Why PHP can't see an uploaded file?-CodePudding

I have an index.php and upload.php. In index.php is a form action="upload.php" with input type="file" id="file" name="file" tag in it. PHP code is:

<?php
$file = $_FILES['file'];
print_r($file);
echo "test";
?>

For some reason it shows echo but print_r() doesn't work.

I've tried rewriting the code. Adding other identificators for the input tag inside index.php but it still doesn't work. What am I doing wrong?

CodePudding user response：

maybe you are forgot enctype="multipart/form-data"

try this version


<form action="upload.php" method="post" enctype="multipart/form-data">
  <p><input type="file" name="file">
  <p><button type="submit">Submit</button>
</form>
</body>
</html>

CodePudding user response：

Assuming that you can already upload the file, such as using form like the following:

<form action="upload.php" method="post" enctype="multipart/form-data">
  <p><input type="file" name="file">
  <p><button type="submit">Submit</button>
</form>
</body>
</html>

Then if you want to display the image at the receiving "upload.php", you may use:

If the image is JPG/JPEG type:

<?php
$string1= base64_encode(file_get_contents($_FILES["file"]["tmp_name"]));

echo '<img src="data:image/jpeg;base64, ' .  $string1  . '"/>';

?>

If the image is PNG type:

<?php
$string1= base64_encode(file_get_contents($_FILES["file"]["tmp_name"]));

echo '<img src="data:image/png;base64, ' .  $string1  . '"/>';

?>

Note: actually we usually save the uploaded file in the server (for later display), or store the binary data into a BLOB field in a db table, but the above code is to demonstrate how one can do to immediately display the uploaded image.

CodePudding user response：

You did not mention what type of file is being uploaded. Here is an example of a image upload. With multiple image selections allowed.

<form action="upload.php" method="post" enctype="multipart/form-data">
Get a Photo from your device <br>
<input type="file" name="image1[]" multiple accept="image/png, image/jpeg, image/gif, image/webp" /><br>
<button type="submit">Upload Photo</button>
</form>

And the upload PHP:

foreach ($_FILES["image1"]["error"] as $key => $error) {
    if ($error == 0 ) {
        $tmp_name = $_FILES["image1"]["tmp_name"][$key];
        $name = basename($_FILES["image1"]["name"][$key]);
        $result = move_uploaded_file($tmp_name, "$uploads_dir/$name");
        if($result == false){echo "not moved\n";}
    }
    if($error > 0){echo "error $error\n";}
}

To ascertain the type of image uploaded:

 switch(strtolower($_FILES['image1']['type'])){
  case 'image/jpeg':
    $image = @imagecreatefromjpeg($_FILES['image1']['tmp_name']);
    if ($image !== false){$save = true;break;}
  case 'image/png':
    $image = @imagecreatefrompng($_FILES['image1']['tmp_name']);
    if ($image !== false){$save = true;break;}
  case 'image/gif':
    $image = @imagecreatefromgif($_FILES['image1']['tmp_name']);
    if ($image !== false){$save = true;break;}
  case 'image/webp':
    $image = @imagecreatefromwebp($_FILES['image1']['tmp_name']);
    if ($image !== false){$save = true;break;}
  default:
    $img = @getimagesize($_FILES['image1']['tmp_name']);
    switch(strtolower($img['mime'])){
    case 'image/jpeg':
      $image = @imagecreatefromjpeg($_FILES['image1']['tmp_name']);
      if ($image !== false){$save = true;break;}
    case 'image/png':
      $image = @imagecreatefrompng($_FILES['image1']['tmp_name']);
      if ($image !== false){$save = true;break;}
    case 'image/gif':
      $image = @imagecreatefromgif($_FILES['image1']['tmp_name']);
      if ($image !== false){$save = true;break;}
    default:
      $filename = $_FILES['image1']['name'];
      $ext = substr($filename,-3);
      switch(strtolower($ext)){
      case 'jpg':
        $image = @imagecreatefromjpeg($_FILES['image1']['tmp_name']);
        if ($image !== false){$save = true;break;}
      case 'ebp':
        $image = @imagecreatefromwebp($_FILES['image1']['tmp_name']);
        if ($image !== false){$save = true;break;}
      case 'gif':
        $image = @imagecreatefromgif($_FILES['image1']['tmp_name']);
        if ($image !== false){$save = true;break;}
      case 'png':
        $image = @imagecreatefrompng($_FILES['image1']['tmp_name']);
        if ($image !== false){$save = true;break;}
      default:
        $image = @imagecreatefromjpeg($_FILES['image1']['tmp_name']);
        if ($image !== false){$save = true;break;}
        $image = @imagecreatefrompng($_FILES['image1']['tmp_name']);
        if ($image !== false){$save = true;break;}
        $image = @imagecreatefromgif($_FILES['image1']['tmp_name']);
        if ($image !== false){$save = true;break;}
      }
    }
  }