How many extension to test for problem

[geroid]

Further to my previous post. I'm checking the extension of an upload to see if it's valid. I only want images file. I have the following questions:

1. Am I including all the possible extensions here? Are there any more I should be including.

2. What is a good max file size limit for an image file?

3. Should I forget the max file size limit and simply resize the image?

4. How do I mark a post as solved?

 

I use the following test:

 

if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png") && ($extension != "gif"))

{

//print error message

echo '<h3>This is an unknown file extension! Please try again</h3>';

$errors=1;

 

 

 

[waynew]

$allowed_filetypes = array("image/gif"=>".gif","image/jpeg"=>".jpeg","image/pjpeg"=>".jpeg");
if(!array_key_exists($_FILES['uploadedfile']['type'],$allowed_filetypes)){
		return false;
}

[trq]

The best way to check if an uploaded file is an image is to run it through getimagesize, this will return false if the file is not an image. File extension meen nothing to Linux, hence theres no point relying upon the to determine a file type.

[geroid]

Thanks. I'm looking at getimagesize function now. Can I just ask if the size of an image is important? That is does it matter? If I am going to restrict upload based on the image size, then what should the size limit be and as I said, should I just determine the size and resize accordingly instead of restricting.

[trq]

  Quote

Can I just ask if the size of an image is important?

 

Only you can answer that. I doupt you'll want people uploading 500mg files though.

[geroid]

Hi thorpe

Just two things. Can you give me a sensible limit to work with? The second thing is this. If I use the getimagesize function to determine if its an image or not will this be safe. What I mean is there are many types of images files. Will getimagesize recognise them but more importantly, would a browser be able to handle them or should I just confine the type tp jpeg, gif, png etc.?