能够删除文件，无法复制或修改它们-PHP

Question

Using the following code I receive an error when trying to copy a file, or anything else I try to do with it. I am however able to use almost identical code to delete the file.

$file = "img1.jpg";

if (!copy($file, "img2.jpg")) {
  echo ("Error copying $file");
} else {
  echo ("Copied $file");
}

Delete Code:

if (!unlink($file)) {
  echo ("Error deleting $file");
} else {
  echo ("Deleted $file");
}

Anyone know why it might be doing this?

Edit: Apache owns the files but seems to be unable to read or write them as per is_readable and is_writeable

Edit2: added second argument to the copy code. This was not the problem, just me making errors in posting this question.

Answer 1

$file = "img1.jpg";
$newFile = "img1_copy.jpg";

if (!copy($file, $newFile)) {
  echo ("Error copying $file");
} else {
  echo ("Copied $file");
}

http://php.net/manual/en/function.copy.php

The function copy() requires 2 arguments.

Answer 2

Change all permissions manually for each file, so that www-data owns it, and www-data (the group) can read and write to it. Apache did something weird and while the apache user owned and could read and write to the file, the group www-data was unable to do either.