How can I select and upload multiple files with HTML and PHP, using HTTP POST?

You can use the following HTML code to create a form that allows users to select and upload multiple files:

<form action="upload.php" method="post" enctype="multipart/form-data">
  Select files to upload:
  <input type="file" name="files[]" multiple>
  <input type="submit" value="Upload">
</form>

The enctype attribute specifies that the form will be sent as multipart/form-data, which is the encoding required for file uploads. The multiple attribute of the input element allows the user to select multiple files at once.

Then, in your PHP code, you can access the uploaded files using the $_FILES superglobal array. Here's an example of how you can handle the file uploads in PHP:

<?php

$uploaded_files = $_FILES['files'];

foreach ($uploaded_files['name'] as $key => $name) {
  $tmp_name = $uploaded_files['tmp_name'][$key];
  $error = $uploaded_files['error'][$key];
  $size = $uploaded_files['size'][$key];

  // Check for errors
  if ($error == UPLOAD_ERR_OK) {
    // Move the uploaded file to the desired location
    move_uploaded_file($tmp_name, "uploads/$name");
  }
}

?>

This code iterates over the uploaded files and checks for any errors. If there are no errors, it moves the uploaded file to the uploads directory using the move_uploaded_file function.

We hope this helps! Let us know if you have any questions.