Fsdb::Filter::dbcolcopylast

NAME

dbcolcopylast - create new columns that are copies of prior columns

SYNOPSIS

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

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.

OPTIONS

-e EmptyValue or --empty

Specify the value newly created columns get.

This module also supports the standard fsdb options:

-i or --input InputSource

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

-o or --output OutputDestination

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

--autorun or --noautorun

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

--help

Show help.

--man

Show full manual.

SAMPLE USAGE

Input:
#fsdb test
a
b

Command:
cat data.fsdb | dbcolcopylast foo

Output:
#fsdb test foo
a -
b -

SEE ALSO

Fsdb.

CLASS FUNCTIONS

new
$filter = new Fsdb::Filter::dbcolcopylast(@arguments);

Create a new dbcolcopylast object, taking command-line arguments.

set_defaults
$filter->set_defaults();

Internal: set up defaults.

parse_options
$filter->parse_options(@ARGV);

Internal: parse command-line arguments.

setup
$filter->setup();

Internal: setup, parse headers.

run
$filter->run();

Internal: run over each rows.

AUTHOR and COPYRIGHT

Copyright (C) 1991-2022 by John Heidemann <johnh AT isi DOT edu>

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