#!/usr/bin/env perl
use 5.012;
use warnings;

use Cwd qw/getcwd/;
use File::Temp qw/tempdir/;

my $cwd = getcwd;

for my $fs (@ARGV ? @ARGV : '.') {
    my $dir = tempdir(DIR => $fs, CLEANUP => 1);
    chdir $dir or die "Error in chdir() using $dir: $!";
    
    my ($fold_create, $fold_open, $rename);
    
    if (open my $foo, '>Foo') {
	my %names = map { $_ => 1 } glob('*');
	if ($names{foo}) {
	    $fold_create = 'lc';
	}
	elsif ($names{FOO}) {
	    $fold_create = 'uc';
	}
	else {
	    $fold_create = 'none';
	}
    }
    else {
	die "Error in open() using >Foo: $!";
    }
    
    if (rename 'Foo', 'fOo') {
	$rename = 'allowed';
    }
    else {
	$rename = 'disallowed';
    }
    
    if (open my $foo, '<foO') {
	$fold_open = 'yes';
    }
    else {
	$fold_open = 'none';
    }
    
    chdir $cwd or warn "Error in chdir() using $cwd: $!";
    say "$fs: fold_create=$fold_create, fold_open=$fold_open, rename=$rename";
}