setpipe

#!/usr/bin/perl
use strict;
use lib ($ENV{RLWRAP_FILTERDIR} or ".");
use RlwrapFilter;

my $cmd;
my $filter = RlwrapFilter->new;
$filter->help_text("Usage: rlwrap -z setpipe <command>\n"
                  ."Intercept line starting with | and pipe further output thru it.\n"
                  ."Use |<ret> to remove previously set pipe commands.\n");
$filter->input_handler(\&input);
$filter->output_handler(\&output);
$filter->run;

sub input {
    if (/^\|\s*$/) {
        undef $cmd;
    }
    elsif (/^\|/ ) {
        $cmd = substr($_, 1);
        return undef;
    }
    return $_;
}

sub output {
    if (defined $cmd) {
        # not reusing $fh because of buffring issues, 
        # that open/close should really be in &input.
        open(my $fh, '|-', 'sh', ('-c', $cmd));
        print $fh $_;
        close $fh;
        return undef;
    }
    return $_;
}