How can I delete a file using php? Using a linux server (if that matters).

Thanks for any help

Do I need to open the file before I can delete it?

no, the demo unlink code just shows a range of possibilities for its use
you can just unlink the file
but it is good to check if exists

Okay thanks, presumably if it doesn't exitst I'd have $fh = fopen('test.html', 'a') or die("Failed");

You should check if the file you want to delete is existed. Try to use the file_exists function so your code would be like that:

if (file_exists('test.html')) 
    unlink('test.html');
else echo "The file does not exist";