Question

I have been manipulating image files after uploading in the usual way like moving the file from the /tmp folder to a preferred folder of the site.

Now i want to manipulate images by keeping them in the temp folder and once i have done with it then i want to move it to the preferred folder.

What i am trying to do is …

1. Showing a very simple custom file upload dialog.
2. Select an image and click upload.
3. The form is submitted to an iframe so i can show a progressing bar.
4. The php script will echo the javascript code which will call a parent window function from the iframe to notify that the image has been uploaded.
5. I wanted to show another dialog which will display the image from the tmp folder so that the user can resize and crop.
6. When the user selects a region on the image to crop i will send the coordinates to the server and will manipulate the image in the tmp folder.
7. When the image manipulation has been done i want the final image to be moved to my target folder.

here are my doubts.

1. How long will the temp image be there in the tmp folder.
2. How do i display the image in the temp folder in my dialog box because i only have its physical path.
3. I think i can do it like <img src='fetchfromtmp.php?filename>. isn’t it?

4. and in the php script i can readfile the image like readfile(‘tmp/tmpfile’).

   So, finally, will manipulating from temp folder holds good?. will it be effective/suggestive?. What could be the complications? if any.

   I would like to have suggestions and alternatives for my idea.
   Thank you.

Answer 1

I don’t think you should use the temp folder like this, unfortunately, you will have to create your own (or use a database to store the images). The reasons are your point 1 & 2:

1. An image is only guaranteed to stay in the temp folder until the script that uploaded it is finished running. This means that whatever script your form submits it to should move it somewhere safe
2. Usually, this temp folder will be somewhere that isn’t visible to the user. You can hack something like you’ve suggested, but then you have to be very sure of what you’re doing to avoid creating any security leaks.