This is getting me all sorts of frustrated. I have reverted to trying a simple test script and external program. The external program does nothing more than print a counter and then sleep for 1 second. I cannot seem to get its output while it is executing...Here is the code for both. Any help would be GREATLY appreciated...

the "child" program: 

#!/usr/bin/env perl

use strict;
use warnings;
use 5.016;
use Carp qw(cluck carp croak);

my $c=1;
for(1..15) {
    say 'COUNT: '.$c;
    $c++;
    sleep(1);
}

[download]

And here is the "parent" program...again, I am open to ANY solution that works. By "works", I mean that I need the output of the child program to be printed as it comes in. For the "real" program, I will need to send a web socket message every time output is received from the child program...the output will be a progress indicator (e.g. 10% complete, 15% complete, etc.).

First, with Capture::Tiny: (no dice) 

#!/usr/bin/env perl

use strict;
use warnings;
use 5.016;
use Carp qw(cluck carp croak);
use Data::Dumper;
use Capture::Tiny ':all';

local $| = 1;

my $cmd = "/tempssd/bossert/bin/testchild.pl &";

my ($stdout, $stderr, @result) = tee { system($cmd); };

while (my $line = <$stdout>) {
    say 'GOT: '.$line;
    last if $line =~ m/^FINISHED/;
}

[download]

Next, with IPC::Run: (Note, I get the STDOUT AFTER it runs...and it seems that the code ref for the stdout handling never fires. 

#!/usr/bin/env perl

use strict;
use warnings;
use 5.016;
use Carp qw(cluck carp croak);
use Data::Dumper;
use IPC::Run qw(run);

local $| = 1;

my @cmd = ("/tempssd/bossert/bin/testchild.pl");

run \@cmd, '<', \undef,'>&',\&stdoutH or die "cat: $?";

sub stdoutH {
    my ($in) = @_;
    chomp $in;
    say 'STDOUT: '.$in;
}

[download]

In reply to Re^2: capture periodic updates from external program by mabossert
in thread capture periodic updates from external program by mabossert

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