#!/usr/bin/perl
use v5.14;
use warnings;
#use Fcntl;


my $FILE = shift or die "Need file to read\n";

# Don't set close-on-exec flag when we open a file handle
local $^F = 10;

say "Opening file";
open( my $in, '<', $FILE ) or die "Can't open '$FILE': $!\n";

# Clear the close-on-exec flag
#my $flags = fcntl $in, F_GETFD, 0 or die "fcntl F_GETFD: $!";
#fcntl $in, F_SETFD, $flags & ~FD_CLOEXEC or die "fcntl F_SETFD: $!";


$SIG{CHLD} = 'IGNORE';
my $child_pid = fork();
if( $child_pid ) {
    # Parent
    while(1) { sleep 10 }
}
else {
    # Child

    say "Forking child process";
    my $fd = fileno( $in );
    exec( 'perl', './fd_get.pl', $fd )
        or die "Could not exec: $!\n";
}