
                                 Producer.pm
                             Version 1.4 (and up)

  What is it?
  -----------

  Producer.pm is a module that provides methods to fork off a subroutine or
  system call and return handles on the standard output (STDOUT and STDERR).
  If you have (for example) a subroutine that processes a very large text file
  and performs a task on each line, but you need to perform further processing
  with either other subroutines or in main, normally you would have to wait
  until the subroutine returns to get its output (either by returning it or
  opening a temporary file that it produced) and continue processing.  If the
  subroutine prints its output to STDOUT (and STDERR) or you can edit it to do
  so, you can call it using a producer so that you can use the returned handle
  to continuously process each line as it's "produced".  You can chain
  subroutines together like this by having your subroutine itself create a
  Producer.  This is similar to using open() to run a system call, except that
  with this module, you can get a handle on STDERR and use it with subroutines
  as well.

  Documentation
  -------------

  After installation, run `perldoc IO::Pipe::Producer` on the command line.

  Installation
  ------------

  gzip -d IO-Pipe-Producer-1.4.tar.gz
  tar -xvf IO-Pipe-Producer-1.4.tar
  cd IO-Pipe-Producer-1.4
  perl Build.PL
  ./Build
  ./Build test
  ./Build install

  OR:

  Locate where your Pipe.pm module is (by searching the @INC directories).
    Note: It should be in .../IO/. 
  cd to that directory.
  Create a directory called 'Pipe'.
  Copy ./lib/IO/Pipe/Producer.pm to the Pipe directory you created.

  Change History
  --------------

  2003/03/07 robleach 1.0

    Initial version.

  2005/04/11 robleach 1.1

    I added the ability to return handles on both standard output and standard
    error (when called in array context).  I also added a subroutine to do the
    same thing with a system call (as opposed to a subroutine call).

  2005/04/11 robleach 1.2

    I added the ability to return handles on both standard output and standard
    error (when called in array context).  I also added a subroutine to do the
    same thing with a system call (as opposed to a subroutine call).

  2005/04/11 robleach 1.3

    This is a modular version of producer_fork.pl.  I changed the method names,
    made a constructor, and changed the documentation.  It now ISA IO::Pipe and
    all the file handles returned are IO::Pipe::Producer instances.

  2005/05/04 robleach 1.4

    I incorporated Carp.pm, pod documentation, created $Producer::VERSION and
    $Producer::errstr variables, and edited/updated some comments.

  Licensing
  ---------

  This software and ancillary information (herein called "SOFTWARE") called
  Producer.pm is made available under the terms described here.  The
  SOFTWARE has been approved for release with associated LA-CC number
  LA-CC-05-060.

  Unless otherwise indicated, this software has been authored by an employee or
  employees of the University of California, operator of the Los Alamos
  National Laboratory under Contract No. W-7405-ENG-36 with the U.S. Department
  of Energy.  The U.S. government has rights to use, reproduce, and distribute
  this SOFTWARE.  The public may copy, distribute, prepare derivative works and
  publicly display this SOFTWARE without charge, provided that this notice and
  any statement of authorship are reproduced on all copies.  Neither the
  government nor the university makes any warranty, express or implied, or
  assumes any liability or responsibility for the use of this SOFTWARE.

  If SOFTWARE is modified to produce derivative works, such modified SOFTWARE
  should be clearly marked, so as not to confuse it with the version available
  from LANL.


  Author
  ------

  Robert W. Leach
  robleach@lanl.gov
  Los Alamos National Laboratory
  Bioscience Division, B5 (Genome Sequencing and Computational Biology)
  Biodefense Team
  MS M888
  Los Alamos, NM 87545
