php if else error with form field

Question

My form has a input file type field.

<input type="file" name="file" size="80" value="">

when submitted and this field is empty the file upload part of my php script should be skipped. This does not seem to be happening. What I am getting is the wrong file type message popping. Nothing was populated in the field on the form so why is my if/else statement not being followed? What am I doing wrong?

<?php
// connect to datebase
require "master.db.php";


// this if(empty statement is not working?
// should be checking to see if the form field 'file' is populated if so check file
// type if not skip and update sql database with information in form field 'test'
if(!empty($_FILES))
{
    if ((($_FILES["file"]["type"] == "image/gif")
    || ($_FILES["file"]["type"] == "image/jpeg")
    || ($_FILES["file"]["type"] == "image/pjpeg"))
    && ($_FILES["file"]["size"] < 2097152))
    {
        // code here works - function is to upload the file - not part of my current problem
    }

    // currently this else statement is displayed regardless of 'file' input
    // wrong function for its intended purpose
    else
    {
        // wrong file type
        echo "Invalid file <br />";
        echo "Tryed to upload: " . $_FILES["file"]["name"] . "<br />";
        echo "Type: " . $_FILES["file"]["type"] . "<br />";
        echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb Max 2Mb <br />";
        echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br />";
        die;
    }
}
else 
{
// update other data in mysql database
$sql="UPDATE `characters` SET test='$test' WHERE ID='$id'";
$result=mysql_query($sql);

    // if successfully updated mysql.
    if($result){
        echo "<b>Update successful</b> <br />";
        echo "<a href='test.html'>View result</a>";
        touch('master.html');
        clearstatcache();
    }
    else
    {
        echo "Whoops: " . mysql_error(); ;
    }
    mysql_close();
}
?>

so remove `if(!empty($_FILES))` and replace with `if(isset($_FILES))` ? — webmaster alex l, Jun 09 '12 at 14:49

score 2 · Accepted Answer · edited May 23 '17 at 12:21

2

The browser will still send the input value, even though the value is empty. As a consequence, PHP will populate the $_FILES array with something like:

Array
(
    [file] => Array
        (
            [name] => 
            [type] => 
            [tmp_name] => 
            [error] => 4
            [size] => 0
        )

)

So instead of checking with isset/empty, I guess you should use PHP's native is_uploaded_file method. See this SO post for more info on checking if an optional file input was provided.

I'll try to clarify my answer. The reference I just gave suggests using file_exists and is_uploaded_file. According to the PHP manual only using is_uploaded_file is sufficient. In fact, I can imagine is_uploaded_file looks up the file anyway (so internally already does something like file_exists).

Please note that you really should use the tmp_name-key instead of the name-key. The 'name' key specifies the name of the file on the client's PC, but the tmp_name specifies the name on the server. There are situations when the server renames the file and therefore differs from the name on the users PC.

edited May 23 '17 at 12:21

Community

1
1

answered Jun 09 '12 at 14:49

Martijn

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4
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so take out `if(!empty($_FILES))` and replace with something like `if(!file_exists($_FILES['myflie']['tmp_name']) || !is_uploaded_file($_FILES['myflie']['tmp_name'])) { echo 'No upload'; } ` – webmaster alex l Jun 09 '12 at 14:58
so im trying `if(!file_exists($_FILES['file']['name']) || !is_uploaded_file($_FILES['file']['name'])) { echo 'No upload'; }` and I will change around my `if else` – webmaster alex l Jun 09 '12 at 15:00
I think file_exists and is_uploaded_file is double, only using is_uploaded_file is sufficient. So you could use either: `if (is_uploaded_file($_FILES['file']['tmp_name']))` or the negation of the predicate. Please note that in your last comment you used the name-key instead of the tmp_name-key. For proper working, you should feed is_uploaded_file with the tmp_name key! – Martijn Jun 09 '12 at 15:05
No joy, now the file field is skipped no matter if its filled or not...hummm – webmaster alex l Jun 09 '12 at 15:05
Ok, but my php script moves the image from the tmp_name to the folder once the upload is done so doesnt that mean the tmp_name is no longer on the server? Also, if the field is blank and no image is on the server to start with, what would `is_uploaded_file` check against? – webmaster alex l Jun 09 '12 at 15:08
WONDERFULL..(happy dance) it worked to a tea. Thanks for all the help! – webmaster alex l Jun 09 '12 at 15:11
I guess your PHP script moves the upload after you've used is_uploade_file to check whether something was uploaded, so that shouldn't be a problem. If the field is blank and no image is on the server, is_uploaded_file would check against nothing and return the required result: false ;) – Martijn Jun 09 '12 at 15:12

score 0 · Answer 2 · edited May 23 '17 at 12:29

please be sure to add

enctype="multipart/form-data"

attribute in you form tag . and follow @Martijn guidelines check the below code, it must work. be sure to customize .

 <?php
 // connect to datebase
 require "master.db.php";


 // this if(empty statement is not working?
 // should be checking to see if the form field 'file' is populated if so check file
 // type if not skip and update sql database with information in form field 'test'

 if(!empty($_FILES)) // MEANS form is valid ( have valid file and other data) 
 {
$sql="UPDATE `characters` SET test='$test' WHERE ID='$id'";
$result=mysql_query($sql);

  if (((($_FILES["file"]["type"] == "image/gif")
  || ($_FILES["file"]["type"] == "image/jpeg")
  || ($_FILES["file"]["type"] == "image/pjpeg"))
  && ($_FILES["file"]["size"] < 2097152)) && $result ))
{
    // code you need to execute
    echo "<b>Update successful</b> <br />";
    echo "<a href='test.html'>View result</a>";
    touch('master.html');
    clearstatcache();
   }

   else
   {
    // wrong file type
    echo "Invalid file <br />";
    echo "Tryed to upload: " . $_FILES["file"]["name"] . "<br />";
    echo "Type: " . $_FILES["file"]["type"] . "<br />";
    echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb Max 2Mb <br />";
    echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br />";
    die;
    }
    }
   else 
   { 
echo "data is not valid";
    }
  ?>

@webmasteralexl : hey have to tried the above code,i edited it according to your needs . — Paritosh Piplewar, Jun 10 '12 at 13:07

php if else error with form field

2 Answers2