Home/ Questions/Q 4088146
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-20T18:56:41+00:00

I need to check if a file that existed in a directory on the

  • 0

I need to check if a file that existed in a directory on the server is the same file that was there say 5 minutes ago?

On a specific directory, I’m deleting and recreating a file with the same name every few minutes. A script is to access the file say every 2 mins. So at time t, the script checks the file and do stuffs. Then at time t+1, the file is deleted and recreated (same name but maybe different content). Then at time t+2, the script again looks for the file.

So in the second check , is there a way to check whether the file has been changed or not (without having to read the content)??

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    The first idea that comes to mind to determine whether a file has changed is to check its modification time, using the filemtime() function.

    But I’m guessing this will not quite work, as you are deleting and re-creating the file regularly.

    So, in your case, a very quick *(but not safe, of course)* first way is to **check the size of the file** : if it has changed, it is not the same file.

    In PHP, the size of a file can be determined using the [**`filesize()`**][2] function.

    Then, if the size has not changed, you’ll generally want to **calculate a hash of the file’s content** — which is generally either an [md5][3] or [sha1][4] hash.

    In PHP, you’ll use one of the following functions, depending on which algorithm you want to work with :

    • 0