The following module was proposed for inclusion in the Module List:
modid: IO::Pipe::Producer
DSLIP: RdpOp
description: Get STDOUT & STDERR handles on a subroutine.
userid: ROBLEACH (Robert Leach)
chapterid: 21 (File_Handle_Input_Output)
communities:
similar:
rationale:
If you have a series of sequential steps to perform to process a
stream of input and each of those steps is somewhat complex, you
might want to encapsulate those steps in their own subroutines, but
doing so on a large file would mean you have to wait for the last
step to start before you start getting output from your script:
@results1 = step1($fh); @results2 = step2(\@results1); @results3 =
step3(\@results2); print(@results3);
Instead, you can start getting results right away if each step was
reading and printing to standard in & out and you called them as
forked producers. You could chain them together like this:
print(<$producer->getSubroutineProducer(\&step3,
$producer->getSubroutineProducer(\&step2,
$producer->getSubroutineProducer(\&step1,$fh)))>);
This is basically piping, which is why I selected to put
Producer.pm in IO::Pipe. Forking and piping between subroutines is
the unique part of the approach. I've already used this to
encapsulate some C functions I converted using SWIG. The C function
was printing to standard output (and standard error) from a number
of places throughout a complex library and I wanted to be able to
run it and capture the output to return as a string and it worked
beautifully.
enteredby: ROBLEACH (Robert Leach)
enteredon: Fri Nov 16 20:43:02 2012 GMT
The resulting entry would be:
IO::Pipe::
::Producer RdpOp Get STDOUT & STDERR handles on a subroutine. ROBLEACH
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