IO::OpenFused

#!/usr/bin/perl 

use strict;
use warnings;

use POSIX qw( dup pipe );
use IO::File;
use IO::Handle;
use Data::Dump qw( dump );

sub openstream {
    my ( $fhx, @rest ) = @_;

    # Copy STDOUT and STDERR for resurrection.

    my $oldstdout = dup( fileno(*STDOUT) );
    my $oldstderr = dup( fileno(*STDERR) );

    # Generate a pipe to accept data from child process.
    my ( $response_r, $response_w ) = POSIX::pipe();

    # Put Perl handles on the pipe.
    my $responder = IO::Handle->new->fdopen( $response_r, 'r' );
    my $writer    = IO::Handle->new->fdopen( $response_w, 'w' );
    my $tstdout  = IO::Handle->new->fdopen( $oldstdout, 'w' ); 
    $responder->autoflush(1);
    $writer->autoflush(1);
    $tstdout->autoflush(1);

    # Return the handle to the user.
    $_[0] = $responder;

    # Reopen STDERR and STDOUT to point to the pipe.
    open *STDERR, '>>&=', $response_w;
    open *STDOUT, '>>&=', $response_w;
  
    # Run the users app with the new stuff.
    {
        if( not my $pid = fork() ){   
	    select *STDERR; $|++;
    	    select *STDOUT; $|++;
            system @rest;
            exit;
        }
    }
    open *STDERR, '>>&=', $oldstderr;
    open *STDOUT, '>>&=', $oldstdout;
}

openstream my $fh, qw( perl evil.pl );

while ( my $line = <$fh> ) {
    print dump $line;
}