File Exists PHP

Question

I am using this function to check if the file exists:

<?php
    header('Content-Type: text/html; charset=utf-8');
    //header('Accept-Ranges: bytes');

    $nome_real = $_FILES["Arquivo"]["name"];
    $pastadestino = "/pasta/$nome_real";

    //verifica antes de passar - para apagar o existente
    if (file_exists($pastadestino))
    {
        echo "OK";
    }
    else
    {
        echo "NOK";
    }
?>

However, it returns OK even if I leave the path empty. Or even if the file name is different, someone could explain me?

Answer 1

Trickster of the rascal 1:

The function file_exists(), despite the name, checks if the path exists, regardless of whether it is a file or directory.

When you leave the parameter empty, your test is the same as this:

if (file_exists( '/pasta/' ))

what should return true if the folder actually exists.

Solution:

The solution would be to exchange the function for is_file(), which is specific to files:

if (is_file($pastadestino))
    {
        echo "OK";
    }
    else
    {
        echo "NOK";
    }

If you want to check folders/directories only, there is the analog function is_dir(), that check if the path exists and is directory.

if (is_dir($pastadestino))
    {
        echo "OK";
    }
    else
    {
        echo "NOK";
    }

Trickster of the rascal 2:

Be careful if you need to scan files right after changing something in the filesystem, as all of the above functions have a cache in PHP.

Solution:

To make sure you are dealing with the updated path, there is the clearstatcache():

clearstatcache(); // Limpamos o cache de arquivos do PHP
if (is_file($pastadestino)) // is_dir() para pastas, is_file para arquivos.
    {
        echo "OK";
    }
    else
    {
        echo "NOK";
    }

Click on the names of the above functions to know more details, they are linked with online PHP documentation.