How do I make a temporary file name?

    BEGIN {
        use IO::File;
        use Fcntl;
        my $temp_dir = -d '/tmp' ? '/tmp' : $ENV{TMP} || $ENV{TEMP};
        my $base_name = sprintf("%s/%d-%d-0000", $temp_dir, $$, time());
        sub temp_file {
            my $fh = undef;
            my $count = 0;
            until (defined($fh) || $count > 100) {
                $base_name =~ s/-(\d+)$/"-" . (1 + $1)/e;
                $fh = IO::File->new($base_name, O_WRONLY|O_EXCL|O_CREAT, 0644)
            }
            if (defined($fh)) {
                return ($fh, $base_name);
            } else {
                return ();
            }
        }
    }

Or you could simply use IO::Handle::new_tmpfile.