How to completely delete files on the server using PHP

It is a common requirement to implement PHP on the server to completely delete files. However, completely deleting files is sometimes more troublesome than we think. In this article, we will explain how to completely delete files on the server using PHP.

Step 1: Find the file to delete

First, we need to specify the file to delete. We can get the file name in many ways, such as getting the file name from the input of the form, or getting the file name from the database. In this article, we assume that the file name is obtained.

Step 2: Check if the file exists

Before we delete the file completely, we need to make sure that the file exists. If the file doesn't exist, we don't have to delete it. Therefore, we will use PHP's file_exists() function to check if the file exists. If the file does not exist, we will output an error message and exit the deletion script:

if (file_exists($filename)) {
   // Continue with deletion
} else {
   echo "Error: File not found.";
   exit();
}

Step 3: Open the file and close the resource

Before we delete the file, we need to make sure it is not in Using. If the file is open, we cannot delete it. Therefore, we will open the file using PHP's fopen() function and close the file resource using the fclose() function:

$handle = fopen($filename, "w");
fclose($handle);

This will open the file and immediately close it. If the file cannot be opened, an error message will be output and the removal script will exit.

Step 4: Delete file content

Although we have closed the file resource, we must ensure that the file content is completely deleted. Otherwise, the contents of the file may be leaked even if we remove the file name from the file system. Therefore, we will use PHP's file_put_contents() function to write an empty string to the file:

file_put_contents($filename, "");

This will make the contents of the file an empty string. Now, even if we have removed the file name, the contents of the file will not be revealed.

Step 5: Delete the filename

Finally, we will delete the filename from the file system using PHP’s unlink() function:

unlink($filename);

This will completely delete the file, and ensure that it no longer discloses any file contents.

Conclusion

In this article, we introduced how to completely delete files using PHP. Although this is a relatively simple process, we must be careful to ensure that the file contents are not leaked. If you will be deleting a file using the above code, please back up the file before deleting it. This will ensure you don't delete files by mistake.

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