Need help with php image uploading form

[iNko]

Hello, iv found some guides on how to make this form with restrictions, but some of them are not working.

 

Problems that im having with this:

1) It uploads an image even if its size is bigger than the MAX_SIZE (it shows a message that the file size is too big but uploads anyway) (if i pick a file thats not jpeg/png/jpg/gif it wont upload tho).

2) When i press submit button w/o selecting any files, it gives me the message that file was uploaded. (do i need to add an 'else' in the if(isset) part?)

3) Dunno how to explain this, but when pick some non-image file and click submit, it gives me that the file type is bad (witch it should), however when i choose an image file right after this and click submit again (it says that type is bad again), if i pick same image file for the 3rd time and click submit it gives me the message that it was uploaded.

Same if i do it backwards:

I) pick image, submit - "file uploaded"

II) pick non-image, submit - "file uploaded"

III) pick non-image, submit -"bad type"

 

Heres the code that i have (i left it with comments, idk if i should have removed them or not):

<?php
//define a maxim size for the uploaded images in Kb
define ("MAX_SIZE","20"); 

//This function reads the extension of the file. It is used to determine if the
// file  is an image by checking the extension.
function getExtension($str) {
         $i = strrpos($str,".");
         if (!$i) { return ""; }
         $l = strlen($str) - $i;
         $ext = substr($str,$i+1,$l);
         return $ext;
}

//This variable is used as a flag. The value is initialized with 0 (meaning no 
// error  found)  
//and it will be changed to 1 if an errro occures.  
//If the error occures the file will not be uploaded.
$errors=0;
//checks if the form has been submitted
if(isset($_POST['Submit'])) 
{
	//reads the name of the file the user submitted for uploading
	$image=$_FILES['image']['name'];
	//if it is not empty
	if ($image) 
	{
	//get the original name of the file from the clients machine
		$filename = stripslashes($_FILES['image']['name']);
	//get the extension of the file in a lower case format
  		$extension = getExtension($filename);
		$extension = strtolower($extension);
	//if it is not a known extension, we will suppose it is an error and 
        // will not  upload the file,  
//otherwise we will do more tests
if (($extension != "jpg") && ($extension != "jpeg") && ($extension !=
"png") && ($extension != "gif")) 
		{
	//print error message
			echo '<script type="text/javascript"> 
window.onsubmit=function(){alert("Blogas failo formatas!");} 
</script>';
			$errors=1;
		}
		else
		{
//get the size of the image in bytes
//$_FILES['image']['tmp_name'] is the temporary filename of the file
//in which the uploaded file was stored on the server
$size=filesize($_FILES['image']['tmp_name']);

//compare the size with the maxim size we defined and print error if bigger
if ($size > MAX_SIZE*1024)
{
echo '<script type="text/javascript"> 
window.onsubmit=function(){alert("Per didelis failo dydis!");} 
</script>';
$errors=1;
}

//we will give an unique name, for example the time in unix time format
$image_name=time().'.'.$extension;
//the new name will be containing the full path where will be stored (images 
//folder)
$newname="uploads/".$image_name;
//we verify if the image has been uploaded, and print error instead
$copied = copy($_FILES['image']['tmp_name'], $newname);
if (!$copied) 
{
echo '<script type="text/javascript"> 
window.onsubmit=function(){alert("Nepavyko ikelti failo!");} 
</script>';
$errors=1;
}}} 
}

//If no errors registred, print the success message
if(isset($_POST['Submit']) && !$errors )
{
	echo '<script type="text/javascript"> 
window.onsubmit=function(){alert("Failas ikeltas!");} 
</script>';
} 
?>

<!--next comes the form, you must set the enctype to "multipart/frm-data" 
and use an input type "file" -->
<form name="newad" method="post" enctype="multipart/form-data"  
action="">
<label for="file" id="label">Pasirinkti failą: </label>
<input type="file" name="image" id="file">
<input name="Submit" type="submit" value="įkelti" id="submit">
</form>

 

thx in advance

[onlyican]

Where shall i start

 

1) DONT rely on the file type being the file extension.

list($origWidth, $origHeight, $fileType = getimagesize($myFile);

$standardFileTypes   = array(1    => 'gif',
                                          2    => 'jpg',
                                          3    => 'png',
                                          4    => 'swf',
                                          5    => 'pnd',
                                          6    => 'bmp', 
                                          7    => 'tiff', 
                                          8    => 'tuff',
                                          9    => 'jpc',
                                          10    => 'jp2',
                                          11    => 'jpx', 
                                          12    => 'jb2',
                                          13    => 'swc', 
                                          14    => 'iff',
                                          15    => 'wbmp',
                                          16    => 'xbm');
            
$fileExt = $standardFileTypes[$fileType];

 

 

2: You check if the file size is too big but you dont stop execution

 

if($var1 == $var2){
// If the condition is true, execute this
}

// Execute this, regardless of the above if statement

 

Check if file exists and not empty

if(isset($_FILES['field']['tmp_name']) && $_FILES['field']['tmp_name']['size'] > 0){

}else{
// Nothing to upload
}

[iNko]

thx for the fast reply, any ideas why the onsubmit() function isnt working properly?

 

it works with some delay, i have to do the same action twice for it to display (everything else works, it uploads the file just shows delayed message) the correct message

[onlyican]

Why are you using JavaScript onSubmit()

 

This function is normally used when you want to track a submit on a form. not throughout the website.

 

If you want a simple echo at that point, use php echo, else just use JavaScript alert.

[iNko]

tyvm, everything works now