use strict;
use FileHandle;
use IPC::Open3;
use IO::Select;

my @command = @ARGV;

# ------------------------------------------------------------------------------
# File handles that child process will write to
# Dont use them for anything until AFTER the open3() call,
# as they dont get filenos until then!
my $childSTDOUT = FileHandle->new;
my $childSTDERR = FileHandle->new;

# ------------------------------------------------------------------------------
# runs the child process, hooking us up to its FHs
my $childPID = open3("<&STDIN", $childSTDOUT, $childSTDERR, @command);
if ( !$childPID ) {
  _log("RUN ERROR: COMMAND='@command' open3/exec failed: $!");
};

# This gives a new warning under 5.8.3 as it reuses 0 which was closed by open3
my $fhLog = FileHandle->new(">>$childPID.log") 
  or _log("RUN WARNING: Failed to create $childPID.log because '$!'");

_log("RUN BEGIN: PID=$childPID COMMAND='@command'");

# select based non-blocking IO
my $sel = IO::Select->new();
$sel->add($childSTDOUT);
$sel->add($childSTDERR);

# non-blocking select timeouts (seconds). Arbitary
my ($line, $bytes, $total_bytes);

# ------------------------------------------------------------------------------
# Loop reading child output
# control flags
my $childLives = 1;
my $childActivity = 0;
while ($childLives) {

  my @read = $sel->can_read(60);
  my $should = 0;
  my $bytes = 0;

  foreach my $fh ( @read ) {
    $should++;
    # _read read from $fh and writes to $fhLog
    $bytes += _read($fh,$fhLog);
  }

  $childLives = 0 if $should and not $bytes;

}