Re: [PHP] Using fopen or SQL to check image

[Karl Cifius]

Thanks Ashley and Peter for your suggestions, I've definitely learned  
some new stuff here.


Best,
Karl


On 25 jun 2010, at 21.07, Peter Lind peter.e.l...@gmail.com wrote:

On 25 June 2010 21:02, Ashley Sheridan a...@ashleysheridan.co.uk  
wrote:


On Fri, 2010-06-25 at 21:01 +0200, Peter Lind wrote:

On 25 June 2010 20:59, Ashley Sheridan a...@ashleysheridan.co.uk  
wrote:


On Fri, 2010-06-25 at 20:57 +0200, Peter Lind wrote:

On 25 June 2010 19:35, Ashley Sheridan a...@ashleysheridan.co.uk  
wrote:

On Fri, 2010-06-25 at 19:31 +0200, Karl Cifius wrote:


Hi,

I'm making a Facebook application that can generate images to  
user's
albums. To publish a story a thumbnail of this image is stored  
on my
server. Since this server currently is very limited I want to be  
able

to clean these thumbnails pretty often.

To not get broken links in older facebook stories the address to  
the
thumbnail is a php script that checks if the thumbnail is  
available

and returns it, or otherwise returns a default thumbnail.

I have solved this using the following code:

$tImage = $_GET['i'];
$tURL   = upload/$tImage.jpg;
if(!($fp=fopen($tURL,rb))){
   header(Location: thumb.jpg);
}else{
   header(Location: upload/$tImage.jpg);
   fclose($fp);
}

My question is if it would be better to have a mysql database with
information about the thumbnail and check if the image is there,
instead of checking if the image file can be loaded? What is the  
most

optimized approach if I start to gain traffic?


Thanks,

/Karl




I think checking for the existence of a file is probably going to  
be the
quicker approach. Unless you have a server with loads of RAM and  
your DB
is very small, it's unlikely your DB will exist entirely in  
memory, so
you will at some point have to access the files that the DB uses,  
even

though this is done by the server automatically.

On another note, I would try to sanitise that $_GET variable a  
bit, as
it could lead to issues down the line later. Maybe limit the  
string to

patterns you expect for an image URL.

Thanks,
Ash
http://www.ashleysheridan.co.uk



Might be quicker to do with a .htaccess file - you can avoid  
loading php at all.


Regards
Peter



PHP can do things that .htaccess can't, like verify a specific ID  
has access to an image, etc.




I must've missed the part in the code where the ID was checked ...
Nope, still can't find it.

Regards
Peter


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It wasn't in the example, but generally I've found the only reason  
someone ever thinks of doing something like this rather than  
directly link to the image is for some sort of validation reason. I  
assumed it was a slimmed-down code sample that only showed us what  
we needed.




Ahh, I see. I assumed the OP would have told us if that was the case -
I prefer answering the stated questions instead of guessing at what
they are.

Regards
Peter

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[PHP] Using fopen or SQL to check image

[Karl Cifius]

Hi,

I'm making a Facebook application that can generate images to user's  
albums. To publish a story a thumbnail of this image is stored on my  
server. Since this server currently is very limited I want to be able  
to clean these thumbnails pretty often.


To not get broken links in older facebook stories the address to the  
thumbnail is a php script that checks if the thumbnail is available  
and returns it, or otherwise returns a default thumbnail.


I have solved this using the following code:

$tImage = $_GET['i'];
$tURL   = upload/$tImage.jpg;
if(!($fp=fopen($tURL,rb))){
  header(Location: thumb.jpg);
}else{
  header(Location: upload/$tImage.jpg);
  fclose($fp);
}

My question is if it would be better to have a mysql database with  
information about the thumbnail and check if the image is there,  
instead of checking if the image file can be loaded? What is the most  
optimized approach if I start to gain traffic?



Thanks,

/Karl