$File::Temp::KEEP_ALL = 0;
File::Temp::cleanup;

##</code><code>##

use strict;
use warnings;

use Capture::Tiny qw(capture);

use File::Temp 'tempdir';
$File::Temp::KEEP_ALL = 1; 

my $tmpdir = File::Temp::tempdir();

print "at1: ";system("ls /tmp | wc -l");
my ($stdout, $stderr) = capture {
 # do some system command
};
# now there are two more temp files in /tmp
# they should have not been there!
print "at2: ";system("ls /tmp | wc -l");

$File::Temp::KEEP_ALL = 0;
File::Temp::cleanup;

# they are still there
print "at3: ";system("ls /tmp | wc -l");

##</code><code>##

...
If the global variable $KEEP_ALL is true, the file or directory will not be removed.