The is_uploaded_file Function

The is_uploaded_file function checks whether the specified file was uploaded via a POST request. This is an important security check when working with uploaded files. The function takes one parameter - the path to the file to check, and returns true if the file was uploaded via POST, and false otherwise.

Syntax

phpis_uploaded_file(string $filename): bool

Example

Check if a file was uploaded via a form:

php<?php
  if (is_uploaded_file($_FILES['userfile']['tmp_name'])) {
    echo 'File was uploaded via HTTP POST';
  } else {
    echo 'File was NOT uploaded via HTTP POST';
  }
?>

Example

Using the function in combination with move_uploaded_file:

php<?php
  $temp_file = $_FILES['userfile']['tmp_name'];
  $target_file = 'uploads/' . $_FILES['userfile']['name'];
  
  if (is_uploaded_file($temp_file)) {
    move_uploaded_file($temp_file, $target_file);
    echo 'file uploaded successfully';
  } else {
    echo 'possible file upload attack';
  }
?>

See Also