>

Enable debugging output.

=item B<-i> or B<--input> InputSource

Read from InputSource, typically a file name, or C<-> for standard input,
or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.

=item B<-o> or B<--output> OutputDestination

Write to OutputDestination, typically a file name, or C<-> for standard output,
or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.

=item B<--autorun> or B<--noautorun>

By default, programs process automatically,
but Fsdb::Filter objects in Perl do not run until you invoke
the run() method.
The C<--(no)autorun> option controls that behavior within Perl.

=item B<--help>

Show help.

=item B<--man>

Show full manual.

=back

=for comment
end_standard_fsdb_options


=head1 SAMPLE USAGE

=head2 Input:

    #fsdb test
    a
    b

=head2 Command:

    cat data.fsdb | dbcolcopylast foo 

=head2 Output:

    #fsdb      test    foo
    a       -
    b       -


=head1 SEE ALSO

L<Fsdb>.


=cut


# WARNING: This code is derived from dbcolcopylast.pm; that is the master copy.

use Fsdb::Filter::dbcolcopylast;
my $f = new Fsdb::Filter::dbcolcopylast(@ARGV);
$f->setup_run_finish;  # or could just --autorun
exit 0;


=head1 AUTHOR and COPYRIGHT

Copyright (C) 1991-2022 by John Heidemann <johnh@isi.edu>

This program is distributed under terms of the GNU general
public license, version 2.  See the file COPYING
with the distribution for details.

=cut

1;