NAME

dbsubprocess - invoke a subprocess as a Fsdb filter object

SYNOPSIS

dbsubprocess program [arguments...]

DESCRIPTION

Run PROGRAM as a process, with optional ARGUMENTS as program arguments, feeding its standard input and standard output as fsdb streams.

This program is primarily for internal use by dbmapreduce.

Like dbpipeline, dbsubprocess program does have a Unix command; instead it is used only from within Perl.

OPTIONS

-w or --warnings

Enable warnings in user supplied code. (Default to include warnings.)

and the standard fsdb options:

-d

Enable debugging output.

-i or --input InputSource

Read from InputSource, typically a file, 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, 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:

    xxx

Command:

    xxx

Output:

    xxx

SEE ALSO

dbpipeline(1), Fsdb(3)

CLASS FUNCTIONS

new

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

Create a new dbsubprocess object, taking command-line arugments.

set_defaults

    $filter->set_defaults();

Internal: set up defaults.

parse_options

    $filter->parse_options(@ARGV);

Internal: parse options

setup

    $filter->setup();

Internal: setup, parse headers.

_subproc_postprocessor

    $filter->_subproc_postprocessor

(internal) Read output from the subprocess and convert back to a fsdb stream.

_dbsubprocess_open2

    ($pid, $from_child, $to_child) = _open2('some', 'cmd', 'and', 'args');

Cribbed off of IPC::Open3.pm to avoid leaking symbols in perl-5.10.0, but simplified considerably. Basically the Symbol.pm GENnn symbols were leaking, for whatever reason.

This command cannot fail (it will die if it fails).

run

    $filter->run();

Internal: run over all data rows.

finish

    $filter->finish();

Internal: write trailer.

AUTHOR and COPYRIGHT

Copyright (C) 1991-2008 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.

cpanm Fsdb

perl -MCPAN -e shell
install Fsdb