use File::Temp qw/tempdir/;
use File::Basename qw/fileparse/;
use File::Spec::Functions qw/catfile/;

my $tmpdir = tempdir(CLEANUP=>1);
my $tfn = catfile($tmpdir, scalar fileparse($filename));
...

# - OR -

my ($fn,$dir) = fileparse($filename);
my $tmpdir = tempdir(DIR=>$dir, TEMPLATE=>'.XXXXXXXXXX', CLEANUP=>1 );
my $tfn = catfile($tmpdir, $fn);
...