my $file = 'C:/tmp.zip';
open F, $file or die $!; 
read( F, my $buf, 1024 );
close F;
print is_text($buf) ? "$file is TEXT\n" : "$file is BIN\n";

# alternatively you can just...
print -T $file ? "-T $file is TEXT\n" : "-T $file is BIN\n";

sub is_text {
    my ($data) = @_;
  return 0 unless $data;
  return 0 if $data =~ m![\x00-\x08\x0b\x0e-\x1f]!;
  return 1;
}